Rendering

February 15, 2018 | Author: Mayur Sachdeva | Category: Rendering (Computer Graphics), Texture Mapping, Shader, Copyright, Auto Cad

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Rendering

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Contents

Chapter 1

About rendering and renderers . . . . . . . . . . . . . . . . . . 1 Rendering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Introduction to rendering . . . . . . . . . . . . . . . . . . . . . . 1 Hardware, software, and vector rendering . . . . . . . . . . . . . . 2 Renderers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Maya Software renderer . . . . . . . . . . . . . . . . . . . . . . . 4 Maya Hardware renderer . . . . . . . . . . . . . . . . . . . . . . . 5 Maya Vector renderer . . . . . . . . . . . . . . . . . . . . . . . . . 8 mental ray for Maya renderer . . . . . . . . . . . . . . . . . . . . 11 Select a renderer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

Chapter 2

Camera set up . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 Cameras . . . . . . . . . . . . . . . . . . . . . Viewing cameras vs. rendering cameras . Maya camera types . . . . . . . . . . . . Motion blur and depth of field . . . . . . . . . Focus and blur . . . . . . . . . . . . . . . fStop (aperture) and shutter speed/angle . Motion blur . . . . . . . . . . . . . . . . Framing objects with a camera . . . . . . . . . Camera aim . . . . . . . . . . . . . . . . Angle of view (focal length) . . . . . . . . Safe display regions for TV production . .

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Clipping planes . . . . . . . . . . . . . . . . . . . . . . . Create and use a camera . . . . . . . . . . . . . . . . . . . . . . Create a camera . . . . . . . . . . . . . . . . . . . . . . . Adjust a camera’s attributes . . . . . . . . . . . . . . . . . Make an existing camera renderable . . . . . . . . . . . . Turn scene view guidelines on or off . . . . . . . . . . . . Adjust depth of field . . . . . . . . . . . . . . . . . . . . Camera limitations . . . . . . . . . . . . . . . . . . . . . Look through (select) a camera . . . . . . . . . . . . . . . Select the current scene view’s camera . . . . . . . . Look through another camera . . . . . . . . . . . . Frame your scene . . . . . . . . . . . . . . . . . . . . . . Move a camera to another location . . . . . . . . . . Aim a camera . . . . . . . . . . . . . . . . . . . . . Look at selected objects . . . . . . . . . . . . . . . . Frame selected objects . . . . . . . . . . . . . . . . Frame all objects . . . . . . . . . . . . . . . . . . . Frame part of a scene . . . . . . . . . . . . . . . . . Save sequential camera movements . . . . . . . . . Troubleshoot Resolution Gate and Film Gate display incorrectly . . . . . . . . . . . . . . . . . . . . . . Using a stereoscopic camera . . . . . . . . . . . . . . . . . . . Create a stereoscopic camera . . . . . . . . . . . . . . . . Edit the anaglyph attributes of a stereoscopic camera . . . Render a scene with stereoscopic camera . . . . . . . . . . Create a custom rig . . . . . . . . . . . . . . . . . . . . .

Chapter 3

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Tessellation and Approximation . . . . . . . . . . . . . . . . . 39 Tessellation and approximation . . . . . . . . . . . . . . Introduction to Tessellation and Approximation . . Maya tessellation . . . . . . . . . . . . . . . . . . Primary vs. secondary tessellation passes . . . NURBS surface, poly, and subD tessellation . Tessellate NURBS surfaces . . . . . . . . . . . . . . . . . View Maya tessellation settings for an object . . . . Adjust NURBS tessellation settings . . . . . . . . . Determine which objects to tessellate . . . . . . . Display NURBS tessellation triangles . . . . . . . . Use span-based tessellation . . . . . . . . . . . . . Tessellate polygonal surfaces . . . . . . . . . . . . . . . Adjust polygonal tessellation . . . . . . . . . . . . Tessellate subdivision surfaces . . . . . . . . . . . . . . Display subdivision surface tessellation triangles . . Adjust subdivision surface tessellation . . . . . . .

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Chapter 4

Visualize and render images . . . . . . . . . . . . . . . . . . . 47 Rendering methods . . . . . . . . . . . . . . . . . . . . . . . . Interactive Photorealistic Rendering (IPR) . . . . . . . . . Render View rendering . . . . . . . . . . . . . . . . . . . Batch renders from within Maya (UI) . . . . . . . . . . . . Render from a command line . . . . . . . . . . . . . . . . Render output . . . . . . . . . . . . . . . . . . . . . . . . . . . File formats . . . . . . . . . . . . . . . . . . . . . . . . . Subfolders and names of rendered images . . . . . . . . . File output location . . . . . . . . . . . . . . . . . . . . . Pixel aspect ratio . . . . . . . . . . . . . . . . . . . . . . Resolution . . . . . . . . . . . . . . . . . . . . . . . . . . Frames vs. Fields . . . . . . . . . . . . . . . . . . . . . . . Color, Depth, and Mask (alpha) channels . . . . . . . . . Pre Render MEL and Post Render MEL scripts . . . . . . . Layers and passes . . . . . . . . . . . . . . . . . . . . . . . . . Render layer overview . . . . . . . . . . . . . . . . . . . . Working with render layers: different layer examples . . . Render layer concepts . . . . . . . . . . . . . . . . . . . . Mask and depth channels . . . . . . . . . . . . . . . . . . Render passes . . . . . . . . . . . . . . . . . . . . . . . . Compositing Interoperability Plug-in . . . . . . . . . . . . . . . Compositing Interoperability Plug-in for Toxik . . . . . . Render tiles in the Maya Software renderer . . . . . . . . . . . . Render tiles . . . . . . . . . . . . . . . . . . . . . . . . . Visualize scenes and render images . . . . . . . . . . . . . . . . A typical rendering workflow . . . . . . . . . . . . . . . . Choose a rendering method . . . . . . . . . . . . . . . . Set scene options . . . . . . . . . . . . . . . . . . . . . . Open the Render Settings window . . . . . . . . . . Render all or some objects from a camera . . . . . . Set the rendered image file format . . . . . . . . . . Set file name syntax . . . . . . . . . . . . . . . . . . Set rendered images output location . . . . . . . . . Set the resolution and pixel aspect ratio . . . . . . . Enable color, depth, and mask channels for rendered images . . . . . . . . . . . . . . . . . . . . . . . . Create and view depth files . . . . . . . . . . . . . . Modify a mask channel . . . . . . . . . . . . . . . . Specify frame or field rendering . . . . . . . . . . . Run Pre Render MEL or Post Render MEL scripts . . . Adjust anti-aliasing . . . . . . . . . . . . . . . . . . Adjust output image filtering . . . . . . . . . . . . . Create and load a plug-in multipixel filter . . . . . . Set raytracing quality . . . . . . . . . . . . . . . . . Set motion blur . . . . . . . . . . . . . . . . . . . .

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Contents | vii

Maya software . . . . . . . . . . . . . . . . . . . . . . . . . 97 Set IPR options . . . . . . . . . . . . . . . . . . . . . . . . 98 Set Paint Effects rendering options . . . . . . . . . . . . . . 99 Set per-material vector rendering options . . . . . . . . . . 99 Work with render layers . . . . . . . . . . . . . . . . . . . . . . 100 Work with layers . . . . . . . . . . . . . . . . . . . . . . . 100 Work with layer overrides . . . . . . . . . . . . . . . . . . 102 Remove material overrides from objects in any render layer . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105 Assign different component shading for each render layer . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108 Work with attribute overrides . . . . . . . . . . . . . . . . 109 Preview layers . . . . . . . . . . . . . . . . . . . . . . . . 111 Render layers to PSD format . . . . . . . . . . . . . . . . . 115 Batch and command-line render with layers . . . . . . . . 116 Duplicate an existing render layer . . . . . . . . . . . . . . 118 Naming render layers . . . . . . . . . . . . . . . . . . . . 119 Recycling rendered images to save time . . . . . . . . . . . 119 Control visibility/reflection per layer . . . . . . . . . . . . 120 Merging display layers or render layers when importing files . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122 Visualize a scene . . . . . . . . . . . . . . . . . . . . . . . . . . 123 Visualize interactively with IPR . . . . . . . . . . . . . . . 123 See shading and lights in a scene view . . . . . . . . . . . 126 Test render a low-res still or frame . . . . . . . . . . . . . . 127 Test render a low-res animation . . . . . . . . . . . . . . . 128 Render selected objects . . . . . . . . . . . . . . . . . . . 129 Render a region of your scene . . . . . . . . . . . . . . . . 130 Perform final renders from within Maya . . . . . . . . . . . . . 131 Render a single frame . . . . . . . . . . . . . . . . . . . . 131 Batch render a still or animation . . . . . . . . . . . . . . 131 Render with several processors . . . . . . . . . . . . . . . 132 Perform command line rendering . . . . . . . . . . . . . . . . . 133 Command line rendering . . . . . . . . . . . . . . . . . . 133 Render multiple scenes . . . . . . . . . . . . . . . . . . . . . . 135 Render multiple scenes . . . . . . . . . . . . . . . . . . . 135 Work with the Compositing Interoperability plug-in . . . . . . . 135 Work with Autodesk Toxik 2007 . . . . . . . . . . . . . . 135 Work with Autodesk Toxik 2008 . . . . . . . . . . . . . . 139 Troubleshooting Rendering . . . . . . . . . . . . . . . . . . . . 140 Troubleshoot image plane displays black swatch . . . . . . 140 Troubleshoot displacement is not displayed . . . . . . . . 140 Troubleshoot software-rendered is too bright . . . . . . . . 141 Troubleshoot Multi-UVs for NURBS don’t software render . . . . . . . . . . . . . . . . . . . . . . . . . . . 141

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Troubleshoot NURBS surface does not appear when rendering . . . . . . . . . . . . . . . . . . . . . . . . . Troubleshoot rendered image doesn’t match interactive window display . . . . . . . . . . . . . . . . . . . . . Troubleshoot projection texture swims over an animation . . . . . . . . . . . . . . . . . . . . . . . . Troubleshoot transparent blobby surface rendering anti-aliasing problem . . . . . . . . . . . . . . . . . . Troubleshoot memory exceptions . . . . . . . . . . . . . Troubleshoot highlight artifacts close to object edge . . . Troubleshoot background surfaces show through . . . . Troubleshoot objects vibrate when an animation is rendered as fields . . . . . . . . . . . . . . . . . . . . . Troubleshoot 2D Motion Blur problems . . . . . . . . . Troubleshooting Surfaces (Maya software) . . . . . . . . Troubleshoot edits in the Texture Editor don’t update in IPR . . . . . . . . . . . . . . . . . . . . . . . . . . . . Troubleshoot looping renders . . . . . . . . . . . . . . . Troubleshoot render tiles . . . . . . . . . . . . . . . . . Troubleshoot assigning objects to Render Layers through the Relationship editor . . . . . . . . . . . . . . . . . Troubleshoot render layer color indicators do not appear correctly (Linux only) . . . . . . . . . . . . . . . . . . Troubleshoot Interactive Photorealistic Rendering (IPR) . . . . . . . . . . . . . . . . . . . . . . . . . . .

Chapter 5

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Quality, render speed, diagnostics . . . . . . . . . . . . . . . 153 Image quality and render speed . . . . . . . . . . . . . . . . The speed/quality tradeoff . . . . . . . . . . . . . . . . Anti-aliasing and flicker . . . . . . . . . . . . . . . . . Artifacts . . . . . . . . . . . . . . . . . . . . . . . . . Render speed . . . . . . . . . . . . . . . . . . . . . . . Maya render diagnostics . . . . . . . . . . . . . . . . . Improve rendered image quality . . . . . . . . . . . . . . . . Adjust scene anti-aliasing parameters (Maya software) . Adjust per-object anti-aliasing parameters . . . . . . . Reduce artifacts and flicker . . . . . . . . . . . . . . . Increase render speed . . . . . . . . . . . . . . . . . . . . . Increase overall rendering speed . . . . . . . . . . . . . Increase surface rendering speed . . . . . . . . . . . . Increase shadow rendering speed . . . . . . . . . . . . Increase camera views render speed . . . . . . . . . . . Global illumination and caustics . . . . . . . . . . . . Final Gather . . . . . . . . . . . . . . . . . . . . . . . Reduce render memory usage . . . . . . . . . . . . . . Reducing memory usage . . . . . . . . . . . . . .

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Contents | ix

Cache texture tiles using BOT (block ordered texture) . . . . . . . . . . . . . . . . . . . . . . Delete information not relevant to the renderer . Render parts of a scene separately . . . . . . . . . Decrease file size (Maya Vector renderer) . . . . . . . . Strategies to decrease vector render file size . . . . Diagnose scene problems . . . . . . . . . . . . . . . . . . . Run diagnostics . . . . . . . . . . . . . . . . . . . . . Sample diagnostic messages . . . . . . . . . . . . . . .

Chapter 6

Network

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mental ray for Maya rendering . . . . . . . . . . . . . . . . . 173 About the mental ray renderer . . . . . . . . . . . . . . . About the mental ray for Maya renderer . . . . . . Motion Blur . . . . . . . . . . . . . . . . . . . . . . . . mental ray for Maya motion blur . . . . . . . . . . Approximation in mental ray for Maya . . . . . . . . . . Approximation . . . . . . . . . . . . . . . . . . . . Approximation nodes . . . . . . . . . . . . . . . . Approximation styles . . . . . . . . . . . . . . . . mental ray for Maya geometry types . . . . . . . . Visualize and render images . . . . . . . . . . . . . . . . Command line render . . . . . . . . . . . . . . . . Exporting .mi files . . . . . . . . . . . . . . . . . . Multi-render passes . . . . . . . . . . . . . . . . . Quality, render speed, diagnostics . . . . . . . . . . . . . mental ray for Maya diagnostics . . . . . . . . . . . Converting textures to optimized format . . . . . . Network rendering . . . . . . . . . . . . . . . . . . . . . Overview of network rendering . . . . . . . . . . . mental ray for Maya network rendering . . . . . . . mental ray network rendering: Satellite and standalone . . . . . . . . . . . . . . . . . . What you need to set up network rendering . Configuration files . . . . . . . . . . . . . . . mental ray for Maya reference links . . . . . . . . . . . . mental ray for Maya Output window messages . . . . . . Work with mental ray for Maya approximation . . . . . Create an approximation node . . . . . . . . . . . Assign an approximation node . . . . . . . . . . .

x | Contents

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rendering . . . . . . . . . . . . . . . . . . . . . . . 169

Overview of network rendering . . . . . . Maya network rendering . . . . . . . . . . Managing Maya network rendering . Network render with Maya software . . .

Chapter 7

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. 173 . 173 . 180 . 180 . 181 . 181 . 182 . 183 . 184 . 186 . 186 . 186 . 187 . 197 . 197 . 197 . 199 . 199 . 199

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. 199 . 200 . 201 . 202 . 203 . 203 . 203 . 204

Edit an approximation node . . . . . . . . . . . . . . . . . . Unassign an approximation node . . . . . . . . . . . . . . . Delete an approximation node . . . . . . . . . . . . . . . . Override approximation settings . . . . . . . . . . . . . . . Obtain quads for subdivision surfaces . . . . . . . . . . . . . Troubleshoot partial creases rendering as full creases . . . . . Control Fine approximation triangles . . . . . . . . . . . . . Setting Fine approximation cache limit . . . . . . . . . Control Fine approximation triangles . . . . . . . . . Tweak Approximation node settings . . . . . . . . . . Render time smoothing of polygon meshes . . . . . . . . . . . . . Smooth polygon meshes at render time . . . . . . . . . . . . Rendering a smooth polygon mesh . . . . . . . . . . . . . . . . . Render a smooth polygon mesh using Smooth Mesh Preview . . . . . . . . . . . . . . . . . . . . . . . . . . . . Contour rendering . . . . . . . . . . . . . . . . . . . . . . . . . . Adding a contour to your scene . . . . . . . . . . . . . . . . Work with multi-render passes . . . . . . . . . . . . . . . . . . . Introduction to multi-render passes: a simple workflow example . . . . . . . . . . . . . . . . . . . . . . . . . . . Sample workflow for multi-render passes . . . . . . . . . . . Exporting the multi-render passes for compositing in Toxik . . . . Set scene options . . . . . . . . . . . . . . . . . . . . . . . . . . . Open the Render Settings window . . . . . . . . . . . . . . Modify a mask channel . . . . . . . . . . . . . . . . . . . . Adjust anti-aliasing in mental ray for Maya . . . . . . . . . . Set motion blur in mental ray for Maya . . . . . . . . . . . . Perform command line rendering . . . . . . . . . . . . . . . . . . Rendering from the command line . . . . . . . . . . . . . . Export .mi files . . . . . . . . . . . . . . . . . . . . . . . . . . . Export a .mi file and render with mental ray . . . . . . . . . Managing your scenes using render proxies . . . . . . . . . . . . . Using render proxies in your scene . . . . . . . . . . . . . . Material assignments for render proxy . . . . . . . . . . . . Increase render speed . . . . . . . . . . . . . . . . . . . . . . . . Increase overall rendering speed in mental ray for Maya . . . Increase surface rendering speed in mental ray for Maya . . . Increase shadow rendering speed in mental ray for Maya . . Diagnose scene problems . . . . . . . . . . . . . . . . . . . . . . mental ray for Maya error handling and diagnostics . . . . . Network rendering . . . . . . . . . . . . . . . . . . . . . . . . . . Network render with mental ray for Maya . . . . . . . . . . Set up mental ray network rendering . . . . . . . . . . . . . Set up a master machine with mental ray for Maya or mental ray for Maya Satellite . . . . . . . . . . . . . . . . . . . . . Verify which hosts file is being read . . . . . . . . . . . . .

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. 205 . 205 . 206 . 207 . 207 . 208 . 208 . 208 . 208 . 209 . 214 . 214 . 215

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. 215 . 217 . 217 . 218

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. 218 . 224 . 233 . 236 . 236 . 237 . 238 . 239 . 239 . 239 . 241 . 241 . 242 . 242 . 246 . 247 . 247 . 249 . 250 . 251 . 251 . 252 . 252 . 252

. . 254 . . 256

Contents | xi

Change the set of slaves used for mental ray for Maya renders . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 256 Set up a master machine with mental ray standalone (method 1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 257 Set up a master machine with mental ray standalone (method 2) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 258 Slave machine setup . . . . . . . . . . . . . . . . . . . . . . . . 259 Submit a job to render over the network . . . . . . . . . . . . . 262 Dynamic Attributes for mental ray for Maya . . . . . . . . . . . . . . 263 Dynamic Attributes . . . . . . . . . . . . . . . . . . . . . . . . 263 Troubleshoot mental ray for Maya rendering . . . . . . . . . . . . . . 276 Troubleshoot general mental ray for Maya rendering issues . . . 276 Troubleshoot render layers do not render correctly when exporting a .mi file . . . . . . . . . . . . . . . . . . . . . . . . 282 Troubleshoot Motion Blur . . . . . . . . . . . . . . . . . . . . . 282 Troubleshoot Surfaces . . . . . . . . . . . . . . . . . . . . . . . 283 Troubleshoot final gather causes flicker . . . . . . . . . . . . . . 283 Troubleshoot Network rendering with mental ray for Maya . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 284 Troubleshoot exporting .mi files . . . . . . . . . . . . . . . . . . 288

Chapter 8

Appendices . . . . . . . . . . . . . . . . . . . . . . . . . . . . 289 Appendix A: Extra mental ray render settings . . . . . . . . . . . Appendix B: Creating camera output passes with mental ray for Maya . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Appendix C: Additional mental ray for Maya rendering commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . Appendix D: Render layer presets . . . . . . . . . . . . . . . . . Work with layer presets . . . . . . . . . . . . . . . . . . . Render layers example: automotive preview . . . . . . . . Appendix E: Render Passes for Maya software renderer . . . . . . Work with render passes . . . . . . . . . . . . . . . . . . . Appendix F: mental ray user framebuffers . . . . . . . . . . . . . mental ray for Maya user framebuffers . . . . . . . . . . . Create, edit and delete user framebuffers . . . . . . . . . . miDefaultOptions node . . . . . . . . . . . . . . . . . . . mentalrayUserBuffer node attributes . . . . . . . . . . . . mentalrayOutputPass node . . . . . . . . . . . . . . . . .

Chapter 9

Rendering

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. 293 . 294 . 294 . 298 . 301 . 301 . 303 . 303 . 304 . 306 . 307 . 308

menus . . . . . . . . . . . . . . . . . . . . . . . . 309

File . . . . . . . . . . . . . . . . . . . . . . . . . . . File > Export All, Export Selection (mental ray) . Modify . . . . . . . . . . . . . . . . . . . . . . . . . Modify > Convert > Displacement to Polygons . Create . . . . . . . . . . . . . . . . . . . . . . . . .

xii | Contents

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. 309 . 309 . 313 . 313 . 313

Create > Cameras > Camera . . . . . . . . . . . . . . . . . . Create > Cameras > Camera and Aim . . . . . . . . . . . . . Create > Cameras > Camera, Aim, and Up . . . . . . . . . . Window . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Window > Rendering Editors > Render View . . . . . . . . . Window > Rendering Editors > Hardware Render Buffer . . . Window > Rendering Editors > Render Settings . . . . . . . . Window > Rendering Editors > Hypershade . . . . . . . . . Window > Rendering Editors > Rendering Flags . . . . . . . Window > Rendering Editors > Shading Group Attributes . . Window > Rendering Editors > Multilister . . . . . . . . . . Window > Rendering Editors > mental ray > Approximation Editor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Window > Rendering Editors > mental ray > Custom Text Editor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Render . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Render > Render Current Frame . . . . . . . . . . . . . . . . Render > Redo Previous Render . . . . . . . . . . . . . . . . Render > IPR Render Current Frame . . . . . . . . . . . . . . Render > Redo Previous IPR Render . . . . . . . . . . . . . . Render > Test Resolution . . . . . . . . . . . . . . . . . . . . Render > Run Render Diagnostics . . . . . . . . . . . . . . . Render > Batch Render . . . . . . . . . . . . . . . . . . . . . Render > Cancel Batch Render . . . . . . . . . . . . . . . . . Render > Show Batch Render . . . . . . . . . . . . . . . . . Render > Render Using > Maya Hardware . . . . . . . . . . . Render > Render Using > Maya Software . . . . . . . . . . . Render > Render Using > Maya Vector . . . . . . . . . . . . Render > Set NURBS Tessellation . . . . . . . . . . . . . . . Render > Render Using > mental ray . . . . . . . . . . . . . Render > Export All Layers to Toxik 2007 . . . . . . . . . . . Render > Export Selected Layers to Toxik 2007 . . . . . . . . Render > Export to Toxik 2008 . . . . . . . . . . . . . . . . Render > Export Pre-Compositing . . . . . . . . . . . . . . . Panel menus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . View . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . View > Select Camera . . . . . . . . . . . . . . . . . . View > Camera settings . . . . . . . . . . . . . . . . . View > Camera Attribute Editor . . . . . . . . . . . . . View > Camera Tools . . . . . . . . . . . . . . . . . . . View > Image plane . . . . . . . . . . . . . . . . . . . Stereo . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Stereo > Center Eye . . . . . . . . . . . . . . . . . . . Stereo > Active . . . . . . . . . . . . . . . . . . . . . . Stereo > Horizontal Interlace . . . . . . . . . . . . . . Stereo > Checkerboard . . . . . . . . . . . . . . . . . .

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. 313 . 317 . 317 . 318 . 318 . 318 . 318 . 318 . 319 . 319 . 319

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. 319 . 320 . 320 . 321 . 321 . 323 . 323 . 324 . 324 . 326 . 326 . 326 . 327 . 327 . 327 . 334 . 334 . 335 . 336 . 337 . 340 . 340 . 340 . 340 . 345 . 354 . 357 . 358 . 358 . 358 . 358 . 358

Contents | xiii

Stereo > Anaglyph . . . . . . . . . . . . Stereo > Luminance Anaglyph . . . . . . Stereo > Freeview (Parallel) . . . . . . . Stereo > Freeview (Crossed) . . . . . . . Stereo > Background Color . . . . . . . Stereo > Set Color Using Preferences . . Renderer . . . . . . . . . . . . . . . . . . . . Renderer > Default Quality Rendering . Renderer > High Quality Rendering . . . Renderer > . . . . .

Chapter 10

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. 359 . 359 . 359 . 359 . 360 . 360 . 360 . 360 . 360 . 362

Rendering Windows and Editors . . . . . . . . . . . . . . . . 363 Approximation Editor . . . . . . . . . . . . . . mental ray Approximation Editor . . . . . Surface Approximation settings (Attribute Render Layer Editor . . . . . . . . . . . . . . . Render Settings . . . . . . . . . . . . . . . . . . Render Settings window . . . . . . . . . . Render Settings: Common tab . . . . . . . Render Settings: Maya Software tab . . . . Render Settings: mental ray tabs . . . . . . Render Settings: Maya Hardware tab . . . Render Settings: Maya Vector tab . . . . . Create Render Passes window . . . . . . . . . . Custom Stereo Rig Editor . . . . . . . . . . . . Render View . . . . . . . . . . . . . . . . . . . Render View menu bar . . . . . . . . . . . Render View toolbar . . . . . . . . . . . . Rendering Flags . . . . . . . . . . . . . . . . . Rendering Flags window . . . . . . . . . . Hardware Render Buffer . . . . . . . . . . . . . Hardware Render Buffer window . . . . . Hardware Render Buffer global settings . . Hardware Render Buffer menus . . . . . .

Chapter 11

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. . . . . . . . . . Editor) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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. 363 . 363 . 363 . 367 . 376 . 376 . 377 . 388 . 404 . 454 . 459 . 470 . 471 . 472 . 472 . 478 . 482 . 482 . 484 . 484 . 486 . 491

Rendering nodes . . . . . . . . . . . . . . . . . . . . . . . . . 497 Render Layer attributes . . . . . . . . . . . . . . . . . . Render Layer render attributes . . . . . . . . . . . . Render pass nodes . . . . . . . . . . . . . . . . . . . . . Render pass Attribute Editor . . . . . . . . . . . . . Render pass set Attribute Editor . . . . . . . . . . . Render pass contribution map Attribute Editor . . . mental ray for Maya Dynamic Attributes for Rendering . Dynamic Attributes for Rendering . . . . . . . . . . Transform node mental ray attributes . . . . . . . . . . .

xiv | Contents

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Transform node mental ray rendering attributes . Object-specific mental ray attributes - Attribute Editor . mental ray . . . . . . . . . . . . . . . . . . . . . Object-specific render attributes - Attribute Editor . . . Render Stats . . . . . . . . . . . . . . . . . . . . Smooth Mesh Render . . . . . . . . . . . . . . . Vector Renderer Control . . . . . . . . . . . . . . Texture Map . . . . . . . . . . . . . . . . . . . . Tessellation . . . . . . . . . . . . . . . . . . . . . NURBS objects tessellation . . . . . . . . .

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. 505 . 506 . 506 . 511 . 511 . 514 . 515 . 515 . 517 . 517

Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 519

Contents | xv

xvi

About rendering and renderers

1

Rendering Introduction to rendering

Rendering is the final stage in the 3D computer graphics production process. Though the wider context of rendering begins with shading and texturing objects and lighting your scene, the rendering process ends when surfaces, materials, lights, and motion are processed into a final image or image sequence.

Visualization vs. the final render As you build your scenes (shade and texture objects, light scenes, position cameras, and so on), you’ll want to visualize your scene many times before you produce the final rendered image or image sequence. This process may involve

1

(depending on your particular project) creating and setting up additional cameras. Visualize a scene during early iterations to detect and correct image quality problems or to estimate and reduce the amount of time the final render takes before you spend time performing the final render. When you are satisfied with the results of your scene during test renders, you can perform the final render. You can visualize and final render a single frame, part of an animation (multiple frames), or an entire animation in Autodesk® Maya®.

The key to successful rendering The key to rendering is finding a balance between the visual complexity required and the rendering speed that determines how many frames can be rendered in a given period of time. Rendering involves a large number of complex calculations which can keep your computer busy for a long time. Rendering pulls data together from every sub-system within Maya and interprets its own data relevant to tessellation, texture mapping, shading, clipping, and lighting. Producing rendered images always involves making choices that affect the quality (anti-aliasing and sampling) of the images, the speed with which the images are rendered, or both. The highest quality images typically take the most time to render. The key to working efficiently is to produce good-enough quality images in as little time as possible in order to meet production deadlines. In other words, choose only the most economical values for options that let you produce images of acceptable quality for your particular project.

Hardware, software, and vector rendering Software rendering Software rendering produces images of the highest quality, letting you achieve the most sophisticated results. Computation occurs on the CPU, as opposed to hardware rendering, which relies on the machine’s graphics card. Because it is not restricted by the computer's graphics card, software rendering generally is more flexible. The

2 | Chapter 1 About rendering and renderers

trade-off, however, is that software rendering is generally more time consuming. Exactly what you can render depends on which software renderer you use and its particular limitations. Maya has the following software renderers: ■

The Maya software renderer To find out about Maya’s software renderer, see Maya Software renderer on page 4.

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mental images® mental ray® for Maya® To find out about mental ray for Maya, see About the mental ray for Maya renderer on page 173.

Hardware rendering Hardware rendering uses the computer's video card and drivers installed on the machine to render images to disk. Hardware rendering is generally faster than software rendering, but typically produces images of lower quality compared to software rendering. In some cases, however, hardware rendering can produce results good enough for broadcast delivery. Hardware rendering cannot produce some of the most sophisticated effects, such as some advanced shadows, reflections, and post-process effects. To produce these kind of effects, you must use software rendering. Maya has the following hardware renderer: ■

The Maya hardware renderer To find out Maya’s hardware renderer, Maya Hardware renderer on page 5. NOTE ■

Maya displays a warning message if your video card is not qualified for hardware rendering, which can affect the display in the scene view (for example, Toon shading). In this case, shading in the scene view is what you get with non-High Quality rendering, or when not using the hardware renderer.

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For information about the Hardware Render Buffer, see Hardware Render Buffer window on page 484.

Hardware, software, and vector rendering | 3

Vector rendering Vector rendering lets you create stylized renderings (for example, cartoon, tonal art, line art, hidden line, wireframe) in various bitmap image formats and 2D vector formats. Maya has the following vector renderer: ■

The Maya vector renderer To find out about Maya’s vector renderer, see Maya Vector renderer on page 8.

Renderers Maya Software renderer Maya’s software renderer is an advanced, multi-threaded renderer. It is based on a rendering technology that is built directly into Maya's dependency graph architecture, which means its feature nodes can be intimately connected with any other feature in Maya. It provides artists with an excellent general purpose rendering solution with very broad capabilities. It is a hybrid renderer, offering true raytracing plus the speed advantages of a scan-line renderer. The Maya software renderer, while not slow, tends to favor quality and wide breadth of capability over raw speed. The Maya software renderer supports all of the various entity types found within Maya including particles, various geometry and paint effects (as a post render process) and fluid effects. It also has a robust API for the addition of customer-programmed effects. The Maya software renderer features IPR (Interactive Photo Realistic rendering), a tool designed to allow you to make interactive adjustments to the final rendered image, and which greatly enhances rendering productivity. Most importantly, the nature of Maya's integrated architecture allows complex interconnections, like procedural textures and ramps that govern particle emission and other unpredictable relationships that are capable of producing stunning visual effects.

4 | Chapter 1 About rendering and renderers

Maya Hardware renderer Maya’s hardware renderer presents a seamlessly integrated rendering solution that leverages the ever increasing power of next-generation graphics cards to render frames. Benefits include an intuitive workflow to generate hardware rendered images for previews, specific passes, and hardware rendered particles. You can render and display images using the Render View, which lets you compare images during the shading and lighting tasks. The user experience and the visual quality of the final images significantly surpass that of the Hardware Render Buffer window on page 484. You can produce broadcast-resolution images in less time than with software rendering. In some cases, the quality may be good enough for final delivery. The hardware renderer uses Maya's existing interface and workflow for assigning shaders, textures, particles, light linking, and so on. To prevent the windows of other applications from interfering with the rendering of the image, you can perform off-screen batch rendering.

Highlights of supported features These features are processed natively on the graphics card to improve quality and speed in many cases. Supported features include: ■

Display a layered texture and create multiple UV sets for each different texture

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Negative light. Frame buffer format on page 455 must be set to floating point. Select RGBA: 16-bit float per channel from the drop down list in the Render Settings: Maya Hardware tab on page 454.

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Displacement mapping

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Direct input of normal maps

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Shader translucency

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Blinn shaders

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Ramp shaders

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Integrated rendering workflow and interface

Maya Hardware renderer | 5

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Polygons and NURBS geometry

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Multiple textured channels

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Advanced transparency

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Hardware particles

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Instancing

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Point, Directional, Spot, and Ambient Light types

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Any number of lights

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Light linking

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Per-vertex and per-pixel shading effects

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Multi-pass and multi-sampling anti-aliasing

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File textures for any supported channel

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On-the-fly procedural and shading network conversions

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Specular highlights

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Bumps

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Reflections

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Shadows

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Motion blur

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RBG color, alpha matte (mask), and Z depth output

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Command line rendering

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Render diagnostics, such as warnings for unsupported primitives, shaders, and light types and light features

Supported hardware and platforms Only specific hardware and platform combinations are supported by hardware rendering. For more information, see: http://www.autodesk.com/qual-charts

6 | Chapter 1 About rendering and renderers

Limitations of the hardware renderer ■

The Maya hardware renderer does not support subdivision surfaces.

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BOT files are not supported by the hardware renderer. BOT file textures will be rendered black by the hardware renderer.

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Hardware renderer does not support point light shadows. Shadows are not created for point lights when the hardware renderer is used.

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When displaying mental ray area lights, the hardware renderer does not provide the same results as an actual render, but instead produces a very rough approximation that can be viewed in High Quality mode. The Maya hardware renderer supports the following configuration for mental ray area lights: ■

A Maya area light must be used.

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Only the Rectangle mental ray area light shape is supported.

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Basic light parameters such as Color, Intensity, Decay Rate are supported.

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An approximation of shadows is supported.

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A fixed point sampling rate is used for both diffuse and specular highlights. Sampling artifacts may occur, especially for specular highlights where the area of the light is large and the light is close to the surface.

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Other light shapes and options such as High Samples, High Sample Limit and Low Samples are not supported.

Light linking for instanced lights Hardware rendering supports per light-instance light linking. For example, two instances of a light shape can have different light linking. For a light instance to illuminate the scene, the light instance should be connected to a light linker node, either indirectly through a light set, or directly through a transform node or a shape node. If the light shape node is connected to a light linker node, all the instances of the light shape are affected. The Light Linking Editor does not support instance light linking, so making per-instance light linking must be done indirectly by using light sets.

Maya Hardware renderer | 7

For example, put light_instance1 and light_instance2 in separate light sets, and set light linking relationship of each of the light sets. Breaking the light linking of a light_instance directly in the Light Linking Editor (as opposed to through lightset) operates on the light shape, resulting all the instances of the light shape breaking.

Maya Vector renderer (Microsoft® Windows® 32-bit and Apple® Mac OS® X) You can use the Maya Vector renderer to create stylized renderings (for example, cartoon, tonal art, line art, hidden line, wireframe) in various bitmap image formats (for example, IFF, TIFF, and so on) or in the following 2D vector formats: ■

Adobe® Flash® (non-interactive) version 3, 4 or 5 (SWF)

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Adobe® Illustrator® version 8 (AI)

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Encapsulated PostScript Level 2 (EPS)

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Scalable Vector Graphics (SVG).

To select the Maya Vector renderer, see Select a renderer on page 11. To set options for the Maya Vector renderer, see Render Settings window on page 376. Example Animations

helicopter.swf

8 | Chapter 1 About rendering and renderers

flowers.swf

Example Animations

boat.swf

car.swf

NOTE ■

The Maya Vector renderer cannot render certain Maya features (see Maya features that do not vector render on page 10).

■

If you are rendering SWF or SVG files for online delivery make sure you read Strategies to decrease vector render file size on page 165. Otherwise you may create files that are too large for online delivery.

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Due to some limitations in technology, (upon which the vector renderer is based), increasing the resolution in the Render Settings does not necessarily produce better results.

Maya Vector renderer | 9

Maya features that do not vector render The Maya Vector renderer cannot render the following Maya features. Maya Feature

Notes

Bump maps

Not rendered.

Displacement maps

Not rendered. Use Modify > Convert > Displacement to Polygons to convert displacement maps to polygons for rendering.

Maya® Fluid Effects™

Not rendered. Use Modify > Convert > Fluid to Polygons to convert fluid effects to polygons for rendering.

Image planes

Not rendered.

Lights

Only point lights are used during rendering. Only the following light attributes are considered during rendering: light location, light color, Emit Specular, Use Depth Map Shadows, Use Ray Trace Shadows.

Maya® Fur™

Not rendered.

Multiple UVs

Not rendered.

Maya® Paint Effects™

Not rendered. Use Modify > Convert > Paint Effects to Polygons to convert paint effects to polygons for rendering. Some Paint Effects may not render as expected. Many Paint Effects brushes use a transparency texture on a single polygon to achieve an effect (for example, the outline of a leaf). However, the Maya Vector renderer only supports per object transparency.

Particles

Not rendered.

10 | Chapter 1 About rendering and renderers

Maya Feature

Notes

Post-render effects

Not rendered. (Post-render effects include motion blur, fog, glows, and so on.)

Shaders

Anisotropic, Lambert, Blinn, Phong and Phong E shaders should produce expected results. Other Maya shaders may produce unexpected results.mental ray shaders and custom shaders are not rendered.Multiple shaders assigned to a single NURBS or subdivision surface are not rendered.

Textures

Texture rendering is limited by the Fill Style and the number of polygons. Fill styles that fill individual polygons (Full Color and Mesh Gradient) render textures more accurately than other fill styles, and models that contain more polygons render textures more accurately than models with fewer polygons.

By Frame

By Frame is ignored in Vector rendered filenames

mental ray for Maya renderer For information regarding the mental ray for Maya renderer, see About the mental ray for Maya renderer on page 173.

Select a renderer To find out more about Maya renderers, see the following: ■

Maya Software renderer on page 4

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Maya Hardware renderer on page 5

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Maya Vector renderer on page 8

mental ray for Maya renderer | 11

■

mental ray for Maya renderer on page 11

When you select a renderer, Maya’s user interface is automatically configured to use the renderer. For example, if you render the current frame, Maya uses the renderer to process the image and display it in the Render View. Or, if you press the Display Render Settings window button, the Render Settings window on page 376 appears, showing the Common tab and tab that corresponds to the selected renderer. To choose the renderer 1 Do one of the following: ■

Click Render > Render Using, then choose the renderer.

■

Select the renderer from the drop-down list in Render View (Window > Rendering Editors > Render View).

■

Select the renderer from the drop-down list in the Render Settings window on page 376. NOTE The mental ray renderer and the Maya Vector renderer are plug-ins that are loaded by default. If you do not see them listed in Render > Render Using, choose Window > Settings/Preferences > Plug-in Manager and make sure the Mayatomr and, or VectorRender plug-ins are loaded.

To specify the default renderer 1 Click Window > Settings/ Preferences > Preferences. 2 Select the Rendering category, then set the Preferred Renderer option.

12 | Chapter 1 About rendering and renderers

Camera set up

2

Cameras Viewing cameras vs. rendering cameras Whenever you look at your scene in Maya, whether you are building your scene or ready to render images, you are looking through a camera. Think of it as being a director on a movie set and looking through a camera lens. Your field of view is restricted to what you can see through that lens. By default, Maya has four cameras that let you view your scene in a panel: the perspective camera and the three orthographic cameras (side, top, front) that correspond to the default scene views. You look through these cameras (panels) as you model, animate, shade, and texture objects. (For more information about views, see Main window in the Basics guide.) Typically, you don’t use these default cameras to render a scene; you create one or more perspective cameras from which to render. The only difference between a rendering camera and any other camera through which you can view your scene is a flag that allows it to render the scene. For more information on the kind of cameras you can create, see Maya camera types on page 14. To create a camera, see Create a camera on page 22.

13

Maya camera types Maya cameras have certain advantages over real world cameras, giving you more creative freedom. For example, because Maya cameras are not restricted by size or weight, you can move cameras to any position in your scene, even inside the smallest objects.

Static and animated cameras Three types of cameras help you create both static and animated scenes: ■

Use a Basic camera for static scenes and for simple animations (up, down, side to side, in and out), such as panning out of a scene. See Create > Cameras > Camera on page 313 for more details.

■

Use a Camera and Aim camera for slightly more complex animations (along a path, for example), such as a camera that follows the erratic path of a bird. See Create > Cameras > Camera and Aim on page 317 to set its options.

■

Use a Camera, Aim, and Up camera to specify which end of the camera must face upward. This camera is best for complex animations, such as a camera that travels along a looping roller coaster. See Create > Cameras > Camera, Aim, and Up on page 317 to set its options.

Stereoscopic Camera

Use stereoscopic cameras to create scenes that you want a three-dimensional effect. Camera rigs can also be customized by using MEL or Python scripting or using the Custom Stereo Rig Tool. See Custom Stereo Rig Editor on page 471 to set it options.

14 | Chapter 2 Camera set up

Motion blur and depth of field Focus and blur The process of recording what you see through a real-world camera is simple: you press the button that opens the shutter, which lets light through the aperture, which in turn exposes the film to light, recording what you see. A camera’s exposure settings determine depth of field (the region of sharp focus), and whether or not subject matter is crisp or blurred by motion. Especially if you using photography based images in your scene (such as live action footage), you may need to work with some camera settings. You set these and other settings, such as the film back or focal length, in: ■

The selected camera’s Attribute Editor. See Adjust a camera’s attributes on page 22.

■

As options for a camera as you create it. See Create > Cameras > Camera on page 313.

fStop (aperture) and shutter speed/angle In real-world photography, together the fStop and shutter speed (or shutter angle for film cameras) determine how much light is exposed to film. However, fStop and shutter speed also determine what is in focus, to a certain extent, but for very different reasons. The length of time light is allowed to pass through the camera lens to the film is determined by the shutter speed. The higher the speed, the shorter the exposure time, the less light exposed to the film. The amount of light that is allowed to pass through the camera lens to the film is determined by the camera’s aperture setting (also known as the fStop). The wider the aperture, the more light exposed to the film.

Motion blur and depth of field | 15

NOTE A still camera’s shutter speed performs the same function as a film camera’s shutter angle. The shutter angle is a metal disk that is missing a pie-shaped section. This disk sits between the lens and the film, and rotates at a constant rate. When the missing section is in front of the film, it allows light from the lens to pass through and expose the film. The larger the angle of the pie-shaped section, the longer the exposure time, and moving objects appear more blurry. For more information, see Shutter Angle on page 353.

Shutter speed/angle determines motion blur Motion blur gives the feeling of motion. Motion blur is determined by the shutter speed. The slower the shutter speed (sometimes deliberately done), the harder motion is to stop. That is, fast motion (such as a moving car) appears motion blurred at slower shutter speeds. At higher speeds, the moving car is ‘stopped’ and therefore in focus. To set motion blur in Maya, see Motion blur on page 16. For information on mental ray for Maya’s motion blur, see mental ray for Maya motion blur on page 180.

Aperture determines Depth of Field (DOF) Depth of field is the region of sharp focus in a photograph. Depth of field is determined by the camera’s aperture setting. At wide aperture settings (for example, at fStop f/2), the depth of field is shallow, and more of the foreground and background (that brackets the area in sharp focus) is out of focus. At narrow aperture settings (for example, at fStop f/22), the depth of field is deep, and more of the foreground and background is in focus. To adjust a camera’s fStop to affect the depth of field, see Adjust depth of field on page 25.

Motion blur Motion blur can be turned on and off on a per-object basis. If some surfaces in the scene don’t move, or move only slightly, do not motion blur them. Being selective about what you motion blur can decrease rendering times. (See also 2D Motion Blur global attributes information about 2D motion blur.)

16 | Chapter 2 Camera set up

Related topics ■

mental ray for Maya motion blur on page 180

Framing objects with a camera Camera aim Aim a camera to frame objects in your scene. To look through a camera, see Select the current scene view’s camera on page 26. To frame your scene in other ways, see Move a camera to another location on page 27.

Camera tools Camera tools let you reposition the camera in different ways.

Tumble Revolves the camera around a center of interest (such as a particular object), or the camera’s pivot point (which, by default, is the center). To adjust the way in which the Tumble tool works, see View > Camera Tools on page 354.

Track Slides the camera horizontally or vertically in space. To adjust the way in which the Track tool works, see View > Camera Tools on page 354.

Dolly Moves the camera into the view, or backs the camera out of the view. When you use the Dolly tool, you change the perspective; that is, objects far from the camera change in relative size at a slower rate than objects which are close to the camera. Compare to Zoom (see Zoom on page 18).

Framing objects with a camera | 17

You can use the Dolly tool in a perspective view or an orthographic view. To adjust the way in which the Dolly tool works, see View > Camera Tools on page 354. TIP You can also use platform-specific keyboard combinations for most camera tools. See Selection, tools, and actions in the Basics guide for details.

Zoom Changes the focal length (viewing angle) on the camera. The Zoom tool does not change perspective like the Dolly tool does; all objects in the frame change size at the same rate. The camera doesn’t move, but the effect is similar. To move in or out of the view without changing the viewing angle, see Dolly. To adjust the way in which the Zoom tool works, see View > Camera Tools on page 354.

Roll Rotates the camera around its horizontal axis, down the barrel of the lens. To adjust the way in which the Roll tool works, see View > Camera Tools on page 354.

Azimuth Elevation Revolves the camera around a point of interest in perspective view only. The angle of a camera’s sight line relative to the ground plane is called its elevation; the angle of a camera’s sight line relative to a plane perpendicular to the ground plane is called its azimuth. To adjust the way in which the Azimuth Elevation tool works, see View > Camera Tools on page 354.

Yaw-Pitch Points the camera up or down (pitch, also called tilt), or left or right (yaw, also called pan) without moving the camera. The scene in the camera’s view appears to move in the opposite direction. To move the camera up or down or side to side, use the Track tool. To adjust the way in which the Yaw-Pitch tool works, see View > Camera Tools on page 354.

18 | Chapter 2 Camera set up

Fly Flies the camera through the scene with no constraints. The Fly Tool lets you navigate your scene as if you were playing a 3D first-person perspective game. To use the Fly Tool, Ctrl+drag up to fly forward and down to fly backward. To change the camera direction, release the Ctrl key and drag. TIP Tumble, track, and dolly are available while the Fly Tool is active.

Angle of view (focal length) For every shot, you decide how big an object appears in the frame. For example, should a shot include an entire character or just its head and shoulders? There are two ways to make an object larger in the frame. You can either move the camera closer to the object (see Dolly on page 17) or adjust the lens to a longer focal length (see Zoom on page 18). The focal length of a lens is the distance from the center of the lens to the film plane. The shorter the focal length, the closer the focal plane is to the back of the lens. Lenses are identified by their focal length. Focal length is expressed in millimeters or, on occasion, in inches (1 inch is approximately 25mm).

The object’s size in the frame is directly proportional to the focal length. If you double the focal length (keeping the distance from the camera to the object constant), the subject appears twice as large in the frame. The size of the object in the frame is inversely proportional to the object’s distance from the camera. If you double the distance, you reduce the size of the object by half in the frame.

Angle of view (focal length) | 19

Angle of view As you adjust the camera’s focal length, the angle of view narrows and expands. This is what causes objects to get larger or smaller in the frame. As you extend the focal length, the angle of view gets narrower. As you shorten the focal length, the angle of view gets larger.

Safe display regions for TV production

You can display a guideline that indicates a region within which you should keep all action or text if you plan to display the rendered images on a television screen. Action and text within these guidelines is visible on every television. Different TV manufacturers use different tubes and put them in different boxes, so there’s a difference in what gets displayed; safe action and text region are broadcast standards that assure action or text (respectively) is visible. Safe text is 80% of the screen because the sensitivity to logotypes (fonts) is much higher than the sensitivity to objects moving; that is, at the 10% edge of the tube, text appears warped. Safe action is 90%. To turn the safe action or safe title border on or off, see Turn scene view guidelines on or off on page 24.

Safe action The safe action view guide represents 90% of the rendering resolution (the resolution gate).

20 | Chapter 2 Camera set up

Safe Title The safe title view guide represents 80% of the rendering resolution (the Resolution Gate). For example, in this image, the title DANCER does not fit within the Safe Title area. Track the scene until the title fits within the border.

Clipping planes Near and far clipping planes are imaginary planes located at two particular distances from the camera along the camera’s sight line. Only objects between a camera’s two clipping planes are rendered in that camera’s view. Any parts of objects in the scene closer to the camera than the near clipping plane, or farther from the camera than the far clipping plane, are not rendered.

If part of an object is in front of the near clipping plane, then only the part of the object beyond the near clipping plane is rendered. If part of an object

Clipping planes | 21

is beyond the far clipping plane, the entire object is rendered, including the part beyond the far clipping plane. A completely opaque object which is behind the far clipping plane is clipped. If that object’s transparency is greater than 0, the part behind the far clipping plane is clipped. NOTE For Maya software rendering, if refractions are toggled on, an object that intersects the far clipping plane is not clipped regardless of the transparency value.

Create and use a camera Create a camera To learn more about Maya cameras, see Maya camera types on page 14. To create a new camera 1 Select Create > Cameras > camera type > camera.

, where Type is the type of

To find out about the type of cameras, see Maya camera types on page 14. The Create Camera Options window appears. NOTE If you’ve previously set the options for the type of Camera you want to create, you can just select the camera type; you don’t have to set its options each time. 2 Set the camera options, then click Create. For a description of the camera options, see Create > Cameras > Camera on page 313.

Adjust a camera’s attributes A camera’s attributes describe various properties of the camera, including angle of view, focal length, and depth of field.

22 | Chapter 2 Camera set up

To adjust a camera’s attributes 1 Select the camera. To select a camera, see Select the current scene view’s camera on page 26. The camera’s Attribute Editor appears (unless it’s been hidden). If it does not, click View > Camera Attribute Editor.... 2 Set attributes. For a description of the attributes, see View > Camera Attribute Editor on page 345.

Make an existing camera renderable By default, your scene has only one renderable camera (the original perspective camera) that can render all objects in your scene. If you add another camera to your scene and want to make it renderable (or you would like to make one of the existing cameras renderable), you must set the camera to renderable. You can have multiple renderable cameras. Set your list of renderable cameras in the Render Settings window (Window > Rendering Editors > Render Settings). To make a camera renderable 1 Open the Render Settings window by selecting Window > Rendering Editors > Render Settings. 2 Click on the Common Tab and locate the Renderable Cameras section. 3 To set another renderable camera, select Add Renderable Camera from the drop-down list. A new Renderable Camera section appears. Select from the drop-down list the additional camera that you would like to make renderable. Repeat until all of the cameras that you wish to make renderable are displayed. 4 To make a camera unrenderable, click the beside the camera name. This will remove it from the list of renderable cameras but not delete the camera from the scene. See Renderable Cameras on page 382 for more information regarding the Renderable Cameras option.

Make an existing camera renderable | 23

NOTE ■

Advanced users can turn off the Renderable attribute in the Output Settings section of the Attribute Editor for the cameras you do not want to render from.

■

For Maya software rendering, you can also select a camera (or several cameras) to render from when you render from a shell or command line. Use Render and the ?cam option. See Render from a command line on page 53 for information about command line rendering.

Turn scene view guidelines on or off You can turn view guidelines on or off so that you can correctly determine safety boundaries for certain types of information: safe action and text for TV broadcasts, or render borders. TIP You can display several view guides at the same time by opening the camera’s Attribute Editor (View > Camera Attribute Editor...), and turning on options in the Display Options section. To learn more about the safe action and safe title border or the resolution gate, see Safe display regions for TV production on page 20. To turn the safe action border on or off 1 Click View > Camera Settings > Safe Action. To turn the safe title border on or off 1 Click View > Camera Settings > Safe Title. To display the Resolution Gate view guide 1 Select View > Camera Settings > Resolution Gate from the view’s menu bar. The resolution gate and the resolution values appear.

24 | Chapter 2 Camera set up

Adjust depth of field You can view the calculated distance of the camera from the object and apply that value to the Focus Distance for the camera to achieve Depth of Field effects in the Camera’s Attribute Editor. For information on depth of field, see Focus and blur on page 15. NOTE ■

To create an image that has wider depth of field (more area in front of and behind the subject that is in focus) use high fStop values, such as f16, f22, f32. To achieve narrow depth of field (less area in front and behind the subject that is in focus) use low fStop values such as f2.8, f4 or f5.6. For more information on fStops, see fStop (aperture) and shutter speed/angle on page 15.

■

Depending on the fStop and Focus Region Scale values, parts of the object may or may not be in focus.

To ensure the center of an object is in focus for Depth of Field 1 Select the object in the view. 2 Make sure Object Details is turned on in the Heads Up Display menu. (Object Details is on by default). Notice the Distance from Camera value. 3 Use the Distance from Camera value as the Focus Distance value in the Depth of Field section for the current Camera.

If you select multiple objects, Maya uses the center of their bounding box to calculate the distance from the camera.

Adjust depth of field | 25

Camera limitations Look Through Selected Look Through Selected can produce unexpected results if the camera is duplicated, or the scene is saved.

Manipulator undo and two- or three-node cameras Manipulator undo does not work for two- or three-node cameras.

Problems if camera not proportionally scaled Problems exist if the camera is not proportionally scaled. The view and render will be skewed and manipulation may result in odd behavior.

Look through (select) a camera Select the current scene view’s camera Select the current scene view’s camera to show the camera’s Attribute Editor (unless it’s been hidden) or to aim the camera while you are looking through it. For more information about scene views, which are in fact cameras, see Viewing cameras vs. rendering cameras on page 13. To select the current view’s camera 1 In the view, click View > Select Camera.

Look through another camera If you have more than one camera, you can switch the camera with which you are viewing the scene to another one.

26 | Chapter 2 Camera set up

To look through a camera 1 Do one of the following: ■

To look through a camera that is selected, click Panels > Look Through Selected.

■

To look through another camera, click Panels, then select the camera name from either the Perspective or Orthographic submenus.

Frame your scene Move a camera to another location You can display a camera as an object in a view and use the standard manipulators to move it. This is like holding a camera through which you are not looking and moving it from one place to another (from a bag to a table for example); your hands are the manipulator. Moving a camera this way is particularly useful if you want to see the camera’s path or adjust frustum or clipping planes, for example. To move a camera while looking through it, see Aim a camera on page 27. To move a camera 1 Select the camera, then use the Move tool. For more information on the Move tool, see the Basics book.

Aim a camera You can aim the current view’s camera with camera tools. Aiming is like holding the camera up to your eye, then pointing up, down, or moving yourself around your subject matter to frame objects in the scene. To move a camera through which you are not looking, see Move a camera to another location on page 27.

Frame your scene | 27

To use a camera tool 1 In the view, do one of the following: ■

Click View > Camera Tools, select the tool you want to use, then drag the cursor to use the tool.

■

Click View > Camera Tools >

■

For a description of the tool settings, see View > Camera Tools on page 354.

■

TIP

, set the options, then click close.

■

You can use the keyboard combinations to Tumble, Track, and Dolly the camera. See Selection, tools, and actions in the Basics guide for details.

■

If you change the default settings in the camera tool options windows, remember to press the Reset Tool button to reset the tool defaults for the next operation.

■

Select View > Default Home if you zoom and tumble the view repeatedly and then need to see the default camera’s view.

28 | Chapter 2 Camera set up

TIP If you want to aim your camera down a curve path, you can attach your camera to the curve by following these steps: 1 Create Camera and Aim. The camera's hierarchy should consist of the following nodes: camera_group, camera, and camera_aim. 2 Create 2 locators. Move the locators so that the first locator is at the same location as the camera and the second locator is at the same location as the camera's aim. 3 Parent camera_group under first locator. 4 Parent camera_aim under second locator. 5 Select the first locator and the curve and create a Motion Path by selecting Animate > Motion Paths > Attach to Motion Path> . In the Attach to Motion Path Options window, select Z as the Front Axis. Make sure that Follow and Bank are checked; then, click Attach. 6 Parent the second locator under the first locator. 7 Turn on Snap to Curve and then Ctrl-drag the second locator to the curve. The locator should snap to the curve. 8 Play the animation. The camera should stay aimed down the curve path. If the camera is moving backwards along the curve, try moving the locator to the other side of the curve.

Look at selected objects To look at selected objects 1 Select View > Look At Selection. 2 The camera moves to show selected objects in the center of the camera’s view.

Frame your scene | 29

Frame selected objects To look at and fill the view with selected objects 1 Select View > Frame Selection (or press the hotkey f). 2 The camera moves to fill the camera’s view with selected objects.

Frame all objects To look at and fill the view with all objects in a scene 1 Select View > Frame All (or press the hotkey a). 2 The camera moves to fill the camera’s view with all objects in the scene (including lights and cameras, if their icons are displayed in the view). NOTE View fit may have problems with some joints, where it will zoom out too far.

Frame part of a scene To look at and fill the view with a region of a scene 1 Ctrl+Alt+drag over the region. 2 The camera moves to fill the camera’s view with the selected region.

Save sequential camera movements You can write all camera movements to the Script Editor to let you undo or redo camera movements or copy camera movements to use them for other cameras or scenes. To save camera movements to the Script Editor 1 In the view panel, select View > Camera Settings > Undoable Movement.

30 | Chapter 2 Camera set up

Troubleshoot Resolution Gate and Film Gate display incorrectly Resolution Gate and Film Gate may not correctly display with non-standard Film Fit Offsets, when Film Fit is set to Vertical or Fill. Workaround: The Horizontal setting works correctly.

Using a stereoscopic camera

With the stereo plug-in you can create three dimensional renders with the illusion of a three dimensional depth of field.When rendering a stereoscopic scene, Maya takes into account all of the stereoscopic camera attributes, and performs calculations to produce an anaglyph or parallel image that can be composited by another program. In this section you will learn how to: ■

Create a stereoscopic camera on page 32

■

Edit the anaglyph attributes of a stereoscopic camera on page 33

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Render a scene with stereoscopic camera on page 34

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Create a custom rig on page 34.

Using a stereoscopic camera | 31

Create a stereoscopic camera

1 In this scene there are 3 NURBS Primitives, a cube, a cone and a sphere. 2 From the main menu bar, select Create > Cameras > Stereo Camera. An icon with three cameras appear, indicating that a stereo camera has been created. TIP It is best to set up the scene first with your objects, then create a stereoscopic camera. 3 Select the middle camera of the stereoRig. The middle camera of the rig affects the left and right camera attributes that impact the anaglyph effect for the left and right eye. 4 In the Transform node, rename the stereoCamera to exampleCamera. 5 Select the left and right cameras and rename them to exampleCameraLeft and exampleCameraRight. 6 In the viewport menu, select Panels > Stereo > exampleCamera. The viewport switches to stereo mode and you are viewing the scene changes to the stereo camera’s viewpoint. The Stereo menu appears in the Viewport menu. From the Stereo menu you can choose among different types of 3-D simulations, for example Horizontal Interlace, Checkerboard and Freeview (Crossed). These views are dependent upon specific hardware settings. In this example we will work with Anaglyph. 7 Move and rotate the camera so that you can view the Nurbs objects in the viewport. NOTE You may want to change your background color by selecting Stereo > Background color to have a better view in stereo mode. You have now created and named a stereoscopic camera for your scene. In the next steps you will be adjusting the attributes of the cameras to fine tune the anaglyph effect.

32 | Chapter 2 Camera set up

Edit the anaglyph attributes of a stereoscopic camera

Use the Interaxial Separation and Zero Parallax settings to adjust the anaglyph effect. 1 In the viewport select Stereo > Anaglyph. The scene changes to the anaglyph perspective view. 2 In the Outliner double click on exampleCamera. 3 In the Attribute Editor under the Stereo section heading, set Interaxial Separation to 0. The red and cyan imaging of the grid and the Nurbs objects are nowmerged. NOTE You need colored anaglyph or red and cyan glasses to view the 3-D effect. 4 Slowly move the Interaxial Separation slider to the right. The 3-D depth of field effect starts to appear as the left and right camera move away from the center camera. You can adjust the focus of objects in the background by adjusting the Zero Parallax. If you move the slider too far the effect will not appear correct due to the left and right camera being too far apart. You have now created a simple anaglyph effect with a stereoscopic camera. Now you can render out the images from each camera.

Related topics ■

View > Camera Attribute Editor on page 345

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Stereo on page 358

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Render View menu bar on page 472

Edit the anaglyph attributes of a stereoscopic camera | 33

Render a scene with stereoscopic camera

When rendering out a scene with a stereoscopic camera, Maya renders out the individual left and right camera images. The images have to be composited in order to apply the desired stereo effect. 1 Open the Render View window by selecting Window > Rendering Editors > Render View. 2 In the Render View window select Render > Render >

You have now selected your stereo camera for rendering 3 To view your render output in other stereo modes select Display > Stereo Display

Create a custom rig

There are two ways you can add a custom rig camera to a scene. ■

Method 1: Write a rig creation method using a MEL or Python script and register the rig in Maya. This is the preferred method.

■

Method 2: Edit an existing rig to be recognizable by Maya.

Method 1 Writing a MEL or Python script procedure 1 Create your custom rig by writing a MEL/Python Script. TIP It is best to create a rig using Python scripting. 2 Describe the hierarchy of your camera rig and define the relationship of the your center, left and right cameras.

34 | Chapter 2 Camera set up

All your rig nodes must be parented under one camera, directly or through any number of transforms. This camera serves as the root of your rig, and as the center camera. It is not possible to use instancing inside the rig structure. The creation procedure should take no arguments, and must return an array of three strings. The first is the root node of the rig, and the second and third are the left and right cameras, respectively. See StereoRig Manager in the Commands documentation for examples: stereoRigManager in the Command documentation Registering your custom rig 1 Select Window > Rendering Editors > Custom Stereo Rig Editor The Custom Stereo Rig Editor window appears.

2 In the Register a new rig section, select a name for your custom rig. Select the language that you used to create your custom rig, either Python or MEL. Enter the Python or MEL procedure that you want to use to create your custom rig, for example: maya.app.stereo.stereoCameraComplexRig.createRig.

3 Click Add New Rig. You can now access your custom rig in by selecting Panels > Stereo > New Stereo Camera (). NOTE You can also register your custom rig by using the stereoRigManager command. Refer to the stereoRigManager commands documentation for examples on how to register a custom rig, query the default rig, or delete a rig using this command.

Create a custom rig | 35

Source code examples Maya ships with a default stereo rig enabled. The source code is available in the python module: …\Python\Lib\site-packages\maya\app\stereo. Within this directory, you can also find the following code examples: ■

stereoCameraDefaultRig.py is the procedure used to create default Maya

rigs. ■

stereoCameraComplexRig.py creates a more complex rig, using 3 pairs of

cameras. ■

stereoCameraHierarchicalRig.py creates a similar setup as stereoCameraComplexRig, using 3 copies of Maya default rig, parented under another camera.

…\scripts\others\stereoCameraSimpleRig.mel creates the simplest rig, where

a camera is used for both the right and center eye. A left camera is parented underneath. These scripts are used in the stereoRigManager example.

Method 2 Making an existing rig Maya compliant If you have an existing rig, or if you need to create a rig outside of Maya, you can make an existing rig compliant with Maya’s requirements. However, all cameras must be parented under a common transform, called the rig root. Call this Python code: import maya.cmds as cmds from maya.app.stereo import stereoCameraRig # Make sure the stereo plug-in is loaded cmds.loadPlugin("stereoCamera", quiet=True) stereoCameraRig.makeStereoCameraRig(rigRoot, rigTypeName, leftCam, rightCam)

where rigRoot, leftCam and rightCam are the names of the root transform, and the left and right camera pair. rigNameType is a user defined string used to identify the rig type.

36 | Chapter 2 Camera set up

Change the default left and right camera pair If you have a rig with multiple left and right camera pairs, you can change the default left and right pair, used for interactive display. Call this Python code: import maya.cmds as cmds from maya.app.stereo import stereoCameraRig # Make sure the stereo plug-in is loaded cmds.loadPlugin("stereoCamera", quiet=True) stereoCameraRig.setStereoPair(rigRoot, leftCam, rightCam)

Create a custom rig | 37

38

Tessellation and Approximation

3

Tessellation and approximation Introduction to Tessellation and Approximation

Tessellation (called approximation in mental ray for Maya) is the process renderers use to convert NURBS surfaces (or displacement mapped polygon meshes) to triangles. Triangles determine how smooth an object looks at closer distances to you (the camera). When poorly tessellated objects are close to the camera, they appear faceted; when they are further away, they don’t.

When to adjust tessellation Because (most) renderers can only render triangles, tessellation is a necessary and automatic step that occurs at render time. However, you need to adjust tessellation settings when objects aren’t smooth enough, which typically happens as objects come close to the camera or if objects are displacement mapped.

39

Tessellation settings determine how many triangles are used, where the triangles are concentrated, and what size they are. Numerous and concentrated triangles increase the memory requirements (which in turn decrease performance) of the renderer, so you must adjust tessellation settings to strike a balance between smooth edges (quality) on objects that are closer to the camera and renderer performance (the time it takes to render). Tessellation strategy always is to adjust the settings, per-object (not globally), only high enough to achieve a smooth surface. Distant and less-important objects can have lower tessellation settings than objects closer to the camera.

Related topics ■

Approximation on page 181

■

Create an approximation node on page 203

Maya tessellation Primary vs. secondary tessellation passes Primary tessellation is a first pass through the geometry that creates a specific number of triangles in the U and V directions of the surface; it places triangles evenly all over the surface, regardless of curviness or displacement. Secondary tessellation (also called Adaptive tessellation) is a second pass that creates more triangles only where needed. With Maya software rendering and hardware, you can set basic and advanced tessellation settings. Basic tessellation (for novice users) performs both primary and secondary tessellation, in the following ways: ■

curvature tolerance affects the chord height ratio of the secondary attributes

■

u/v divisions affects the number U/V, and uses per-span # of isoparms

If basic tessellation doesn’t provide you with the required results, choose advanced tessellation, and make adjustments accordingly.

40 | Chapter 3 Tessellation and Approximation

NURBS surface, poly, and subD tessellation You don’t need to adjust tessellation for polygon meshes or subdivision surfaces unless those surfaces are displacement mapped. A NURBS surface is composed of one or more patches. (For more information on NURBS surfaces see Degree of NURBS curves and surfaces in the NURBS Modeling guide.) During rendering, each patch is divided into an appropriate number of triangles to approximate the true shape of the surface.

You can set NURBS tessellation on all or selected objects (see Render > Set NURBS Tessellation on page 327), or on an individual basis by selecting an object and adjusting the settings in the object’s Attribute Editor.

Tessellate NURBS surfaces View Maya tessellation settings for an object See Primary vs. secondary tessellation passes on page 40 for information on Maya’s default tessellation settings. To view Maya tessellation settings for an object 1 Select the object whose tessellation settings you want to view. 2 Open the Attribute Editor (CTRL+a). 3 Click the shape tab (for example, nurbsSphereShape1). The shape node’s attributes appear. 4 Expand the Tessellation section.

Tessellate NURBS surfaces | 41

Adjust NURBS tessellation settings NOTE Some of the advanced tessellation parameters can dramatically increase rendering times. Because the tessellation of NURBS surfaces has nothing to do with the material assigned to the surface (unless the surface is displacement mapped), you can start adjusting tessellation early in the process, anytime after the object is modeled. To adjust tessellation on NURBS objects 1 Determine which objects in the scene you have to adjust tessellation settings. See Determine which objects to tessellate on page 43. 2 Display the tessellation triangles so you can visualize your adjustments. See Display NURBS tessellation triangles on page 43. 3 Select the object(s) for which you want to adjust tessellation. If you want to apply settings to All surfaces, skip this step. 4 Select Render > Set NURBS Tessellation > Tessellation Options window.

to open the Set NURBS

5 Choose either Selected Surfaces or All surfaces (see Selected Surfaces, All Surfaces). 6 Switch the Tessellation Mode from Automatic (default) on page 328 to Manual on page 328. (You can also adjust some of the Automatic tessellation settings to optimize the default settings. See Automatic Mode settings on page 328.) 7 Select either Basic on page 330 or Advanced on page 330 tesselation. Always start with the Basic settings. Basic lets you adjust a smaller number of settings that automatically determine some of the more advanced settings. NOTE Some of the advanced tessellation parameters can dramatically increase rendering times, so choose them wisely. 8 Test render to see the results.

42 | Chapter 3 Tessellation and Approximation

Fine-tune the adjustments you’ve just set until you reach an adequate level of smoothness. TIP To prevent overtessellation of objects, use the Use Smooth Edge on page 330attribute in the Render > Set NURBS Tessellation on page 327 window to increase tessellation only along the edge of the object.

Determine which objects to tessellate What models are going to be used are usually determined during the pre-production phase of a project. Based on storyboards, you will know their positions in the scene and distance to the camera. Determine which objects never get close to the camera and which ones either are (for static images) or do (for animated objects). ■

If an object is far from the camera at all times, decrease the default settings.

■

If the object is middle distance away from the camera, leave the default settings.

■

If the object gets close to the camera at some point during the scene, increase the tessellation settings a little more, but only enough to achieve an acceptable level of smoothness.

Display NURBS tessellation triangles To display tessellation triangles 1 Select the NURBS surface(s) you want to see. 2 In the Tessellation section of the NURBS object’s Attribute Editor, turn on Display Render Tessellation.

Determine which objects to tessellate | 43

Use span-based tessellation To use span-based tessellation 1 In the Tessellation section of the surface’s Attribute Editor, turn on Enable Advanced Tessellation and set Mode U and Mode V to Per Span # of Isoparms. Guidelines are as follows: To use span-based tessellation 1 Turn on Smooth Edge. Open the Common Tesselation Options section of the Attribute Editor to access the Smooth Edge check box.

Tessellate polygonal surfaces Adjust polygonal tessellation To set polygonal tessellation 1 Select the polygonal object for which you want to set tessellation. 2 Click Window > Attribute Editor, in Tessellation Attributes section to adjust the attributes.

Tessellate subdivision surfaces Display subdivision surface tessellation triangles To see subdivision surface tessellation triangles 1 Select the object. 2 Click Modify > Convert > Subdiv to Polygons to convert the subdivision surface to a polygonal surface to use as a temporary visualization object.

44 | Chapter 3 Tessellation and Approximation

Adjust subdivision surface tessellation To set subdivision tessellation 1 Select the subdivision object for which you want to set tessellation. 2 Click Window > Attribute Editor, in Tessellation Attributes section to adjust the attributes.

Adjust subdivision surface tessellation | 45

46

Visualize and render images

4

Rendering methods Interactive Photorealistic Rendering (IPR) IPR is available only for Maya software rendering and mental ray for Maya rendering.

IPR, a component of the Render View rendering, lets you preview and adjust lights, shaders, textures, and 2D motion blur quickly and efficiently. IPR is ideal for visualizing your scene as you work because it almost immediately shows the changes you make. You can also pause and stop IPR rendering and select several rendering options to be included or excluded from the IPR process.

47

IPR works a little differently than regular software rendering; if you need to know more about how it works, see How IPR works on page 48. IPR doesn't support all software renderable features (for example, raytracing or production quality anti-aliasing are not supported). See IPR Limitations (for Maya software renderer) on page 49.

How IPR works When you start an IPR session, Maya computes the initial IPR image, which is a deep raster format that contains more than just the final picture. Maya performs all the visibility calculations (only once), and stores the results in a file in the iprImages directory. An IPR image is an IFF image with additional data. It is larger than a regular image file because it stores both visibility and shading data. The data is computed in the following ways: ■

Visibility calculations compute where items are located in the scene, or what is visible to the camera (or to the light, for depth maps for shadowing) at each pixel in the image.

■

Shading calculations compute what color is displayed at each pixel of the image. NOTE An IPR image is not part of the scene file; it only represents what the scene looks like from a specific camera or light, at a specific time. You can reuse an IPR image as you work on the scene, but remember that the IPR image may be out of sync with the scene as you adjust it and move objects in the views.

The data in this format is used to efficiently adjust shading and lighting parameters in an interactive way. To adjust IPR options, see IPR Options on page 402. NOTE For advanced users: You can batch process IPR images ahead of time from the command line, so you can then adjust several frames of the same animation, in which the visibility data may vary from frame to frame. See To batch render IPR files on page 125 for details. It takes longer to perform an IPR render than it does to perform a software render because more information is written to disk. The IPR image contains

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the information needed to perform the shading calculations for each pixel in the image as you adjust scene parameters. When you select a region to adjust, Maya loads all the necessary information into memory for all the pixels in the selected region. As you modify scene attributes, Maya recomputes the shading calculations and the selected region in Render View updates. Since none of the visibility calculations have to be recomputed at this stage, tuning updates much faster than a full software rendering. IPR images can be very large (for example, at NTSC Video resolution, a single IPR image could be up to 60MB). Make sure you have adequate disk space for your IPR image before you perform an IPR Render. NOTE An IPR default light source (created during IPR rendering) works in a similar way to the software renderer’s default light source: ■

The IPR default light source is removed from the scene as soon as the IPR session is terminated (for example, when you click the IPR stop button).

■

The IPR default light source is not saved with the scene, preventing you from accidentally adding the IPR default light to the saved scene.

For more information, see Default lighting in Maya in the Lighting guide.

IPR Limitations (for Maya software renderer) Visibility limitations Any change to an attribute that affects the visibility calculation, such as changing the camera angle, adding or removing a surface, or transforming CVs on a surface, requires another IPR render before you can see the effect of that change. Transformations affect visibility when applied to an object or camera (like moving an object or zooming the view, since moving an object or the camera may change what is visible at each pixel). This does not include lighting changes; they are supported.

Interactive Photorealistic Rendering (IPR) | 49

Adding or removing surfaces, UV mapping values If you add surfaces to or remove surfaces from the scene, or if you change the UV mapping values for a texture, you must perform another IPR render before you see the change. Examples of these kinds of changes include: ■

When you select a new group of faces on a polygonal surface, even if the surface is already in the scene. In IPR, selecting a new group of faces to texture is equivalent to creating a new surface.

■

Turning Fix Texture Warp on/off changes how UV mapping values are generated in an IPR render. This situation is analogous to modifying polygon UVs by changing their placement.

■

Editing UVs in the texture window.

Changing image planes, shadow maps, background color If you make changes to shadow map resolution, image planes, or background color, you must manually update the IPR tuning region (select IPR > Update Shadow Maps or IPR > Update Image Planes/Background).

General limitations for Maya Software Renderer IPR ■

raytracing effects (for example, transparency, reflection, refractions)

■

particles

■

3D motion blur

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anti-aliasing: adaptive shading, multi-pixel filtering

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global override of Enable Depth Maps attribute (in the Render Settings window on page 376) does not function properly

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output to IFF (deep raster)

Mac OS X-specific limitations ■

Cannot render interactively with resolution of 4K or higher

■

If you render an image successfully and then render it again with a lower resolution, the rendered image does not reduce in size.

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Image plane limitations ■

Only supports file mode, not texture mode.

■

Changes to file mode do not IPR render properly unless you turn on “Update Image Planes/Background” per change.

Shader and Texture limitations ■

Use Background shader is not well supported because it relies on raytracing.

■

Modifying, adding, or deleting a displacement map applied to the geometry requires re-rendering.

■

Turning on advanced filters (such as quadratic, cubic, or Gaussian) in the file texture requires re-rendering. Much more information needs to be stored into the IPR image, unless the render was originally generated with the advanced filter turned on.

Geometry changes that require IPR re-rendering ■

Adding or deleting geometry.

■

Transforming or morphing geometry.

■

Changing tessellation.

■

Turning on/off Fix Texture Warp for the surface, or modifying any Fix Texture Warp attributes. TIP Consider using directional lights for preview rendering, especially when using IPR. These lights are easy to transform to get the initial light effect you need. Maya’s default light is the directional light.

Glow limitations ■

Light glow intensity may appear different because the light glow occlusion is computed at the time of the IPR generation. If the light is moved where the light glow occlusion changes, an inaccurate glow intensity could result.

■

Shader glow may look different because the IPR region (not covering the entire scene) produces a different auto-exposure normalization.

Interactive Photorealistic Rendering (IPR) | 51

Others ■

Changing blur-by-frame does not update the IPR unless you re-render.

■

2D motion blur won’t be exactly right because you work on a smaller region.

Render View rendering If you want to render a single frame (or a single frame of an animation), render it in Render View. Advantages include the following: ■

easy to use

■

Maya UI

■

you can see the render as it occurs

■

you can interrupt the render at any time NOTE Large scenes or image files may run out of memory. In this case, use batch rendering to reduce memory usage.

To render in Render View, see: ■

Test render a low-res still or frame on page 127.

■

Render a single frame on page 131.

Batch renders from within Maya (UI) If you want to render an animation, start a batch render from within the Maya UI. (You can also render a single frame this way.) Advantages include the following: ■

easy to use

■

you can continue to use the Maya UI

■

you can start a batch render while you continue to work within Maya

■

you can interrupt the render at any time from within Maya

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To start a batch render from within Maya, see Batch render a still or animation on page 131.

Render from a command line You can render from a command line if you want to render an animation or single frame. Advantages include the following: ■

works with single images and animation

■

uses less memory than having all of Maya (UI) running

■

can be scripted

■

can be integrated into a rendering pipeline (render farms)

■

for Maya software rendering, you can override render settings using command flags (for other renderers, you must also write a MEL script)

For more information, see Command line renderer in the Rendering Utilities guide.

Related topics ■

mental ray for Maya command line options on page 186

Render output File formats Maya can save rendered image files in several standard image file formats. By default, Maya saves rendered image files in the Maya Image File Format (Maya IFF). The Maya IFF is the most efficient format, in which no data loss occurs. All other file formats are translated from the Maya IFF format. For information about the File format syntax, see Subfolders and names of rendered images on page 60. To set the file format, see Set the rendered image file format on page 86.

Render from a command line | 53

Bitmap vs. vector Maya can render and save an image in either bitmap or vector format. A bitmap image uses pixels (colored squares) arranged in a grid to describe the image. When you zoom into a bitmap image, you can see the jagged edges of individual pixels. Common bitmap formats include TIFF, GIF and BMP. A vector image uses vectors (lines and curves) to describe the image. When you zoom into a vector image, lines and curves remain smooth. Common vector formats include SWF (Adobe Flash), AI (Adobe Illustrator) and SVG (Scalable Vector Graphics). NOTE ■

If Image Format is SWF or SVG, an animation renders as a single file. Otherwise, an animation renders as a series of sequential files.

■

EPS files (generated by any application) do not import correctly into non-Adobe products (such as the Flash authoring application). EPS files import correctly into Adobe products. (SWF and AI files import correctly into the Flash authoring application.)

Details of supported file formats Adobe Illustrator (.ai)

This file format is only available on Windows 32-bit and Apple® Mac OS®X, and only when using the Maya Vector renderer. Adobe Illustrator (version 8) file format. When rendering to Adobe Illustrator format, the background color is always white.

Autodesk PIX

This file format is available on Linux® and Windows only. Autodesk pix file format. Maya saves the image, mask, and depth channels as separate files.

AVI (.avi)

This file format is available on Windows only. On Linux, IMF does not support movie files.

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On Windows, you can select the compression method for AVI files. See Compression... on page 380. Microsoft Audio Video Interleaved movie file format. Maya can store a sequence of images in an AVI file. Cineon (.cin)

This file format is available on Linux and Windows. Cineon image file format. Maya does not create a mask file or channel. This is a format typically used for digital film, however, Maya does not use the 10 bit log encoding standard.

Encapsulated PostScript (.eps)

Encapsulated PostScript file format. An EPS file can contain both bitmap and vector image information. When using the Maya Vector renderer (Windows 32-bit and Mac OS X only), the rendered EPS file consists of a vector image. When using bitmap renderers, the rendered EPS file consists of a bitmap image. Maya saves the image and depth channels as separate files. (Maya does not create a mask file or channel.) When rendering to EPS format with the Maya Vector renderer, the background color is always white.

GIF (.gif)

This file format is available on Linux and Windows. Graphics Interchange Format typically used for web. Maya saves the image and depth channels as separate files. (Maya does not create a mask file or channel.) GIF images may be up to 8 bits (256 colors) in depth and are always compressed. Animated GIFs are not supported.

File formats | 55

JPEG (.jpg)

Joint Photographic Experts Group file format. Maya saves the image and depth channels as separate files. (Maya does not create a mask file or channel.) The JPEG format is standard for compressed still images. JPEG uses DCT and offers data compression of between 5 and 100%. Three levels of processing are defined: baseline, extended, and lossless. Maya supports only JPEG formats containing RGB information; Maya does not support JPEG formats containing CMYK information. Compression is controlled by the environment variable AW_JPEG_Q_FACTOR. Setting it to 1 gives the lowest quality (most compression) and setting it to 100 gives the highest quality (least compression). The default value is 75.

Adobe Flash (.swf)

This file format is only available on Windows 32-bit and Mac OS X, and only when using the Maya Vector renderer. Adobe Flash Player (version 3, 4 or 5) file format (non-interactive).

Maya IFF (.iff)

Maya Image File Format with 8 bits per color and mask channel. Additional channels (for example, depth, motion vector data) are stored as floating point data. Maya saves the image, mask, and other channels in one file.

Maya16 IFF (.iff)

Maya Image File Format with 16 bits per color and mask channel. Additional channels (for example, depth, motion vector data) are stored as floating point data. Maya saves the image, mask, and other channels in one file. Not available when using the Maya Vector renderer.

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MacPaint (.pntg)

Mac OS X only.

Adobe® Photoshop® (.ps)

Mac OS X only. Adobe Photoshop file.

PNG (.png)

Mac OS X only.

Quantel (.yuv)

This file format is available on Linux and Windows. Quantel image file format. Maya saves the image and mask channels in one file. The Quantel format outputs to YUV. Maya can only output Quantel format images at NTSC, PAL, or HDTV resolutions; if you select a different resolution, Maya saves rendered images in Maya IFF.

QuickDraw (.pict)

Native Apple® Macintosh® file format.

Apple® QuickTime® Image (.mov)

This file format is available only on Mac OS X. On Mac OS X, all Apple QuickTime image formats are supported, including any userwritten or user-added Apple QuickTime plug-in formats. For the Maya software renderer and the Maya Hardware renderer, Apple QuickTime output supports over 20 different compression codecs for batch rendering and Playblast. Apple QuickTime movie file format. Maya can store a sequence of images in an Apple QuickTime file.

RLA (.rla)

This file format is available on Linux and Windows. Wavefront image file format. Maya saves the image, mask, and depth channels in one file.

File formats | 57

Scalable Vector Graphics (.svg)

This file format is only available on Windows 32-bit and Mac OS X, and only when using the Maya Vector renderer. Scalable Vector Graphics file format. When rendering to SVG format, the background color is always white.

SGI (.sgi)

Silicon Graphics Image file format with 8 bits per color channel. Maya saves the image and mask channels in one file, and the depth channel as a separate file.

SGI16 (.sgi)

This file format is available on Linux and Windows. Not available when using the Maya Vector renderer. Silicon Graphics Image file format with 16 bits per color channel. Maya saves the image and mask channels in one file, and the depth channel as a separate file.

SGI Movie

This file format is only available on and Linux. SGI movie file format. Maya can store a sequence of images in an SGI Movie file. Maya only renders out uncompressed SGI Movie files as these are the most general for reading into other applications.

Avid® Softimage® (.pic)

This file format is available on Linux and Windows. Avid Softimage image file format. Maya saves the image and mask channels in one file, and the depth channel as a separate file.

Targa (.tga)

Targa image file format. Maya saves the image and mask channels in one file, and the depth channel as a separate file. Not all Targa formats are supported.

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Tiff (.tif)

Tagged-Image File Format with 8 bits per color channel. Maya saves the image and mask channels in one file, and the depth channel as a separate file. Maya generates TIFF files that use TIFF 6.0 compression. To generate uncompressed TIFF files, set the environment variable IMF_TIFF_COMPRESSION = none before starting Maya. (For more information on environment variables, see Setting environment variables using Maya.env in the Basics guide.) Use uncompressed TIFF files when you intend to read the images into an application that requires uncompressed images or that supports the TIFF 4.0 standard.

Tiff16 (.tif)

Not available when using the Maya Vector renderer. Tagged-Image File Format with 16 bits per color channel. Maya saves the image and mask channels in one file, and the depth channel as a separate file. Maya generates TIFF files that use TIFF 6.0 compression. To generate uncompressed TIFF files, set the environment variable IMF_TIFF_COMPRESSION = none before starting Maya. Use uncompressed TIFF files when you intend to read the images into an application that requires uncompressed images or that supports the TIFF 4.0 standard.

Windows Bitmap (.bmp)

Windows bitmap image file format. RGB only. Doesn’t support paletted images. Maya saves the image and depth channels as separate files. (Maya does not create a mask file or channel.)

HDR (.hdr)

High dynamic range images. Render HDR images when using the mental ray for Maya renderer.

File formats | 59

Subfolders and names of rendered images

You can create subfolders as well as custom filenames for storing your rendered images using the File Output section in the Render Settings: Common tab on page 377. This section describes the tokens that you can input to create the subfolders and filenames. Should you decide not to input any of the tokens described below, Maya creates default subfolders in which it saves the rendered images. For more information regarding project file locations, see File > Project > New of the Basics guide.

Default behavior of rendered images and directories By default, Maya saves rendered images to the following subfolders: /

Scenes with more than one render layer and renderable camera If your scene consists of more than one render layer, then a subfolder is created for each layer. Similarly, if your scene consists of more than one renderable camera, a subfolder will be created for each camera. For example, a scene with two render layers and two renderable cameras would save out rendered images to subdirectories as follows: layer1/camera1/ layer1/camera2/ layer2/camera1/ layer2/camera2/

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Scenes with only one render layer or only one renderable camera By default, a layer subfolder is not created for a scene with only one render layer. Therefore, a scene with two renderable cameras but only one render layer creates subfolders as follows: camera1/ camera2/

Similarly, a camera subfolder is not created by default for a scene with only one renderable camera. Therefore, a scene with two render layers but only one renderable camera creates subfolders as follows: layer1/ layer2/

If a scene has only one render layer (or no layers at all) and only one renderable camera, then subfolders are not created by default and Maya saves the scene as MyScene.iff. NOTE Explicitly entering tokens forces folders to be created. See Rendered image filename options (tokens) on page 61 below for more information.

Creating subfolders and filenames for rendered images The following rendered image filename options and tokens can be combined to create subfolders and custom image names for rendered images. Enter these options in the File Name Prefix field of the Render Settings: Common tab on page 377. Use the tokens in conjunction with different separators between them. To create subfolders, use the slash (/) separator as in //. Use any other separator, for example, underscore (_) and dash (-), to separate the tokens in your image file name. You can repeat options within the specification, and you can also specify any text you like in the image file name or path (for example, .TEST or _final to indicate the kind of render that you are performing).

Rendered image filename options (tokens) Adds the layer name to the created subfolder or image file name (for example, layer1). When using render passes with the Maya software renderer, if more than one pass is created for the layer, then pass names are appended to the layer name.

Subfolders and names of rendered images | 61

The format used is layer_pass (for example, layer1_beauty). For more information on passes, see Render passes on page 301. When using multi-render passes with the mental ray renderer, a directory is created for each pass. See Multi-render passes on page 187for more information. Adds the scene name to your subfolder or image file name. Adds the renderable camera name to the created subfolder or image file name (for example, camera1). If your scene is set to render fields, then field names are appended to the name; for example, camera_odd or camera_even. Adds the render pass file group name to the created subfolder or image file name (for example, IndirectIllum). See Pass Group Name on page 501 for more information regarding the pass group name. Add the render pass node name to the created subfolder or image file name(for example, diffuseNoShadow). Many different types of render passes are available for selection using the Render pass Attribute Editor on page 501, for example, beauty, shadow, specular, refraction, and so forth. When you use this render token, a unique abbreviation of the pass type, of less than 6 characters, is appended to your output file name, for example, REFR for refraction pass. Adds the extension to the created subfolder or image file name. Adds the version label that you have selected to the created subfolder or image file name. This option can be a numeric version number, the current date, the current time, or any custom version label. Customize this token using the Version Label attribute. NOTE For more information regarding render tokens, see Render Settings: Common tab on page 377.

OpenEXR file format Among the available multi-channel file formats, OpenEXR is the only file format where multi-channel is being leveraged. Therefore, multiple render passes can be concatenated into a single-multi-channel .exr file. Use the Frame Buffer Naming and Custom Naming String attributes in the Render Settings: Common tab on page 377 to customize the naming of your OpenEXR channels. In order to use these attributes, your scene must contain at least one render pass. Also, you must select OpenEXR as your file format for these attributes to become active.

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Select the Automatic mode under the Frame Buffer Naming attribute to use the :. tokens to name your channels. This is the default option. Select the Custom mode under the Frame Buffer Naming attribute to customize your OpenEXR channel names. Choose from the render tokens listed in Rendered image filename options (tokens). Your frame buffer name must be less than or equal to 31 characters in length; otherwise, the name is truncated and a warning appears. NOTE The OpenEXR filename has a 31 character limit. If your filename exceeds this limit, it is truncated automatically. Therefore, when taking advantage of the multi-channel capabilities of OpenEXR, you should keep the render pass name and camera names as short as possible to avoid automatic truncation of the filename. NOTE Do not use the token in your File name prefix field if you are using the multi-channel OpenEXR format. Using the token creates a file for each render pass instead of writing to a multi-channel .exr file. See Render Settings: Common tab on page 377 for more information.

Frame/Animation Ext In addition to the rendered image filename tokens discussed above, you can also use the Frame/Animation Ext drop-down list to customize your image name by adding the frame number to your image name. For example, if you choose name#.ext with a Frame padding of 4, and the scene name is MyScene, then the rendered image would be named MyScene0001.iff.

Examples 1 If you choose not to enter any tokens in the File Name Prefix attribute, the following subfolders are created by default: //IMAGENAME.iff

2 If you choose to use the Frame/Animation Ext field in conjunction with the File name prefix on page 377 attribute, you can add the frame number to your image name also. Assume that you choose the name_#.ext option with a Frame padding of 2. The following entry produces a layer name subfolder and adds 1) the camera name, 2) the scene name, and 3) the frame number to the name of the rendered image. The -(dash) separator is added to separate the camera and scene names.

Subfolders and names of rendered images | 63

/-

For example, layer1/camera1-MyScene_01.iff 3 The following entry produces no subdirectories, but simply a flat file structure. The _(underscore) separator separates the scene, layer and camera names. __

For example, MyScene_layer1_camera2_01.iff 4 The following entry produces a scene name subdirectory, then the layer subdirectory, then a camera subdirectory, and then adds the scene name to the name of the rendered image, and adds ‘TEMP’ to the image name: ///TEMP

for example, MyScene/layer1/camera1/MySceneTEMP_01.iff

File output location By default, Maya saves rendered images to the images directory of the current project. You can, however, change the location to save in any directory. To set the file output location, see Set rendered images output location on page 88. NOTE If you are rendering images with a mask or depth channel and the file format of rendered images does not support mask or depth channels, Maya may save the mask channel as a separate file in the mask directory of the current project, and the depth channel as a separate file in the depth directory of the current project. The IFF and RLA file formats can hold mask and depth channel information. For more information regarding the treatment of mask and depth channels by various file formats, see Details of supported file formats on page 54.

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Pixel aspect ratio A rendered bitmapped image file consists of numerous rectangular pixels (picture elements). The size of a rendered image is measured by the number of pixels it contains horizontally and vertically, and by the aspect ratio of individual pixels (whether pixels are square or rectangular). Most display devices (for example, a computer monitor) have square pixels, and their Pixel Aspect Ratio is 1. Some devices, however, have non-square pixels (for example, NTSC video has a Pixel Aspect Ratio of 0.9). To set the pixel aspect ratio, see Set the resolution and pixel aspect ratio on page 88.

Resolution Image resolution is the total pixel size of a bitmap image. For example, 720 x 486 for NTSC video output. Display resolution is the number of pixels in 1 inch on the screen. Display resolution is measured in pixels per inch (ppi). Most monitors have a display resolution of about 72 ppi. If your output is for print, consider a display resolution of around 300 ppi. To set the pixel aspect ratio, see Set the resolution and pixel aspect ratio on page 88. NOTE The terms pixels per inch (ppi), and dots per inch (dpi) are often interchanged freely. Pixels per inch, however, applies only to screen resolution, which display images in pixels. Dots per inch, applies only to paper-based images, which are printed with dots of color.

Frames vs. Fields Only the Maya software renderer supports field rendering. Motion picture film and video simulate motion by displaying a continuous sequence of images or frames. There are, however, important differences in the way film and video systems display individual frames which may affect how you render images. To render as frames or fields, see Specify frame or field rendering on page 91.

Pixel aspect ratio | 65

Video system fields Most video systems display an individual frame in two stages—by illuminating half of the phosphors on a television screen (in NTSC every odd row beginning with the first row), and then illuminating the remaining half of the phosphors (every even row beginning with the second row). These two half-frames are known as fields and the process of displaying the two fields alternately is called interlacing.

NTSC and PAL video systems both use interlaced fields. NTSC video systems display 30 frames per second, or 60 fields per second; PAL video systems display 25 frames per second, or 50 fields per second. Because video systems display an individual frame in two stages, if you render images as frames (that is, in one stage) and then display them on a video system, fast moving objects may appear jerky or choppy. If post-production process or final presentation formats involve interlaced video systems, render images as fields. (If your animation does not contain fast moving objects, you could try rendering images as frames.) To properly view a frame or an animation rendered as fields, you must interlace the two fields together.

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Motion picture film frames Motion picture film projectors display an entire frame in one brief instant by shining light through the film. Most motion picture film systems display 24 or 25 frames per second. If your post-production process and final presentation format do not involve interlaced video systems, render images as frames.

Color, Depth, and Mask (alpha) channels

Each pixel in a bitmap image contains three color channels, each of which represent the amount of red, green, or blue in the image. Each pixel might also have an alpha (mask) channel to achieve transparency and a depth channel that represents the distance from the camera. By default, Maya generates an image file with three color channels and a mask channel. To enable specific channels to rendered images, see Enable color, depth, and mask channels for rendered images on page 89. NOTE Mask channels and depth channels are mainly used for compositing, so if you don’t plan on compositing rendered images, you don’t have to generate mask or depth channels (or files) during rendering. The file size increases if an image contains a mask or depth channel. The computation time may also increase. For information about mask and depth channels and files, see Mask and depth channels on page 78.

Color, Depth, and Mask (alpha) channels | 67

Pre Render MEL and Post Render MEL scripts In some situations, you may want Maya to run a specific MEL command or script before rendering each frame, and another MEL command or script after rendering. For instance, if your scene contains a very large complex surface, which you do not want to work on, you could run a MEL command before rendering to display the surface (so it renders), and run another MEL command after rendering to hide the surface. To run Pre Render MEL scripts or Post Render MEL scripts, see Run Pre Render MEL or Post Render MEL scripts on page 92. NOTE If you need to use multiple sets of quotations in the preframe MEL or post frame MEL fields in Render Settings window, be sure to use \" for every quotation mark except the first and last. For example, print("Time to render my Maya scene, called\"bingo.mb"\");

Layers and passes Render layer overview

A system of per layer and per object overrides means that objects can have different shading and rendering attributes on different layers. With render layers, you can assign any object to multiple layers with a different material on each layer. This lets you create multiple images for each frame, from any combination of Maya's four renderers, third party plug-in renderers, and post- processes such as Fur and Paint Effects. Rendered images can be efficiently organized for output to a compositor. Render layers can be also be rendered to Adobe® Photoshop® (PSD) format, which supports multiple image layers. As well, a preview composite of all the layers can be viewed in the Render View.

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Benefits of render layers You can propagate changes across layers that exist in a single scene, rather than having to manage multiple scenes. Render layer presets allow easy setup of commonly-used passes, such as shadows and specularity. Render Layers can also be used to prepare different layers in a scene for vertex baking or light mapping.

Overview of render layer workflow

Examples of how layers are used: ■

Working with render layers: different layer examples on page 71

Render layer overview | 69

Related topics ■

Render layer concepts on page 73

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Work with layers on page 100

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Work with layer overrides on page 102

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Work with attribute overrides on page 109

Overview of render layer preview workflow

The Master layer is non-renderable by default (this is only relevant if there is more than one layer). To set whether a particular layer is renderable, click the R to the left of the layer name.

Related topics ■

Preview layers on page 111

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Render layers to PSD format on page 115

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Batch and command-line render with layers on page 116

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Working with render layers: different layer examples You can segment your scene using render layers. If you have foreground, midground, and background objects in your scene, you can render them using three different layers. This can save a lot of time when rendering if there is no interaction between the objects; for example, in a forest scene, you would render three different layers separately: a static background (sky, trees), midground (a cottage), and foreground (characters). Rendering the static background once and then compositing later can speed up your workflow and render time dramatically. A more complex example might involve different effects that you want to composite. One layer has raytracing turned on just for those objects that need it (raytracing can be a very time-consuming process). A second layer has glow lights which will be composited with certain objects to produce halo effects; and a third and fourth have the shadow and specular information for later compositing. Consider the following example of two planes in a dogfight.

This image is made up of five composited layers that are rendered separately. The background is one layer, as is the foreground airplane and the midground airplane.

Working with render layers: different layer examples | 71

The two other layers are for effects: the midground bullets with their glow and blur are rendered on a separate layer, as are the motion-blurred propellers.

All these layers are composited together with different blend modes in order to create the final image you see here. This simplifies the workflow and makes it easy to re-render parts of the scene with different options. A larger production may use different renderers for different passes as well as modifications to lights, objects, and layer overrides. For example: ■

A Beauty layer rendered in the Maya software renderer using production quality.

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A Matte layer rendered with Maya hardware renderer; this could be lower quality as only the alpha channel matters. Hardware particle effects could be rendered on this layer as well.

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A Reflection layer rendered in mental ray using bright white lights. If there weren’t reflections in all parts of the scene, this could be only rendered for part of the scene (for example, only the middle 100 frames).

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A Glow layer rendered in the Maya software renderer for glowing objects. It can be rendered extra bright knowing it will be dialed down as needed in the compositor.

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A “Hot” layer rendered with mental ray (for example, an exaggerated specular achieved by assigning white Blinn to all objects, tweaking the specularity, and setting key lights bright and slightly red).

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A “Cool” layer rendered with mental ray final gather and no other lights. As well, an exaggerated diffuse is rendered from this layer, achieved by assigning a white Lambert to all objects and tweaking the diffuse).

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A Dirt layer as an ambient occlusion pass rendered by mental ray.

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Render post processes like Fur and Paint Effects are also rendered separately.

Render layer concepts

The following section describes basic concepts necessary to work with render layers: ■

Master layers and layer membership on page 74

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Changes to a layer or to objects on a layer (overrides) on page 74

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Master layer and render settings on page 75

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Viewing layers and managing layers on page 75

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What you can do with render layers: summary on page 76

Render layer concepts | 73

Master layers and layer membership The Master layer contains all the objects and materials in the scene. There is always a Master layer in your scene; it’s exposed in the Render Layer editor. It is only visible in the Render Layer editor if there is more than one layer (in which case it is non-renderable by default). When you create new layers, you can make any objects or nodes (including lights) members of only that layer, multiple layers, or all layers. Only objects in a specific layer affect or contribute to that layer; this includes lights, reflections, shadows, and so on. In addition to segmenting your scene into render layers, you can change the characteristics of each layer or object on a layer by creating layer overrides. (By definition, you can't override the characteristics of the Master layer.) Maya stores each of the layer and attribute overrides as changes between that layer and the Master layer. See the next section.

Changes to a layer or to objects on a layer (overrides) There are two types of overrides for attributes: per layer and per object. ■

Per layer overrides change attributes, characteristics, or material assignments that affect the entire layer. This can include the renderer for the layer, the image size for the rendered image of that layer, whether or not all objects on the layer cast shadows or receive shadows, or a material assigned to all objects in the layer.

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Per object overrides change the value of an attribute or material assignment on an object in a specific layer on which overrides exist. This can include the material assignment for an object on the layer, render stats for that object (such as casting or receiving shadows), or attributes of the object, or on per-object shaders (such as transparency).

There are two ways to create overrides: auto and manual. ■

Auto overrides immediately change the value of the attribute to be different than the one specified on the Master layer, without any additional action required on your part.

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Manual overrides require you to explicitly tell Maya that you want that attribute value to be different than the one specified on the Master layer. ■

Per layer auto-overrides include shader assignments (to all objects in a layer); see Work with layer overrides on page 102.

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Per layer manual overrides include changes to per-layer render settings and member overrides (render stats). See Work with layer overrides on page 102.

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Per object auto-overrides include material assignments to objects; see Work with attribute overrides on page 109.

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Per object manual overrides include all other attribute change; see Work with attribute overrides on page 109.

Master layer and render settings To facilitate changing the Master layer’s render settings (the base from which all overrides are created), the Render Settings for the Master layer shows the renderer-specific tabs for all four renderers: Maya Software, Maya Hardware, Maya Vector, and the five mental ray renderer tabs.

Changing the settings on the Master layer means that all layers that use that renderer and do not have overridden attributes inherit these settings.

Viewing layers and managing layers Render layers affect the scene view, Hypergraph, Hypershade, and so on. Switching layers means that lights, geometry, or nodes are visible or not depending on whether those objects are in a particular render layer. (Previously, objects always appeared in the scene view and were either present or not present in a render.) Visibility of Display layers and Render layers interact subtractively. That is, if you have a Display layer that contains objects and turn off visibility on that layer, you will also not see these objects in any of your Render layers. ■

There are three different ways to create per-layer changes: ■

overrides that affect the entire layer

Render layer concepts | 75

■

■

auto-overrides to render stats or material assignment of an object on a layer

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manual overrides to any other attribute .

There are three different ways to create per-layer changes: ■

overrides that affect the entire layer

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auto-overrides to render stats or material assignment of an object on a layer

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manual overrides to any other attribute .

What you can do with render layers: summary Once you understand the basic concepts of Master layer, layer and object overrides (auto or manual), render settings, and presets, you can do the following on a layer-by-layer basis: ■

select the renderer (software, hardware, mental ray, vector, and any plug-in renderer) and override Render Settings (formerly known as Render Globals) both in the Common tab and in the renderer-specific tab.

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create layer overrides. You can override settings that affect rendering; for example, you can turn off Cast Shadows and turn on Visible in Refractions and Visible in Reflections for a layer.

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override material assignments: ■

per component (for example, assign certain faces a different material for any layer).

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per object (for example, assign certain surfaces a different material for any layer)

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override any renderable attribute (for example, set a different value for transparency on a object on a particular layer)

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assign the blending modes for layers directly in the Render layer editor, and preview the layer composite in the Render View.

For examples of how to use layers, see: ■

Working with render layers: different layer examples on page 71

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■

Render layers example: automotive preview on page 298

Related topics ■

Work with layers on page 100

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Work with layer overrides on page 102

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Work with layer presets on page 294

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Work with attribute overrides on page 109

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Preview layers on page 111

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Control visibility/reflection per layer on page 120

You can render individual objects, groups of objects on layers, or attributes (passes) of your scene, then combine them using a compositing system. Compositing is the process of combining multiple images into one. (You can also render global illumination passes separately. To set up layers and passes, see Render layer overview on page 68 and Render passes on page 301.

Advantages of rendering in layers and passes Rendering separate objects in layers and passes takes more time and effort to plan, but it offers the following advantages: ■

More creative freedom. For example, you can render different layers with different render options. You can then color correct or add special effects to each rendered layer in a compositing application.

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Flexibility to accommodate unanticipated requests for changes. For example, you can change a ceramic vase to a glass vase without re-rendering the entire scene.

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Increased speed to meet production schedules. For example, you can quickly render the foreground layer where most changes occur, instead of the whole scene or background, where objects tend to be static. You can also render smaller portions of large scenes, reducing the load on computer memory.

Render layer concepts | 77

General tips for rendering for compositing ■

Plan to separate a scene into elements early in the production process.

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If you plan on compositing rendered images, make sure the scene’s background is black. To change the color of the background, see the Lights and camera’s chapter.

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Understand the type of image that compositors require: premultiplied or not.

Premultiplied images When an image is stored not only with the three basic color channels but also with the alpha channel, the presence of the alpha channel can modify the color channels to some degree. For example, typically the color channels have been multiplied by the value of the alpha channel to take transparency into consideration. Some compositors (as well as games engines) can use premultiplied images; others require separate image and alpha information, especially when they want to separate object color data from background color data. By default, Maya premultiplies images, but you can turn premultiplication off. To turn premultiplication on or off, see Premultiply on page 398.

Mask and depth channels During rendering, Maya software can generate an image file that contains color channels (RGB), a mask channel (RGBA), a depth channel (RGBZ) or a combination of the three (RGBAZ). For more information on color channels, see Color, Depth, and Mask (alpha) channels on page 67.

Some image formats cannot include embedded mask or depth channels; in these cases, Maya can generate a separate mask or depth file.

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By default, Maya generates an image file with three color channels and a mask channel. Mask channels and depth channels are mainly used for compositing. You can control the types of channels Maya includes in rendered image files. For instance, if you don’t plan on compositing rendered images, you don’t have to generate mask or depth channels during rendering. To turn channels on or off, see Enable color, depth, and mask channels for rendered images on page 89.

Mask channels A mask channel (or alpha channel) defines where an image is opaque or transparent. Opaque regions of the objects are white, semi-transparent regions are gray, and transparent regions are black. Use a mask channel to layer images for compositing software. For instance, you can use the mask channel of an image as a matte to composite an object (without its background) with another image.

Depth channels A depth channel (or Z depth or Z buffer channel) provides 3D information about an image. It represents the distance of objects from the camera. Depth channels are used by compositing software. For instance, you can use the depth channel to correctly composite several layers while respecting the proper occlusions. Maya stores depth values as -1/z. These represent the near and far clipping values.

Arranging objects in order in 3D space When you render in layers the compositing application must be able to tell which part of which object goes behind or in front of another one. Alpha channels do not contain this information, so you can use the Black Hole mode of the Matte Opacity feature in Maya to produce cutout regions that composite correctly. See Modify a mask channel on page 90. To set up layers and passes, see Render layer overview on page 68 and Render passes on page 301.

Mask and depth channels | 79

Render passes

To render various attributes separately, for example, color, shadow, specular shading, and so forth, you may want to use render passes. If you are using the Maya software renderer, see Render passes on page 301for more information. If you are using the mental ray renderer, see Creating a pass-compliant shader using the AdskShaderSDK and Sample workflow for multi-render passes on page 224for more information.

Compositing Interoperability Plug-in Compositing Interoperability Plug-in for Toxik The Compositing Interoperability plug-in allows you to export information from your Maya scene to Autodesk Toxik. Load this plug-in through the Maya Plug-in Manager (see Plug-in Manager). When you load the plug-in, a Toxik-specific menu item appears in the Maya Render menu. Using this plug-in, you can generate a preliminary Toxik composition from within Maya based on the render layers in your scene. The compositing graph includes the associated image sequence filenames, Maya blend modes, and layer-specific render settings.You can export all the layers in your scene, or selected layers. This plug-in architecture can be used to implement integrations to your preferred compositing application. For more information, see the compositingInterop command.

Related topics ■

Work with Autodesk Toxik 2007 on page 135

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Work with Autodesk Toxik 2008 on page 139

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Render > Export All Layers to Toxik 2007 on page 334

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Render > Export Selected Layers to Toxik 2007 on page 335

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Render > Export to Toxik 2008 on page 336

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Render tiles in the Maya Software renderer Render tiles The Maya Software renderer renders an image as a series of tiles. The renderer tries to use a tiling configuration that ensures memory is optimized. Thus, the tiles are smaller in the regions of the image where the geometry is dense. The renderer tries to ensure that the memory cap specified in Render Settings window is respected. See also Troubleshoot render tiles on page 149.

Visualize scenes and render images A typical rendering workflow The exact workflow steps and the order in which you perform them vary. Rendering is an iterative process in which you tweak lights, textures, and cameras; adjust various scene and object settings; visualize your changes; then, when you are satisfied with the results, you render your final images. Once you have completed shading and texturing objects, adding lights, and adding renderable cameras to your scene, you can render your scene. The following workflow outlines the typical steps.

Related topics ■

Surface shading in the Shading guide.

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Light and shadow in the real world in the Lighting guide.

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Viewing cameras vs. rendering cameras on page 13.

To render a scene 1 Decide which renderer you want to use, and set scene options for it: ■

For detailed information about each of Maya’s renderers, see Maya Software renderer on page 4, Maya Hardware renderer on page 5,

Render tiles in the Maya Software renderer | 81

Maya Vector renderer on page 8, mental ray for Maya renderer on page 11. ■

To select a renderer, see Select a renderer on page 11.

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To learn more about some of the scene options you can set, see Open the Render Settings window on page 84. For detailed descriptions of the scene options, see Render Settings window on page 376.

2 If you plan to composite your work, you can render your scene in layers and passes. See Render layer overview on page 68 and Render passes on page 80. 3 Make any required per-object adjustments: ■

To adjust the surface quality (tessellation) of objects, see Adjust NURBS tessellation settings on page 42, Adjust polygonal tessellation on page 44, or Adjust subdivision surface tessellation on page 45.

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To adjust per-object settings; for example, settings for lights, cameras, objects, see information on the particular object you want to adjust.

4 Test iterations of your scene to visualize your the changes you make materials, textures, lights, cameras, and objects. ■

To visualize your changes as you make them, see Visualize interactively with IPR on page 123.

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To diagnose scene problems, see Run diagnostics on page 166.

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To optimize rendering speed image quality, see The speed/quality tradeoff on page 153.

5 When you are satisfied with the results, render the final images. ■

See Render a single frame on page 131.

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See Command line rendering on page 133. NOTE When working on the Linux platform and rendering with the Maya Software renderer, you may choose to send the (rendering) output messages to a file instead of to the shell. Use the command maya >& logfile. A file with the name logfile is created and all output messages are saved to this file upon rendering in Maya.

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Choose a rendering method TIP Before you render a scene, you should diagnose it for common problems which can affect image quality and rendering times. See Diagnose scene problems on page 166.

Visualize a scene Though you can render a scene to see what it looks like, visualizing your scene in the following ways can be faster: To...

Do this...

See changes to a still image or a single frame of an animation as you make them.

Use Interactive Photorealistic Rendering (IPR)IPR updates the display to show your most recent change, but there are limitations to what you can see. For more information, see Interactive Photorealistic Rendering (IPR) on page 47.

See what a still image or single frame of an animation (or a region of it) looks like as the render occurs.

Use Render View, especially Render Region.Render View has fewer limitations than IPR, so you can see more, but it takes longer to render.Render regions of a scene to reduce the amount of time you spend visualizing the scene. For more information, see Render View rendering on page 52.

See lights, objects and textures in the scene view without rendering.

Use hardware texturing.This does not actually perform a render; it just lets you see an approximation of what your scene looks like when rendered. For more information, see See shading and lights in a scene view on page 126.

See what a fully rendered still image, single frame of an animation, or an animation looks like quickly.

Render at lower resolutionsFor more information, see Test render a low-res still or frame on page 127 and Test render a lowres animation on page 128.

Choose a rendering method | 83

Perform a final render To render...

Do this...

A still image or single frame of an animation.

Use Render View.For more information, see Render a single frame on page 131.

A still image or single frame of an animation, or an animation.

Batch render.For more information, see Batch render a still or animation on page 131.

A still image or single frame of an animation, or an animation.

Command line render.For more information, see Command line rendering on page 133.

Set scene options Open the Render Settings window The settings you use to produce your final rendered image or sequence of images depend on a number of factors, including: ■

the renderer you use

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the medium to which you are outputting

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whether you are rendering in layers and passes for compositing

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whether you are preview rendering or producing the final rendered image(s) NOTE The changes you make in the Render Settings window affect the entire scene. Often, it makes sense to adjust settings on a per-object setting.

Render settings for the Hardware renderer, the mental ray for Maya renderer, the Maya software renderer, the Maya Vector renderer are available from the Render Settings window. The Common tab of the Render Settings window contains the attributes common to most of the renderers, which decreases the number of parameters

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you need to modify when switching between renderers. Settings specific to the chosen renderer are available in a another tab. For detailed descriptions of the settings in the Render Settings window, see Render Settings window on page 376. To open the Render Settings window 1 Do one of the following: ■

Click Window > Rendering Editors > Render Settings.

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Click the Display Render Settings Window button on the main toolbar or in Render View.

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Select Options > Render Settings in Render View.

You can edit settings in the Common tab and the renderer-specific tab. For more information, see Render Settings window on page 376.

Render all or some objects from a camera By default, your scene has only one renderable camera (the original perspective camera) that renders all objects in your scene. You can change this to render only selected objects in your scene. If you add another camera to your scene and want to make it renderable (or you would like to make one of the default orthographic cameras renderable), you must set this camera to renderable (see Make an existing camera renderable on page 23). To render only selected objects in your scene 1 Select the objects you want to render. 2 In the File Output section of the Render Settings window on page 376, select the camera from the Renderable Camera drop-down list. 3 In the Render View window, select Render>Render Selected Objects Only. 4 Render the scene.

Set scene options | 85

Set the rendered image file format Maya can save rendered image files in one of several standard image file formats. By default, Maya saves rendered image files in the Maya Image File Format (Maya IFF). For a comprehensive list of supported file formats, see File formats on page 53. NOTE For image formats that cannot include mask or depth channels, Maya generates a separate mask or depth file. To set the file format of rendered images 1 In the File Output section of the Render Settings window on page 376, select the Image Format from the drop-down list.

Set file name syntax For information on the file name syntax, see Subfolders and names of rendered images on page 60. NOTE You can also set the file name of rendered files when you render from a shell or command line, using Render and the -im option. See Render from a command line on page 53 for information about command line rendering. To set the file name (syntax) for rendered images 1 In the File Output section of the Render Settings window on page 376, set the following: ■

File name prefix, (for example, rocket): Option

Example

name

rocket

name.ext

rocket.iff

name.#.ext

rocket.1.iff

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Option

Example

name.ext.#

rocket.iff.1

name.#

rocket.1

name#.ext

rocket1.iff

IMPORTANT ■

If you select an option that does not contain #, Maya renders a single frame.

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If you select an option that does contain #, Maya renders an image sequence (animation). The top of the Render Settings window on page 376 provides feedback for the output files.

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Frame/Animation Ext to the combination and order of base name (name).

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File format extension (ext).

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Frame number extension (#) you want rendered files to have.

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Start Frame to the first frame you want to render and End Frame to the last frame you want to render.

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By Frame to the increment between frames you want to render.

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Frame Padding to the number of digits you want in frame number extensions.

To use a custom file format extension for rendered images 1 The file format extension is the standard file format extension for the current Image Format setting. To change that, in the File Output section of the Render Settings window on page 376, turn on Use Custom Extension and type the extension you want to use.

Set scene options | 87

Set rendered images output location For information on image file location, see File output location on page 64. To set the location where rendered images are saved 1 From the main Maya window, select File > Project > Edit Current. 2 In the Project Data Locations section of the Edit Project window, change the directory for Images and click Accept. TIP You can also set the location where rendered files are saved when you render from a shell or command line using Render and the -rd option. See Render from a command line on page 53 for information about command line rendering.

Set the resolution and pixel aspect ratio You can select from a list of preset render resolutions, or set the resolution options manually. For details on resolution, see Resolution on page 65. For details on pixel aspect ratio, see Pixel aspect ratio on page 65. To set the resolution and pixel aspect ratio of rendered images 1 In the Image Size section of the Render Settings window on page 376, select a preset render resolution from the Presets attribute(for example, 640 x 480). If you do not see an appropriate preset Render Resolution, you must set the following attributes manually to output to an unlisted device: ■

Width, Height

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Pixel Aspect Ratio

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Enable color, depth, and mask channels for rendered images Color channels, depth and mask channels are generated by default. Each pixel in an image may consist of channels representing the amount of red, green, and blue, mask, depth in the image. If channels have been turned off, you can turn them back on. For more information about mask channels, see Mask and depth channels on page 78. NOTE During bump or displacement mapping, if an image file contains a mask channel, the mask channel is used for displacement and bump mapping. If the mask channel is absent, the luminance of the RGB is used to displace and, or bump map. If you prefer to use the luminance information as the alpha, turn on the Alpha Is Luminance attribute (in the Color Balance section of the file texture’s Attribute Editor). To enable a channel to rendered images 1 In the File Output section of the Render Settings window on page 376, select the camera from which you want to render from the Renderable Camera drop-down list. 2 Do any of the following: ■

Turn on RBG Channel (Color)

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Turn on Alpha Channel (Mask)

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Turn on Depth Channel (Z Depth)

Create and view depth files The depth channel represents the distance of objects from the camera. To create a Depth file 1 Turn on Depth Channel (Z Depth) in the Render Settings window on page 376.

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2 Open the renderable camera’s Attribute Editor in which you want to create a depth file. Select View > Camera Attribute Editor... from the current view. See View > Camera Attribute Editor on page 345. 3 In the camera’s Attribute Editor, select a Depth Type from the Output Settings section (Closest or Furthest Visible Depth). To view depth channels 1 View the animation file using FCheck. See the Overview of FCheck in the Rendering Utilities guide for information on FCheck. ■

IRIX, Linux and Windows

2 Press z to see the depth channel. ■

Mac OS X

FCheck does not let you view the z-depth data of an .IFF file. To view z-depth data, use a non .IFF file format and then view the z-depth data stored in the separate file. If the output format is not IFF or RLA, Maya writes a separate depth file containing a black RGBA image with depth values.

Modify a mask channel For Maya software and mental ray for Maya. To increase or decrease the mask value for an object 1 In the Matte Opacity section of an object’s material Attribute Editor, set Matte Opacity Mode to Opacity Gain and adjust the Matte Opacity value. During rendering, Maya first generates the mask channel, then multiplies the mask values for the object by the Matte Opacity value. For example, if Matte Opacity is 1, the mask values for the object remains unchanged; if Matte Opacity is 0.5, the mask values for the object are half their original values.

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To set the mask value for an object to a constant value 1 In the Matte Opacity section of an object’s material Attribute Editor, set Matte Opacity Mode to Solid Matte and adjust the Matte Opacity value. If the object is transparent, any objects behind it appear in the mask channel. During rendering, Maya first generates the mask channel, then sets the mask values for the object to the Matte Opacity value. For example, if Matte Opacity is 1, the mask values for the object are 1; if Matte Opacity is 0.5, the mask values for the object are 0.5. To set the mask value for an object to zero 1 In the Matte Opacity section of an object’s materials Attribute Editor, set Matte Opacity Mode to Black Hole. During rendering, Maya first generates the mask channel, then sets the mask values for the object to 0. If the object is transparent, any objects behind it will not appear in the mask channel.

Specify frame or field rendering Motion picture film and video simulate motion by displaying a continuous sequence of images or frames. When you render images as frames, Maya generates one image file for each time frame of an animation. By default, Maya renders images as frames. When you render images as fields, Maya generates two image files for each time frame of an animation, one for each field. Maya renders a frame at time “x” by rendering one field at time “x” and one field at time “x+0.5”. For information on the differences between film and video systems see, Frames vs. Fields on page 65. To properly view a frame or an animation rendered as fields, you must interlace the two fields together. TIP The settings you use for rendering images as fields may depend on the video standard you are using for the images, and how fields interlace together (for example, NTSC or PAL). Before you render an animation as fields, perform a test render and use the test rendered images through your entire post-production process.

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To render images as fields for Maya software rendering 1 Choose the Field option from the Maya Render Settings window on page 376. Interlacing is automatic. To render images as fields for anything other Maya software rendering 1 In the Render Settings window on page 376, set the By Frame value to 0.5. This results in twice as many frames being rendered. 2 Turn on the Renumber Frames Using option and set Start Number and By Frame values to 1. 3 Interlace the resulting images using a third-party solution. To interlace two fields together on Linux 1 See interlace in the Rendering utilities guide.

Run Pre Render MEL or Post Render MEL scripts IMPORTANT When you render a scene from within Maya, make sure you do not specify a MEL command or script that includes delete operations or you may accidently delete objects in your scene. To run a MEL command or script before or after rendering 1 In the Render Options section of the Render Settings window on page 376: ■

Enter a MEL command or execute a script to run before rendering each frame in the Pre Render MEL attribute box.

■

Enter a MEL command or execute a script to run after rendering each frame in the Post Render MEL attribute box.

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Adjust anti-aliasing NOTE You may not need to adjust quality settings for an entire scene. Adjusting settings on a per-object basis is often more efficient and has less of an impact on rendering speed. For more information on aliasing artifacts and strategies on how to fix them, see Anti-aliasing and flicker on page 154.

Maya software rendering specifics The options in the Presets drop-down list and the Edge Anti-Aliasing Quality drop-down list drive each other; when you change one, the other changes, and values for the Anti-aliasing subsections are automatically filled in. You can fine tune any of these settings. Do one of the following: ■

In the Anti-Aliasing Quality section of the Render Settings window on page 376, select a preset.

■

In the Anti-Aliasing Quality section of the Render Settings window on page 376, select Custom, then manually adjust the settings in Number of Samples, Multi-pixel Filtering, and Contrast Threshold.

Maya Hardware rendering specifics The options in the Presets drop-down list drive values for other settings in the Quality section of the Render Settings window on page 376. You can fine tune any of these settings. Do one of the following: ■

In the Quality section of the Render Settings window on page 376, select a preset.

■

In the Quality section of the Render Settings window on page 376, select adjust any of the settings in the section.

Related topics ■

mental ray anti-aliasing specifics on page 238

Set scene options | 93

Adjust output image filtering TIP ■

In most cases, you should test render a file texture in Render View when filtering because you may not be able to see the results in the views or in Attribute Editor swatches.

■

When bump mapping, set Filter to a low value (under 0.1). Filter is primarily used for anti-aliasing textures—distant surfaces are blurrier. This may cause a bump map to become smoother when further away. If you want the bumps to be smooth, use a small Filter Offset value for a constant blur.

To fix a noisy procedural texture that appears to shift and swim during an animation 1 Do any of the following: ■

Increase the Filter and, or Filter Offset values to achieve a slightly blurred effect and reduce the sharpness that causes the swimming.

■

Create a file texture (see Convert a texture or shading network to a File Texture in the Shading guide), then increase the Filter and, or Filter Offset values to achieve a slightly blurred effect and reduce the sharpness that causes the swimming.

■

Increase the Shading Samples value.

Create and load a plug-in multipixel filter Maya software only. To create a plug-in multipixel filter 1 The Plug-in Filter Weight attribute is connected with the plug-in filter node and its value will be used as the filter weight. The filter does not have to be normalized. You can define a plug-in DG node with at least two input attributes and one output attribute with a float type. The input attributes require the short name X and Y. The output attribute has to be connected to the Plug In Filter Weight attribute in the renderQuality node.

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When the plug-in filter type is selected, the plug-in node is evaluated multiple times with different x and y weights, ranging in [-1..1]. The plug-in filter should be defined in the normalized domain [-1..1,-1..1]. The filter width change only affects the mapping of the normalized filter to the pixel coverage. To load a plug-in multipixel filter 1 The following assumes you have already created a multipixel filter plug-in. 2 Copy the filter plug-in .so (Linux), or .mll (Windows), or .lib (Mac OS X) file to: ■

Linux: /maya/bin/plug-ins

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Windows: drive:\Program Files\Autodesk\Maya2009\bin\plug-ins

■

Mac OS X: /Applications/Maya2009/Application Support/plug-ins or to a directory where the Plug-in Manager can read them

3 In Maya, click Window > Settings/Preferences > Plug-in Manager. 4 Load the plug-in you created.

Connect a plug-in multipixel filter To connect a plug-in multipixel filter to the Plug-In Filter Weight 1 In the Script Editor, create a plug-in node by typing: createNode

A node is created for the plug-in. 2 Select the plug-in node by typing in the script editor: select

3 With the plug-in node selected, open the Connection Editor (Windows > General Editors > Connection Editor). 4 Load the plug-in node to the left side of the Connection Editor. 5 Repeat steps 1 and 2 to load the defaultRenderQuality or user-created renderQuality node to the right side of the Connection Editor. 6 Connect the plug-in node’s weight to the defaultRenderQuality Plug In Filter Weight attribute. You can use the multipixel filter plug-in.

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Set raytracing quality Raytracing is a type of rendering where the path of individual light rays are calculated between the camera and the light source. To find out more about how to raytrace to produce shadows, see Raytraced shadows in the Lighting guide. To find out more about how to raytrace to produce reflections, see True reflections in the Shading guide. NOTE You may not need to adjust quality settings for an entire scene. Adjusting settings on a per-object basis is often faster and has less of an impact on rendering speed. To set raytracing quality, adjust the settings in the Raytracing Quality section of the Render Settings window on page 376.

Set motion blur When you render an animation, motion blur gives the effect of movement by blurring objects in the scene. For more information on motion blur, see Focus and blur on page 15.

Maya software rendering specifics Only Maya software supports both 2D and 3D motion blur. To set motion blur, work with the settings in the Motion Blur section of the Render Settings window on page 376. NOTE You may not need to adjust quality settings for an entire scene. Adjusting settings on a per-object basis is often faster and has less of an impact on rendering speed.

General motion blur and Maya Software rendering limitations ■

Motion blur does not work with software particles.

■

When you have a light illuminating a moving object, the object’s shadow does not blur correctly (use mental ray rendering instead).

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■

When you have a moving spot light that illuminates a surface, the spot light’s beam moving across the surface does not blur (use mental ray rendering instead).

■

Motion blur is not rendered in raytraced reflections and refractions.

Maya hardware rendering specifics Supports only 3D motion blur. To set motion blur, work with the settings Motion Blur section of the Render Settings window on page 376.

Related topics ■

mental ray motion blur specifics on page 239

Maya software Set tessellation options Though tessellation is determined on a per-object basis, you can manage how Maya handles the tessellation settings for the scene.

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By default, Maya optimizes the tessellation settings for surfaces by: ■

Storing (caching) geometry information to reduce the amount of memory used.

■

Tessellating identical surfaces only once to save time and disk space.

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Reusing tessellation for the generation of depth maps.

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Calculating the bounding box scale that you define for all displacement-mapped surfaces to make rendering faster.

For more information on tessellation, see Introduction to Tessellation and Approximation on page 39. You can turn these optimization settings on or off in the Memory and Performance Options section of the Render Settings window on page 376. For tesselation settings for mental ray for Maya, see Approximation on page 181.

Set raytracing Though raytracing quality is set by the options in the Raytracing Quality section of the Render Settings window on page 376 (see Set raytracing quality on page 96), you can set scene optimization options in the Memory and Performance Options section of the Render Settings window on page 376. For more information on raytracing, see Raytraced shadows in the Lighting guide.

Set multiple processors You can control the number of processors for interactive rendering. To render with multiple processors, see Network render with Maya software on page 171.

Set IPR options You can control which elements are included in IPR renders in the IPR Options section of the Render Settings window on page 376. For more information IPR renders, see Interactive Photorealistic Rendering (IPR) on page 47.

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Set Paint Effects rendering options See Paint Effects Rendering Options in the Paint Effects, Artisan, and 3D Paint guide.

Set per-material vector rendering options You can control the following attributes on a per-material basis when vector rendering: ■

Fill Object

■

Edge Weight Presets

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Edge Weight

■

Edge Style

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Edge Color

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Hidden Edges

For more information on the above attributes, see Render Settings: Maya Vector tab on page 459. ■

Hidden Edges On Transparent

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Outlines At Intersections

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Edge Priority

For more information on the above attributes, see Vector Renderer Control on page 515. NOTE These attributes are only available on the following material nodes: Anisotropic, Blinn, Lambert, Phong, and Phong E. You can find these attributes in the Vector Renderer Control section in the Attribute Editor for the material node (for example, phong1). To set vector rendering material attributes 1 Select the object with the material for which you want to set vector rendering attributes.

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2 In the Attribute Editor, select the material node, (for example, blinn1). 3 Open the Vector Renderer Control section. 4 Turn on Overwrite Default Values. 5 Adjust the attributes as required.

Work with render layers Work with layers To create an empty layer 1 Do one of the following: ■

Click Create new empty layer icon

■

Select Layers > Create Empty Layer.

in the Render Layer editor.

If this is the first layer you created, the Master layer will also become visible. To create a new layer with selected objects as members 1 Select your objects, and do one of the following: ■

Click the Create new layer and assign selected objects icon the Layer editor.

■

Select Layers > Create Layer from Selected.

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in

To select all objects in a layer 1 Do one of the following: ■

Right-click the layer and select Select Objects in Layer.

■

Select the layer or layers in the Layer Editor and select Layers > Select Objects in Selected Layers.

To add objects to a layer 1 Select the object(s). You may need to do so on the Master layer, where all objects are present. 2 Right-click the layer to which you want to add the objects and select Add Selected Objects. To remove objects from a layer 1 Select the object(s). 2 Do one of the following: ■

Right-click the layer from which you want to remove the objects and select Remove Selected Objects.

■

Select the layer or layers from which you want to remove the objects and select Layers > Remove Selected Objects from Selected Layers.

To remove all objects from (empty) a layer 1 Right-click a layer and select Empty Render Layer from the menu that appears. To get details of layer membership 1 Do one of the following: ■

Right-click a layer and select Membership.

■

Select a layer and select Layers > Membership.

To delete one or more layers 1 Do one of the following: ■

Right-click the layer you want to delete and select Delete Layer.

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■

Select the layer or layers you want to delete and select Layers > Delete Selected Layers.

You can also delete unused layers by selecting Layers > Delete Unused Layers.

Work with layer overrides

To override materials and shaders on a per layer basis: method 1 1 In the Render Layer editor, select a layer. 2 Select Window > Rendering Editors > Hypershade. 3 Select a material from Hypershade, or create a new material, and assign by right-clicking and choosing Assign Material Override from the marking menu.

This creates a material and assignment that will override all shader assignments to objects on the current layer. To override materials and shaders on a per layer basis: method 2 1 You can also override materials and shaders on a per layer basis by right-clicking on a layer in the Render Layer editor and selecting Overrides > Create New Material Override or Assign Existing Material Override from the menu that appears.

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You do not need to have a layer selected to use the context-sensitive menu; right-clicking an unselected layer still allows you to override its materials. To override materials and shaders on a per layer basis: method 3 1 Select a material from Hypershade, or create a new material. To assign this material to the layer, middle-drag the material swatch over the layer.

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To remove a material override 1 Right-click on the layer, and select Overrides >Remove Material Override from the menu that appears. To override layer attributes (render flags) on a per layer basis 1 In the Render Layer editor, select a layer. 2 Open the Attribute editor by right-clicking on a layer and choosing Attributes from the menu that appears. The Member Overrides section of the layer attributes appears. 3 Click a render check box (for example, turn off Motion Blur, turn off Cast Shadows, or assign a shading group to all objects in that layer). When a layer override is applied, the flag icon for that layer appears in color (red)

.

To override render settings, including the renderer, on a per layer basis 1 In the Render Layer editor, select a layer. 2 Open the Render Settings; for example, by clicking the controls (render settings) icon on a layer, or select Window > Rendering Editors > Render Settings. 3 Right-click on a setting name and choose Create Layer Override from the menu that appears.

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The settings you can override on a per-layer basis include: Render Using, Edge Anti-Aliasing, Size Units, and Resolution Units. When a render setting override is applied, the clapboard icon on the layer appears in color (orange)

.

To remove a render flag override 1 Right-click on the layer, and select Overrides >Remove Render Flag Overrides from the menu that appears. To remove a render setting override 1 Right-click on the layer, and select Overrides > Remove Render Setting Overrides from the menu that appears. NOTE You cannot create overrides on the Master layer: any change you make to render settings on the Master layer propagates to all layers that derive from it.

Remove material overrides from objects in any render layer You can remove any material overrides you created on a render layer and revert back to the material shader used in the master layer. To remove a material override from an object in a render layer: method 1 1 In the Render Layer Editor, select the render layer in which you want to remove a material override. 2 In the scene view, right-click the object and select Remove Material Override. A list of material overrides for the selected layer appears in the menu. 3 Select the material override that you want to remove.

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To remove a material override from an object in a render layer: method 2 1 Open the Hypershade (Window > Rendering Editors > Hypershade) to see the material swatch for the material override that you wish to remove. 2 Right-click the material swatch and select Remove Material Override From. The menu lists all objects in the layer that use the material override. 3 Select from the list the object for which you want to remove the material override.

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If a material is currently not used as a material override, the menu displays "There are no objects with override" when you right-click a material swatch and select Remove Material Override From.

TIP The contents of the menu are also useful if you need to query whether a material has been used as an override, or the names of the objects for which it has been assigned as an override.

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Assign different component shading for each render layer You can now assign different component shading groups for each of your render layers. Assume, for example that you have a plane on both layer one and layer two. In layer one, you can now assign half of its faces to a white shader and half of its faces to a black shader. Then, in layer two, you can assign half of its faces to a green shader and half of its faces to a red shader.

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To assign different component shading for each render layer 1 Select a render layer for which you wish to assign component shading. 2 Right-click the object and select Face to convert to Face mode. 3 Select the components for which you wish to assign a shading group. 4 Right-click and select Assign New Material or Assign Existing Material to assign a shading group for the selected components. 5 Select the second render layer for which you want to assign component shading. 6 Right-click the object and select Face to convert to Face mode. In this layer, you can assign component shading groups that are different from the first layer.

Work with attribute overrides All attributes can be overridden on a per-layer basis. Some types of attributes, specifically those applying to Shading Groups and Member Overrides (Render Stats), automatically create layer overrides when you make changes. Other attributes require you to manually specify that you’re making per-layer overrides. To change an object’s material on a per layer basis (auto-overrides) 1 In the Render Layer editor, select a layer. 2 Select the object whose material assignment you want to change. 3 Assign a new material just as you would any new material assignment (for example, right-click and select Assign New Material from the marking menus). Set the attributes of the material. 4 Switch between the selected layer and any other layer and watch the material assignment on the object change in the Scene view. The material assignment on the object applies to the selected layer when Options > Auto Overrides is on. The material assignment applies to the Master layer (and therefore, all objects that are not otherwise overridden) when Options > Auto Overrides is off.

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NOTE Layer overrides are less costly in terms of processing time than per-object overrides. For example, if you select all objects in a layer and override each object’s material assignments by assigning a Lambert shader to them in the scene view, this requires considerably more processing time than creating a material override on the layer that assigns a Lambert shader. To override an attribute on a per layer basis (auto-overrides) 1 In the Render Layer editor, select a layer. 2 Open the Attribute editor. 3 In the Member Overrides section of a shape, click an option (for example, Casts Shadows). The attribute name appears in orange and bold type, indicating that a per-layer override has been made. The change to the attributes of the Member Overrides applies to the selected layer when Options > Auto Overrides is on. The attribute change applies to the Master layer (and therefore, all objects that are not otherwise overridden) if Options > Auto Overrides is off. You can do a manual override if Auto Overrides is off for Member Overrides. See the following procedure. To override an attribute on a per layer basis (manual override) 1 In the Render Layer editor, select a layer. 2 Open the Attribute editor. 3 Click the tab for the particular node whose attribute you want to override (for example, the lambert1 material). 4 Right-click the attribute you want to override (for example, Transparency) and select Create Layer Override from the menu that appears.

The name of the attribute appears in italic and orange text, indicating that it has been overridden on the particular layer.

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If you switch between layers, you see the scene view change, showing a transparent override to the object in one layer, and the default shader assignment in another layer. To remove an attribute override 1 Right-click the attribute whose override you want to remove and select Remove Layer Override from the menu that appears.

Preview layers By default, the Render View will show you a composited view of all layers in your scene with your specified blend modes. You can override this default by changing the value of Render > Render All Layers in the Render View, or Options > Render All Layers in the Render Layer editor. You can choose to only show specified layers or to only show the selected layer in the Render View. As well, you can choose to keep all images that make up the composited Render view, or simply render a single composited image. To preview render layers in the Render View 1 To view all your layers composited with the specified blend mode settings, turn on Render All Layers in the Options menu of the Render Layer editor or the Render menu of the Render View. 2 By default, a composited result of all layers is shown in the Render View. 3 To view all your layers rendered as individual images, change the Render ) from Composite All Layers option (Options > Render All Layers > Layers to Composite and Keep Layers, or just Keep Layers.

NOTE Using Keep Layers significantly increases memory usage in Maya. Consecutive use populates the Render View with more and more images. You must clear out images manually as needed.

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4 To preview the composite of only some layers, turn on Render All Layers, and turn off the Rendering flag on the layers you want to exclude (click on the R icon next to the layer name). 5 To preview a particular layer, select it and make sure the Render All Layers option is turned off. As well, the command-line render supports layers. When you use the -r file flag during a command-line render, each layer will be rendered with the renderer specified in the file. For more information, see Batch and command-line render with layers on page 116.

Layer blend modes To set blending modes for layers 1 Select a layer. 2 Choose a layer blend from the drop-down menu at the top of the Render layer editor. As you activate individual layers, you'll see the layer blend mode change. The following examples show a very simple scene: three spheres colored red, green, and blue, with a small plane in front casting a shadow.

The spheres are in the foreground and are rendered with various blend modes against a white, gray and black background.

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Maya supports the following render layer blend modes: Blend mode

Description

Normal

The foreground texture is applied like a decal to the background. The shape of the decal is determined by the foreground alpha.

Lighten

Uses whichever pixel in the rendered layer is lighter as the resulting color.

Example

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Blend mode

Description

Darken

Uses whichever pixel in the rendered layer is darker as the resulting color.

Multiply

Multiplies the composited render's color by the rendered layer color. The resulting color is always a darker color. Multiplying any color with black (value of 0) produces black. Multiplying any color with white (value of 1) leaves the color unchanged.

Screen

Multiplies the inverse of the rendered layer and the composited layers colors. The resulting color is always a lighter color. Screening with black leaves the color unchanged. Screening with white produces white.

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Example

Blend mode

Description

Overlay

Multiplies the colors, depending on the composited color. Patterns or colors overlay the existing pixels while preserving the highlights and shadows of the base color. The base color is mixed with the rendered layer color to represent the lightness or darkness of the original color.

Example

NOTE If you use any other render layer blend modes, the preview results may not be what you expect; however, the results may be helpful for determining layer priority and other layering factors.

Render layers to PSD format You can render all layers to Adobe Photoshop (PSD) format. A PSD file is created during a render with each layer in your scene as a separate layer in this PSD file and with all blending modes specified as they were specified in the Maya file. When you open this file in Adobe Photoshop, each render layer in your Maya scene will have a corresponding layer and blend mode in the PSD. The PSD file is rendered directly to the image directory of your project and not in a subdirectory. To render to PSD layer file format 1 In the Common tab of the Render Settings, select PSD layered (psd) from the Image Format list.

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You can open the PSD file created in Adobe Photoshop.

Batch and command-line render with layers Batch and command-line rendering interacts with render layers. Read this section to learn how they work together.

How frames are rendered with render layers on the command-line When command-line rendering in previous versions of Maya, each render layer of a frame was rendered before moving on to the next frame. In order to properly support the use of different renderers with different layers in Maya 8, rendering from the command line (render) renders all frames of

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a particular layer before moving on to the next layer, as seen in the following diagram.

Previous render behavior is shown by the dashed arrows; current render behavior is show with the green arrows. Layers are rendered in the order they appear in the layer manager. This may have an impact on dispatchers and other render managers because scripts that are triggered by completion of a particular frame won’t be triggered until the last layer is being rendered. NOTE The frame/layer order of processing in batch and command line is required for maximum efficiency. Switching layers has an impact on render processing due to the need to update all the attribute overrides. To render all layers in the command-line renderer 1 At a Command Prompt, Terminal window, or shell, type the following: render -r file

The batch renderer will use the specified renderers in the file per-layer to render the scene. Additionally, the -rl flag specifies which layer to render. For example, Render -r file -rl layer1 renders layer1 with the renderer specified in layer1; Render -r sw -rl layer1 renders layer1 with the software renderer, no matter what renderer is specified in the file.

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NOTE The default renderer is the Maya software renderer. When no renderer option is specified when using the render command, Maya uses a renderer called default. When Maya is installed, the software renderer specification is copied to default. If you want to change the default renderer (for example, to use the file renderer, which renders the scene based on the renderer specified in each render layer), copy: /bin/rendererDesc/fileRenderer.xml

to /bin/rendererDesc/defaultRenderer.xml

Duplicate an existing render layer You can duplicate any layer in your Maya scene. You can use this feature to create two layers that are similar with only minor differences. For example, use this feature if you want to have two identical layers, but with raytracing turned on for one layer and turned off for the other. With this feature, you do not need to create the two layers independently you only need to create one layer and duplicate it. This eliminates the need to reassign objects, materials and attributes in order to create the second layer. There are two options available with this feature: ■

You can choose to copy both the objects and render layer properties (e.g. material overrides, render stats) to the new layer; or

■

You can choose to copy only the objects to the new layer and create new overrides for the duplicated layer.

To duplicate an existing render layer 1 From the Render Layer Editor, select the layer that you wish to copy. 2 Select Layers > Copy Layer > 3 Select one of the two Copy Layer mode. To create an exact duplication of the selected layer, including objects and render layer properties, select

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With Membership and Overrides. To carry over only objects, select With Membership.

Naming render layers The filename for the rendered image of each layer can be customized using the workflow as follows. To name your render layers 1 From the Render Layer Editor, select the layer that you wish to name. 2 Open the Render Settings window (Window > Rendering Editors > Render Settings). 3 Click on the Common tab. Under the File Output section, right-click the File Name Prefix attribute and select Create Layer Override. 4 Enter the desired filename for the selected render layer. After the image is rendered, the image output for the selected layer will be saved under the filename as entered.

Recycling rendered images to save time If you have a Maya scene with more than one render layer, you can recycle the rendered image for the layers that are done. This saves rendering time by eliminating the need to re-render layers that you can reuse. You can use this feature in one of the following scenarios: 1 If, for example, you have five layers in your scene, and 4 of them are fine but 1 layer still needs work. In this case, you can keep the render output for the four layers that are fine, and only re-render the one layer that is in progress. This greatly reduces rendering time as compared to re-rendering all five layers. 2 All of your layers are fine, but you need to re-order them in the composition. 3 All of your layers are fine, but you need to change the blend operator for one or more layers (e.g. changed the mode of your shadow pass from Normal to Darken).

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In the second and third cases, you can keep the render output for all layers. A render that only reorders layers and composites them is much faster in comparison to re-rendering every layer in your scene again. To recycle render output for one or more layers 1 Render a layer. Its recycle icon changes from grey to red. 2 Click the layer you want to keep. Click the recycle icon to toggle it from red to green. The last rendered output image for this layer will be reused and this layer will not be re-rendered. Repeat for all layers whose render output you want to recycle. NOTE ■

The recycle icon is grey until the layer has been rendered at least once. A green recycle icon saves the rendered image and allows for faster re-compositing while a red recycle icon will force re-rendering prior to compositing.

■

Render output is only held in memory for your current session of Maya. Any render output is lost after you quit the current session of Maya.

Control visibility/reflection per layer You may want to have a render layer that contains only reflections and refractions of an object, but have the object not be visible on that layer. The primary visibility attribute in the Render Stats allows an object to reflect and refract, but the object itself does not render. To do so, both the visible objects and the hidden objects (the objects for which you wish to show reflection and refraction) must belong to the same layer.

To hide an object but show its reflections and refractions 1 Select Window > Rendering Editors > Render Layer Editor. 2 In the Render Layer Editor on page 367, select the layer on which you want to hide the object(s).

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3 Select the object. The Attribute Editor with the selected object’s attributes appears. 4 Uncheck Primary Visibility in the Render Stats section of the object’s shape node. The Primary Visibility attribute turns orange, indicating that visibility is overridden on this layer.

Related topics ■

Render Layer Editor on page 367

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Render Stats on page 511

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Work with layer overrides on page 102

Work with render layers | 121

Merging display layers or render layers when importing files When you import a file into Maya, you can merge the display layers or render layers from the imported file into your current scene. You can merge layers of the same name or of the same index number. For example, if you choose to merge display layers by name, then all objects on the layer named MyLayer of the imported file will be merged with objects on the layer named MyLayer of your current scene. The merged layer will retain its name MyLayer. To merge display/render layers by layer name 1 Ensure that the layers that you wish to merge share the same layer name. Click on the Display/Render radio button in the Render Layer Editor to view the desired layers. To change the layer name, double-click the layer for the Edit Layer dialog box to appear. 2 Select Window > Settings/Preferences > Preferences, click the Files/Projects category, and in the Display Layer section (or Render Layer section), select By Name. 3 Import the file by selecting File > Import. To merge display/render layers by layer number 1 Ensure that the layers that you wish to merge share the same layer index number. Click on the Display/Render radio button in the Render Layer Editor to view the desired layers. To edit the layer index number, right-click the desired layer and select Attributes from the right-mouse menu to display the display/render layer’s Attribute Editor. Enter the layer number in the Number attribute. 2 Select Window > Settings/Preferences > Preferences, click the Files/Projects category, and in the Display Layer section (or Render Layer section), select By number. 3 Import the file by selecting File > Import.

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Related topics ■

Display Layer of the Basics guide.

■

Render Layer of the Basics guide

Visualize a scene Visualize interactively with IPR Maya software only. When you drag a marquee (render region) around the entire scene or part of the scene, the IPR image begins to update. If you change lights, shadows, materials, textures, and post processes (special effects) such as glow and fog, you can see the results of your changes interactively. For detailed information on IPR rendering, see Interactive Photorealistic Rendering (IPR) on page 47. NOTE The amount of memory used during an IPR session may be considerable. The upper-right corner of Render View displays how much memory is being used for the current IPR tuning region. To visualize scene adjustments interactively 1 Do one of the following: ■

Click the scene view you want to render, then click the IPR Render button (from the Status Line or from within Render View if it is open). The scene appears in Render View, and an IPR image is created.

■

To load an existing IPR file, select File > Open IPR File..., then select the file.

2 Marquee select a region within the IPR rendered image in Render View. NOTE You must select a region to adjust before you start to modify rendering attributes. The region you select determines the amount of memory required by IPR to re-render the adjusted region.

Visualize a scene | 123

3 Adjust the scene, for example, add lights or modify materials and texture attributes. The selected region of the IPR image updates as you adjust the scene. ■

To render another view instead, select IPR > IPR Render in Render View and select a view from the drop-down list.

■

If you change the view (such as tumble or zoom, or add new elements to the scene) and want to update the result, click the Redo Previous IPR Render icon in Render View or from the Render menu in Maya’s main menu bar.

■

If you only want to change certain elements such as lighting or textures and do not change the view, simply drag a marquee around the object or part of the object you want to update. The results in Render View are immediate.

TIP After you marquee select a region, you can drag materials and textures onto objects within the region, just as you can make connections by dragging swatches from Hypershade onto surfaces in the views.

Pause, cancel or save an IPR render To pause an IPR render 1 Press the pause button. To cancel an IPR render 1 Press Esc. The IPR render stops. You cannot adjust a cancelled IPR Render; you must perform a complete IPR Render to adjust a region.

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To save an IPR file 1 Select File > Save IPR File.... The Save IPR File window displays. Type the name of the file and click Save. NOTE Because an IPR file saves the deep raster information in addition to the visible color information, an IPR file can be very large. Ensure you have sufficient disk space.

Batch render IPR files You can batch render IPR files from the command line. For more information about batch rendering or command line rendering, see Batch renders from within Maya (UI) on page 52 and Render from a command line on page 53. To batch render IPR files 1 In a shell or command line, type: Render -r sw -ipr true

See Render from the command line in the Rendering Utilities guide for information and flags about batch rendering from the command line. NOTE ■

You cannot batch render IPR files from within Maya.

■

Batch rendering to produce IPR files is not multi-threaded.

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See shading and lights in a scene view

Hardware texturing, a Maya feature that you can easily turn on or off, lets you to see approximations textures, lights and objects in your scene in a scene view. What you see depends directly on the settings you make in the Render Settings window on page 376 and per-object settings you change. What you see is not necessarily what appears in the final render, but it gives you a good idea. NOTE If you are using a file texture that uses MirrorUV and the resolution of the hardware rendered texture in the scene view appears degraded, use the following environment variable: MAYA_HW_FILE_TEXTURE_RESOLUTION_OVERRIDE

TIP To see the resolution boundaries in the scene view, turn on the Resolution Gate. For more information, see Turn scene view guidelines on or off on page 24. To see textures, lights, and objects in a view port 1 In the scene view, select Shading > Smooth Shade All. 2 Select Shading > Hardware Texturing (or press the hotkey 6). 3 Do any of the following (optional): ■

To use all lights in the scene, select Lighting > Use All Lights (or press the hotkey 7).

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■

To see a more accurate preview result (which may take a little longer), adjust the Hardware Texturing attributes in the object’s material’s Attribute Editor. NOTE When you play an animation with just Hardware Texturing turned on, each of the necessary file textures are read in one at a time and the animation speed is choppy. Use Interactive Sequence Caching Options to load file textures into memory only once for faster interactive animation (but this uses a lot of memory).

Test render a low-res still or frame The time Maya takes to software render a scene is directly proportional to the resolution: the larger the resolution, the more time it takes. If you want to get a feel for the final rendered look quickly, you can render of a still image or single frame of an animation. Typically, a resolution half to a quarter of the size lets you get a good feel for the software rendered look. NOTE To ensure the best quality display of your rendered image, select the 1:1 (the real size) option in Render View before you render. To test render a still image 1 From Render View (Window > Rendering Editors > Render View), click Options > Test Resolution, then select a resolution. 2 Select the camera view you want to render from the Render > Render submenu. Maya renders the scene and displays the image as it renders in Render View. ■

To cancel the render, press Esc.

■

To re-render the frame, select Render > Redo Previous Render.

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Test render a low-res animation If you want to get a feel for the final rendered look quickly, you can render of an entire animation (or a few selected frames) at a lower resolution. Typically, a resolution half to a quarter of the size lets you get a good feel for the software rendered look. (As you get closer to achieving the final look during an animation, test render a few specific frames at the final resolution too.) To test render an animation with command line rendering 1 From a shell or command line, type: Render -r

using the following options: -s

The first frame of the animation to render.

-e

The last frame of the animation to render.

-b

The increment between frames to render.

-x

The horizontal resolution of the rendered images.

-y

The vertical resolution of the rendered images.

For example, if an animation begins at frame 1 and ends at frame 100, and the final image resolution is 640 x 480, and you want to test render with Maya software the animation by rendering every ten frames, type: Render -r sw -s 1 -e 100 -b 10

If you want to test render the animation by rendering with mental ray for Maya every frame at half the final resolution, type: Render -r mr -s 1 -e 100 -b 1 -x 320 -y 240

For a complete list of Render options, in a shell or command line, type: Render -r -help

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Render selected objects TIP Render at 1:1 resolution for fastest feedback. You can isolate specific objects to render. Note that when using IPR rendering, you must perform another IPR render before you can see the effect of this change. To render selected surfaces 1 Select the objects you want to render. 2 In the Render View window, select Render>Render Selected Objects Only. 3 Render the scene.

TIP You can display a wireframe snapshot of your scene to use as a guide to select a region of your scene to render. In Render View, select Render > Snapshot > and select the camera (view) you want to capture.

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Render a region of your scene

Render View lets you render a specific portion of your scene at any resolution so that you can get a feel for the changes you make as you shade, light, and texture objects. Unlike rendering at a lower resolution, a process which reduces the size of the entire image, rendering a region can help you make changes more efficiently and quickly to the specific regions of interest at full resolution. TIP If you turn on Auto Render Region (Options > Auto Render Region), the changes you make appear as you draw the marquee anywhere in Render View. Only the marqueed area of the surface re-renders showing the results of the adjustment. To render a region of your scene 1 Marquee select the area that you want to render in Render View. 2 If there is no representation of your scene in Render View for you to marquee select Render > Snapshot > and select the camera (view) you want to capture. 3 Click the Render region button or select Render > Render Region.

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Perform final renders from within Maya Render a single frame When you render or re-render a single frame from Maya’s main window, the render appears in Render View. For more information about using Render View, see Render View rendering on page 52. The image is automatically saved to the images directory of the current project. TIP Render at 1:1 resolution for fastest feedback. NOTE Navigation in the Render View panel is like most other Maya view panels. You can zoom and track the view using the same keyboard shortcuts. To render a frame from within Maya 1 From the main Maya window, click the Render Current Frame button, or select Render > Render Current Frame. Maya renders the scene from the current scene and displays the image as it renders in Render View. To cancel an in-progress render, press Esc. To re-render a frame from within Maya 1 From the main Maya window, select Render > Redo Previous Render. Maya renders the scene from the previous camera and displays the image as it renders in the Render View window. To cancel the render 1 Press Esc.

Batch render a still or animation NOTE By default, Maya renders the current frame of your scene. To render an animation, you must specify the start and end frames of the animation you want to render in the Render Settings window on page 376.

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On Linux, you can select a remote host on which to render the current scene. To batch render from within Maya 1 Do any of the following: ■

ClickRender > Batch Renderto batch render.

■

To cancel the render, click Render > Cancel Batch Render

■

To show the image being rendered, click Render > Show Batch Render. NOTE ■

To set batch render options, select Render > Batch Render > to open the Batch Render window. For a description of the batch render options, see Render > Batch Render >

■

.

When using the Maya Batch Renderer on a remote machine the User Account information (i.e. username) must be consistent between the machines to ensure that User Authentication will function correctly.

Render with several processors You can render a scene on a computer that has more than one processor and make use of some or all of its available processors. NOTE We recommend that you use a single processor when batch rendering a scene that contains a spotlight, material transparency, and raytrace shadows. To render on a computer with several processors from within Maya 1 From the Maya window, select Render > Batch Render >

.

The Batch Render Frame window displays. 2 To use all available processors on your computer for rendering, turn on Use all available processors. 3 To use only some of the available processors on your computer for rendering, turn off Use all available processors and set Number of Processors to Use to the number of processors you want to use.

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4 Click Batch Render. Maya renders the animation. To render on a computer with several processors from a shell or command line (Maya software rendering only) 1 Type: Render -r sw -n

(If you do not use the -n option, only one processor is used for rendering.) Examples (for Maya software rendering only): ■

To use one processor for rendering, type: Render

■

To use two processors for rendering, type: Render -n 2

■

To use all processors on your computer for rendering, type: Render -n 0

Perform command line rendering Command line rendering Your scene file determines whether you render a single frame or an animation. You can render from a shell or a command line. Before rendering, you may want to close all applications, including Maya, to maximize the amount of memory available for rendering. When you render from a command line, you can set flags that override some of the Render Settings, saving time during test renders. For more information, see Render from the command line in the Rendering Utilities guide. To get quick renderer-specific information 1 Type: Render -r rendername -help

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where rendername is the name of the renderer. Use the following options: ■

mr = mental ray

■

sw = software renderer

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hw = hardware renderer

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vr = vector renderer

■

file = the file within which the renderer is specified NOTE If you get help on a file (-r file -help), only the flags common to all renderers, not a specific renderer, are shown. If you want renderer-specific information, you must specify the renderer.

All flags have a short description. Each flag corresponds to the appropriate section of the Render Settings window. See the Render Settings documentation for more detailed information on each option. To obtain a complete list of command line Render options, from a shell or command line 1 Type: Render -help

To render a scene with a specific renderer from a shell or command line 1 Type: Render -r scene

TIP You may need to provide the -proj flag when issuing the render command to specify where the scene file is located. For example, type: Render scene -proj

To render a scene with the renderer specified in the file from a shell or command line 1 Whichever renderer is specified in the file is used to render the scene. Type:

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Render -r file

To batch render using user-defined region rendering 1 Use the -reg flag. For example: render -r mr -reg 0 100 0 100 scene.ma

where -reg 0 100 0 100 indicates the region to be rendered in pixels (left, right, bottom, top). The above command renders the lower left 100 x100 pixel region of the scene.

Render multiple scenes Render multiple scenes You can either write a batch script that starts renders in succession or use a third-party management solution.

Work with the Compositing Interoperability plug-in Work with Autodesk Toxik 2007 The Compositing Interoperability plug-in allows you to export information from your Maya scene to Autodesk Toxik 2007. The Compositing Interoperability plug-in includes Maya menu extensions for Autodesk Toxik 2007. When you load the plug-in, a Toxik-specific menu item appears in the Maya Render menu. Using this plug-in, you can generate a preliminary Toxik composition from within Maya based on the render layers in your scene. The compositing graph includes the associated image sequence filenames, Maya blend modes and layer-specific render settings.You can export all the layers in your scene, or selected layers. This allows you the flexibility to export all the layers in your scene, and then make changes and export only the changed layers if necessary. You can work in one of two output modes: Export Toxik IMSQ File, or Update Toxik. If you are not running Toxik on the same machine that Maya is running

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on, use the Export Toxik IMSQ File mode, which allows you to save the Toxik script and run it on the machine where Toxik resides. If you are running Toxik and Maya on the same machine, you can work in the Update Toxik mode, which automatically updates the Toxik database and makes the Toxik composition available immediately. To work in Update Toxik mode, Python 2.4 is required. For more information on Python, see http://www.python.org. NOTE ■

You must use image file formats that are supported by Toxik. See the Toxik user documentation for more information on supported file formats.

■

When exporting to Toxik, you should render the layers in your scene to the same Maya project directory because the Compositing Interoperability plug-in expects each layer to have the same base path.

Limitations Update Toxik mode limitation The first time you export a scene from Maya, one Toxik image sequence composition is created for each render layer. In addition, a master Toxik composition is created, which references the Toxik image sequence compositions. When you export the scene from Maya again, the Toxik image sequence compositions are updated but the master Toxik composition is not. As a result, each image sequence composition contains a new published result, which is not reflected in the master Toxik composition. You can use the following procedure to recreate the master Toxik composition. This is useful in some cases where: ■

The Maya scene has changed significantly (due to blend mode changes, new layers, and layer shuffling, for example).

■

You need to start a new master Toxik composition.

To update an existing master Toxik composition 1 Close the existing master Toxik composition in Toxik (if it is open). 2 In Maya, select one of the following: ■

Render > Export All Layers to Toxik 2007 >

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.

■

Render > Export Selected Layers to Toxik 2007 >

.

The corresponding options dialog box appears. 3 Enter one of the following in the Python Script Arguments field: ■

-r

■

--recreate

4 Click Export. Your existing master Toxik composition is updated, as well as each Toxik image sequence composition. 5 Remove the -r or --recreate argument from the Python Script Arguments field before exporting again. To update Toxik 1 Load the compositingInterop plug-in from the Maya Plug-in Manager (see, Load or unload Maya plug-ins). 2 If you are exporting selected layers in your scene, select them from the Render Layer Editor (see Render Layer Editor on page 367). 3 In Maya, select one of the following: ■

Render > Export All Layers to Toxik 2007 >

.

■

Render > Export Selected Layers to Toxik 2007 >

.

The corresponding options dialog box appears. 4 Adjust the Toxik User Settings and Toxik Scene Settings options as necessary. For information on these options see Render > Export All Layers to Toxik 2007 on page 334. 5 In the Output Settings > Output Mode, select Update Toxik. 6 In the Python Location field, enter the path to the executable file for Python (python.exe), or click the Browse button to select it. 7 Click Export. Your Toxik database is automatically updated with the exported information, and you can view the corresponding graph within Toxik.

Work with the Compositing Interoperability plug-in | 137

IMPORTANT ■

To work in Update Toxik mode, Python 2.4 is required. For more information on Python, see http://www.python.org.

■

The Update Toxik mode is only available on platforms supported by Toxik. See the Toxik user documentation for more information on supported platforms.

To save a Toxik script 1 Load the compositingInterop plug-in from the Maya Plug-in Manager (see, Load or unload Maya plug-ins). 2 If you are exporting selected layers in your scene, select them from the Render Layer Editor (see Render Layer Editor on page 367). 3 In Maya, select one of the following: ■

Render > Export All Layers to Toxik 2007 >

.

■

Render > Export Selected Layers to Toxik 2007 >

.

The corresponding options dialog box appears. 4 Adjust the Toxik User Settings, Toxik Scene Settings and Output Settings options as necessary. For information on these options see Render > Export All Layers to Toxik 2007 on page 334. 5 In the Output Settings > Output Mode, select Export Toxik IMSQ File. 6 In the File Name field, type a name for the output. By default the output file is stored in your project directory; however, you can click the Browse button to specify an alternate location for the file. 7 Click Export. The output file is created and placed in the specified directory (by default, this is your Maya - Project - Default directory). 8 Run the saved script on the machine where Toxik is installed: On Windows, in the Autodesk Toxik 2007 DOS command shell, enter the following: c:\python24\python "C:\Program Files\Autodesk\Maya2009\bin\ toxik-maya-import.py" path\toxikComp.imsq -toxikPath "C:\Program Files\Autodesk\Autodesk Toxik 2007" -tempPath %TEMP%

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On Linux, in Tcsh, enter the following: source /opt/Autodesk/Autodesk_Toxik-2007/bin/toxik-env.csh

then enter: python_t /usr/autodesk/Maya2009/bin/toxik-maya-import.py path/toxikComp.imsq -toxikPath "/opt/Autodesk/ Autodesk Toxik 2007" -tempPath /var/tmp

Work with Autodesk Toxik 2008 The Toxik 2008 Export feature allows you to export information from your Maya scene to Autodesk Toxik. Unlike Toxik 2007, which requires that you install the compositingInterop plug-in, the Toxik 2008 Export feature is automatically loaded into Maya.Using Toxik 2008, you can generate a Toxik project file from within Maya based on the render layers in your scene. The compositing graph includes the associated image sequence filenames, Maya blend modes and layer-specific render settings. ■

You must use image file formats that are supported by Toxik. For example, you must avoid using the name.ext.# image file format, as this file format is not compatible with Toxik. Instead, rendered image sequences should be named with the file extension listed last, for example, name.#.ext. This is necessary for Toxik 2008 to recognize the sequence. See the Toxik user documentation for more information on supported file formats.

■

When exporting to Toxik, you should render the layers in your scene to the same Maya project directory because the Toxik 2008 Export plug-in expects each layer to have the same base path. To export a scene to Toxik 2008 1 Ensure that you have set a project for your scene file. Within the project, there must be a scenes folder. By doing so, the exported Toxik project file will be saved to the scenes folder by default. You may also enter an Images folder to which your sequences will be stored. 2 Batch render your scene in Maya and ensure that the rendered image sequences are named with the file extension listed last, for example, name.#.ext. 3 Select Render> Render toToxik 2008 > . The Export All Renderable Layers to Toxik Options dialog box appears.

Work with the Compositing Interoperability plug-in | 139

4 You may leave all fields blank with the exception of Toxik Install Directory. By default, Maya will give the Toxik project file the same name as your scene file and save it to the same folder as your scene file. For example, if your scene file is myscene.ma, the corresponding Toxik project file will be myscene.ma.txproject. 5 Select Export. Expect a pause as the scene file is exported to Toxik. 6 In Toxik, click on the Existing tab and locate your myscene.ma.txproject file. Select Composition > Open to open the file. NOTE Do not simply select Render > Export to Toxik 2008 on page 336 without selecting the option box.

Related topics ■

Render > Export All Layers to Toxik 2007 on page 334

■

Render > Export Selected Layers to Toxik 2007 on page 335

Troubleshooting Rendering Troubleshoot image plane displays black swatch An Image plane not connected to a camera displays black swatch. Once connected to a camera, the swatch will function properly.

Troubleshoot displacement is not displayed The Display render tessellation on page 517 option does not display displacement mapping. In the main Maya window, select Shading > Displacement to Polygon to preview the effect of your tessellation and displacement together, then discard the generated polygon object when you are finished previewing.

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Troubleshoot software-rendered is too bright By default, Point and Spot lights have no decay. Open the light’s Attribute Editor and change the Decay Rate, or use Maya’s Decay Regions (for spot lights only) to control the decay.

Troubleshoot Multi-UVs for NURBS don’t software render Multi-UVs defined for NURBS are currently not respected when software rendering.

Troubleshoot NURBS surface does not appear when rendering If a NURBS surface is disconnected from its shading group, it will continue to be drawn in shaded mode but will not appear when rendering. This is different from polygon objects which will not appear in shaded mode in this situation. Make sure that your NURBS surface is connected to its shading group, and then try rendering again.

Troubleshoot rendered image doesn’t match interactive window display In rare cases, a rendered image may not match what is displayed in the interactive window. This may be caused by different Dependency Graph solutions if nodes are evaluated in a different order. The most common occurrences are: renders that are divided among multiple machines produce inconsistent results; an arbitrary frame within an animation range is rendered alone; or rendering with motion blur produces different results than rendering without motion blur. Scene elements which may produce undesirable render matching include: ■

Any dependency graph cycle.

Troubleshooting Rendering | 141

■

Animated nodeState on any node.

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Animated transform limits.

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The multi-chain IK solver.

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Expressions that modify values based on a previous value. For example: tx = tx + 1.

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Expressions that conditionally set values. For example: if (ty > 5) tx = ty.

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Expressions that execute commands (or create or delete Maya nodes). For example: sphere.

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Particle/softbody solutions (because of timestep changes).

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Geometry Constraint nodes (because they go to the point on the target geometry that is closest to the current point).

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Any constraint where the sum of the target weights is zero.

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Aim, tangent, or normal constraint or lookAt nodes with the worldUpType attribute set to None.

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Aim, tangent, or normal constraint or lookAt nodes with the upVector co-linear with the aimVector.

■

IK with an animated solverEnable value.

Workaround The renderer can invoke a MEL procedure just before you render a frame. (You specify this script in the Render Settings > Render Options > PreRender Mel text field.) You can use this procedure to force evaluation at the intervening skipped frames. To use a MEL script 1 Put the MEL script (named preFrameProc.mel) in your Maya scripts directory. 2 Under Render Settings > Render Options, type preFrameProc in the PreRender Mel field. If motion blur is on, you may need to bake the animation.

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Troubleshoot projection texture swims over an animation Projection texture with useLocal, can swim over an animation. Turn on Use Local on all upstream textures to work around this.

Troubleshoot transparent blobby surface rendering anti-aliasing problem With transparent blobby surface rendering, anti-aliasing may be poor, even at the highest-quality settings. Such cases include intersecting transparent blobby surfaces and transparent blobby surfaces behind transparent geometry. To fix this, increase the number of Particles in the section Number of Samples in theRender Settings.

Troubleshoot memory exceptions On some 32-bit Windows machines virtual memory is restricted to 1.6 Gbs (or thereabouts). It doesn't matter if you have hundreds of giga-bytes of physical memory or swap, no process can grow larger than this size. Maya may encounter a memory exception and report that there is still lots of memory available.

Troubleshoot highlight artifacts close to object edge If you have tessellated an object with the Use Smooth Edge on page 330attribute and you get artifacts in highlights along curved parts of the surface close to an edge, don’t use this attribute. This caused the curvature in the surface to be slightly different closer to the edge, which doesn’t work for strong highlights.

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Troubleshoot background surfaces show through Especially in large scenes that have objects close together, background surfaces may appear to show through nearby surfaces. This is a result of how the camera’s clipping planes determine depth position of geometry. To fix this problem, see Clipping planes on page 21.

Troubleshoot objects vibrate when an animation is rendered as fields For Maya software rendering only. The settings you use for rendering images as fields may depend on the hardware or software settings you are using with the images, and how they interlace fields together (for example, the interlace utility, compositing software, or frame buffer device). Before you render an animation as fields, perform a test render and use the test rendered images through your entire post-production process (see Batch render a still or animation on page 131 and Test render a low-res animation on page 128). Even though Maya automatically sets these options depending on whether the Resolution is NTSC or PAL, if you encounter problems in the animation where objects vibrate up and down, change the Zeroth Scanline setting and test render the animation again. If this does not solve the problem, or if objects in the animation vibrate left to right, try different combinations of Field Dominance and Zeroth Scanline, and test render the animation until the problem is solved.

Troubleshoot 2D Motion Blur problems For Maya software rendering only.

If dark halos display around the objects Try the following: ■

Make sure the background color is black

■

Make sure Smooth > Color is turned on if there is fog in the scene.

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Moving transparent objects with a background The background is also blurred in this case even though it should not be. The solution is to blur the transparent object separately and composite with the rest of the scene. This workaround can be difficult for complex scenes with lots of transparency, or for transparent particles.

Detailed background behind moving objects Some details may be lost because assumptions must be made about the background area occluded by the moving objects. The solution is to blur the moving objects without the background and then composite the results.

Rotating objects May not look exactly right, because assumptions about what the back sides of these objects should look like must be made. Try using 3D motion blur.

Objects entering from outside the image or leaving the image The edges of frames may not get the correct detail, because assumptions must be made about the object color that is just outside a frame. The solution is to render a slightly larger image which covers the original image and then crop it to the desired size.

Rendered results from 3D and 2D are quite different Try not to mix the rendered images from two different kinds of blurring operations.

Tuning 2D motion blur with IPR When tuning 2D motion blur with IPR, automatic updates are not always done correctly. Tune an attribute of a material or light to force a correct update, or marquee the tuning region to force an update.

2D motion blur artifacts 2D motion blur can cause artifacts when rendering in scenes with fog, or solid objects in front of transparent ones, or if the background color is not black.

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There are three possible workarounds: ■

Take out transparent objects, fog, glow, and background color from the scene. Render the 2D blur and composite those elements back into the scene.

■

Set the Smooth Value to 0. In the command line, this is -m 0. This solution is to skip the smooth-mask operation. The image may look more aliased as a result.

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Turn on Smooth > Color. In the command line, this is -r 1. This solution uses a different smoothing algorithm. The image may look more blurry as a result.

Troubleshooting Surfaces (Maya software) To fix faceted surface edges or profile 1 Do any of the following: ■

Run Set NURBS Tesselation.

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Make sure Automatic is set in the Render > Set NURBS Tessellation window.

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Turn on Smooth Edge for the surface (or turn on Smooth Edge and increase Smooth Edge Ratio).

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Increase Curvature Tolerance for the surface and U Division Factor/ V Division Factor for the surface (to the lowest values that produce acceptable results).

To fix aliased surface edges or profile (for Maya software and mental ray for Maya) 1 If you do not plan to composite the rendered image, turn on Premultiply in the Render options section of the Render Settings window on page 376.

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To fix flickering thin surfaces (for Maya software only) 1 Do the following: ■

In the Render Settings window on page 376, turn on Use Multi Pixel Filter.

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Turn on Geometry Anti-aliasing Override for the surface, and increase the Anti-aliasing Level (try 3, 4, or 5).

To fix flickering textures or popping displacements 1 For solid textures, make sure Use Min Screen is off for the surface and Mode U and Mode V are not set to Best Guess Based on Screen Size. For image file textures or textures with noise, Increase Filter Offset (to the lowest value that produces acceptable results). For image file textures, set Filter Type to Quadratic for the texture.

To fix outlines around 2D motion blurred surfaces (for Maya software only) 1 Do either of the following: ■

Remove transparent objects, fog, and, or glow, and set the background color to black. Render the scene, then composite the elements you removed with the rendered image.

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In the Render Settings window on page 376, set Smooth Value to 0 and turn on Alpha/Color.

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To fix grainy or flickering highlights (for Maya software only) 1 Do either of the following: ■

Make sure “Use Min Screen” is off for the surface and Mode U and Mode V are not set to “Best Guess Based on Screen Size”.

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Use a Blinn material instead of a Phong or PhongE material.

To fix jagged edges or jagged or sharp textures on motion blurred surfaces (for Maya software only) 1 In the Anti-aliasing Quality section of the Render Settings window on page 376, set Presets to 3D Motion Blur Production.

To fix jagged surface edges, textures, or shadows in raytraced reflections or refractions (for Maya software only) 1 In Render Settings window on page 376, set the Anti-aliasing Quality to Contrast Sensitive Production (Highest) quality, then turn on Shading Samples Override for the reflecting/refracting surface, and increase Shading Samples (to the lowest value that produces acceptable results).

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Troubleshoot edits in the Texture Editor don’t update in IPR Edits you make in the texture editor don’t update in IPR. You must re-render the scene.

Troubleshoot looping renders Cycles in a render node network cause the renderer to loop forever. A cycle is when two or more nodes mutually depend on each other for their information. Do not construct a render node network with cycles. If you create a cycling render node network accidentally, break one or more of the cycles using the Connection Editor before you render.

Troubleshoot render tiles There are two cases where the tiling the renderer chooses may not be optimal. Case 1 Over an animation texture, chattering can occur because the tiling configuration changes. This does not happen very frequently but if you have a noise-based texture on an object that is not moving and you have another object (highly tessellated) that is moving you can sometimes see texture crawl because of tiling changes. The way to check if forcing tile sizes will alleviate the problem is to observe if over the animation the texture shift is occurring in a rectangular region (aligned to tile boundaries). Case 2 Sometimes the memory estimation is wrong and your rendering job can't finish. If you see something like: Error: Free memory is low. Memory exception thrown

You can try to force the tile sizes to be smaller so the rendering job fits into memory. When using command line rendering, use the -reg flag. For more information on this flag, see Common flags for the command line renderer in the Rendering Utilities guide.

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Troubleshoot assigning objects to Render Layers through the Relationship editor Assigning objects to Render Layers via the Relationship editor is not recommended since you may inadvertently assign an object without it's transform. Instead, use the Render Layer editor to assign objects to layers.

Troubleshoot render layer color indicators do not appear correctly (Linux only) If you have a modified MayaScheme file, you may not see the correct layer indicator colors for selected layers in the Layer editors (light blue and darker blue). As well, you may not see the correct color indicator for the override of layer attributes (orange and bolded). Workaround Add the following lines to your custom MayaScheme file: *layerAdjustmentTextForeground: #e56929 *blueSelectBackgroundColor1: #3884c4

*blueSelectBackgroundColor2: #81a7c1

Troubleshoot Interactive Photorealistic Rendering (IPR) IPR image plane display options IPR doesn’t respect image plane display options. When updating, IPR displays the image plane in the background though the image plane is set to none. Workaround Delete the image plane.

Manual feedback from IPR Manual updates are needed to get feedback from IPR when making changes to: ■

image planes

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shadow maps due to light location changing, depth map resolution changing, or the auto focus changing

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tessellation Workaround Redo the IPR render after these changes (or select IPR > Update Shadow Maps).

Using Apply Fog in Post When using Apply Fog in Post, the results cannot be seen in IPR.

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5

Image quality and render speed The speed/quality tradeoff Producing rendered images always involves making choices that affect the quality (anti-aliasing and sampling) of the images, the speed with which they are rendered, or both.

Related topics ■

Anti-aliasing and flicker on page 154

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Artifacts on page 155

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Render speed on page 155

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Anti-aliasing and flicker

Jagged or stair-cased edges in pixel-based images or flickering surfaces in an animation are aliasing artifacts. Aliasing artifacts result from point sampling, a process used in all computer graphics applications that determines the information about each pixel. Aliasing artifacts can result at various stages during any rendering process. Anti-aliasing is the process of removing or reducing these artifacts. Because there are many kinds of aliasing, such as grainy surfaces, flickering, and jagged edges, there are as many approaches to controlling or fixing these problems. You can make adjustments to a number of settings to decrease or eliminate aliasing artifacts and flicker. See Reduce artifacts and flicker on page 157. Most solutions to control aliasing are time consuming and increase render times. Try to find the solution that gives you the best balance between image quality and performance.

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Artifacts

Artifacts can show up as unintentional blotches, bands or cross-hatches on surfaces. Textures can flicker or crawl on surfaces from frame to frame during animations.

Clipping plane artifacts Especially in large scenes that have objects close together, background surfaces may appear to show through nearby surfaces. This is a result of how the camera’s clipping planes determine the depth position of geometry; the problem results from the limited precision used to store depth information. It is mainly influenced by the following camera parameters: near clip distance, far clip distance, and camera angle.

Render speed You can make adjustments to a number of settings to increase the speed with which the scene, surfaces, and, or shadows render, and the speed with which camera render the scene. To find out about strategies to increase rendering speed, see Increase overall rendering speed on page 158.

Reduce memory In some cases, you can also reduce the memory used by the render to decrease rendering times. See Reducing memory usage on page 163.

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Reduce file size (Maya Vector renderer) Complex scenes and certain Maya Vector Render Settings can produce very large SWF or SVG files that are unsuitable for online delivery. If you are using the Maya Vector renderer to create SWF or SVG files for online delivery, you can modify your scene and adjust the Maya Vector Render Settings to produce the best compromise between image quality and file size. See Strategies to decrease vector render file size on page 165.

Maya render diagnostics The Render Diagnostics tool lets you monitor how well you optimize the scene for rendering and watch for limitations and potential problems that may occur. For example, surfaces that are far away or blurred may not require the same level of visual accuracy or photo realism as surfaces close to the camera. You can speed render times and reduce memory usage if you know what the renderer is doing. Run Render Diagnostics after you adjust objects and before you render to obtain valuable information about how you can improve performance and avoid limitations. You can run the diagnostics while experimenting with rendering settings, or before you start the final rendering.

Hardware render diagnostics Hardware render diagnostics traverse the shading network and geometry to flag those features which are not supported in the same way as they are in software rendering. Render diagnostics also examines your graphics hardware to determine its level of support.

Related topics ■

Run diagnostics on page 166

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mental ray for Maya diagnostics on page 197

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mental ray for Maya error handling and diagnostics on page 251

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Improve rendered image quality Adjust scene anti-aliasing parameters (Maya software) Maya separates edge aliasing parameters from shading aliasing parameters to give you more control over image quality and performance. You can adjust anti-aliasing settings for edges, shading, multipixel filtering, and motion blur in the Anti-Aliasing Quality section in the Quality tab on page 415 of the Render Settings: mental ray tabs on page 404. For details on the settings, see Adjust anti-aliasing on page 93.

Adjust per-object anti-aliasing parameters Maya software rendering You can correct the flickering of very small objects by increasing the visibility samples in the selected object’s Attribute Editor.

Reduce artifacts and flicker Unlike anti-aliasing techniques, you cannot adjust the settings in the Render Settings window on page 376 to reduce artifacts and flicker. Instead, you can fix shadow artifacts, clipping plane artifacts, or animation flicker independently.

Shadow artifacts (Maya software rendering) Raytraced shadows are susceptible to the terminator effect, a self-shadowing error that results from tessellation (triangles that approximate a smooth surface). To fix raytraced shadow artifacts, increase the tessellation. For more information on tessellation, see Introduction to Tessellation and Approximation on page 39.

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Clipping plane artifacts (Maya software rendering) Clipping planes help Maya to determine how far and near objects are relative to the camera. By default, cameras have Auto Render Clip Plane turned on so that Maya can sort geometry as accurately as possible. If objects seem to inter-penetrate each other, turn off Auto Render Clip Plane and set the Near Clip Plane to 1.0. For more information on clipping planes and these settings, see Clipping planes on page 21.

Animation flicker For Maya software rendering and Maya hardware rendering. During rendering, Maya filters textures. If textures flicker or crawl along objects in your scene from frame to frame, consider using a lower resolution file texture, or, if you are not using a file texture, adjust the Filter settings in the Effects section of the texture’s Attribute Editor. For more information about texture filtering, see Texture filtering in the Shading guide.

Increase render speed Increase overall rendering speed To make a scene render faster, do any of the following: ■

Diagnose the scene to find ways to render the scene faster using Render > Run Render Diagnostics. You can use this tool to monitor how well you optimize the scene and to search for limitations and potential problems that may occur. For more information on render diagnostics, see Run diagnostics on page 166.

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Perform scene optimizations: ■

to turn options on or off to Click File > Optimize Scene Size > optimize everything in the scene and to remove unused or non-valid elements. See File > Optimize Scene Size in the Basics guide for more information about this window.

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■

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For Maya software rendering, use Block ordered texture set up. See Cache texture tiles using BOT (block ordered texture) on page 163.

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If the scene contains objects with construction history and you no longer need it, delete it. See the Construction history in the Basics guide for details.

Avoid memory swapping by: ■

Closing all applications before rendering to maximize the amount of memory available for rendering (including Maya if rendering from a shell or command line).

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Setting the TEMP or TMPDIR variable as the location for temporary render cache files: -TMPDIR (Linux) or - TEMP (Windows and Mac OS X) to make plenty of room for temporary rendered files. Make sure that the value of those variables points to a local, fast hard drive, not a network drive.

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For Maya software and mental ray for Maya, Test Resolution (Render > Test Resolution) lets you select a reduced resolution to test render the scene. For more information on test rendering strategies, see Visualize interactively with IPR on page 123.

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For Maya software, if the scene contains several identical surfaces (for example, multiple spheres), use Optimize Instances in the Render Settings: Maya Software tab on page 388 to improve rendering performance.

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Turn off motion blur if you don’t need it (the Vector renderer has no motion blur). For the Maya software renderer, use 2D motion blur instead of 3D motion blur when possible. See 2D Motion Blur global attributes and 3D Motion Blur in the Render Settings window on page 376 for details.

Related topics ■

Use average BSP (mental ray for Maya) settings on page 248

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Increase surface rendering speed Do any of the following: ■

Use single-sided instead of double-sided surfaces (which is the default) on the object’s Attribute Editor. The biggest speed gain is for the Maya hardware renderer.

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Tessellating large surfaces requires a lot of memory, so use several small surfaces instead of one large surface when you can. The renderer is more efficient with smaller surfaces.

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For Maya software rendering and Maya hardware rendering, use bump mapping instead of displacement mapping.

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For Maya software rendering, make bump maps flatter. To do this, reduce the value of the Alpha Gain attribute, which smooths the bump map and reduces the number of samples of adaptive shading. This technique only works when Edge Anti-aliasing is set to Highest Quality. The texture bump looks flatter when the Alpha Gain is lower.

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For Maya software rendering, turn on Use Displacement Bounding Box when using displacement maps.

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For Maya software rendering, use layered textures when possible, instead of a Layered Shader. (See Layered shaders and 2D and 3D textures in the Shading guide for details.)

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For Maya software rendering and mental ray for Maya, if you are raytracing the scene, set the Reflection Limit and Refraction Limit to the lowest values that produce acceptable results.

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For Maya software rendering, in the Render Settings: Maya Software tab on page 388 on Linux, Use File Cache avoids re-tessellation of the same surface during rendering. Turn on Use File Cache to store geometric data in a separate file in a location that you specify (the default location is /usr/tmp, but you can set a new location by typing setenv TMPDIR xxx, where xxx is the name of the directory where this file is output).

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Increase shadow rendering speed To make shadows render faster 1 Do any of the following: ■

For Maya software and mental ray for Maya, use depth map shadows instead of raytraced shadows.

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For surfaces that do not need to cast shadows, turn off Casts Shadows.

To make depth map shadows render faster 1 Do any of the following: ■

Set the Resolution to the lowest value that produces acceptable results. (For shadow casting spot lights, first reduce the Cone Angle to the lowest value that produces acceptable results.)

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Turn on Use Auto Focus (or set the Focus to the lowest value that produces acceptable results. See Focus, Width Focus) and set the Resolution to the lowest value that produces acceptable results.

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For Maya software rendering, set the light’s Filter Size to the lowest value that produces acceptable results. A Filter Size value of 2 or more is usually sufficient. For mental ray for Maya, adjust the Resolution, Samples, and Softness settings under the light’s Shadow Map Overrides section.

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For Maya software rendering, Set Fog Shadow Samples to the lowest value that produces acceptable results.

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For Maya software rendering, set Disk Based Dmaps to Reuse Existing Dmap(s).

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For Maya software rendering, if a point light does not have to produce shadows in the light’s positive or negative X, Y, or Z directions, turn off the appropriate attributes in the Depth Map Shadow Attributes section: Use X+ Map, Use X- Map, Use Y+ Map, Use Y- Map,, Use Z+ Map, or Use Z- Map.

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For Maya software rendering, if the scene contains NURBS surfaces, in the Memory and Performance Options section of the Render Settings: Maya Software tab on page 388, make sure Reuse Tessellations is on (the default setting).

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To make raytraced shadows render faster (for Maya software rendering and Maya hardware rendering) 1 Do any of the following: ■

If the Light Radius (or the Light Angle for directional lights) is greater than 0, set Shadow Rays to the lowest value that produces acceptable results. See Shadow Radius, Light Radius, Light Angle for details.

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Set Ray Depth Limit to the lowest value that produces acceptable results.

Increase camera views render speed For Maya software rendering. You can make camera views render faster by not selectively focusing the camera, or by selectively focusing the camera so more objects are in focus. To make camera views render faster 1 Turn off Depth Of Field, or increase the F Stop.

Global illumination and caustics Specify objects to participate in global illumination and caustics By default all objects participate in photon tracing for global illumination and caustics. Typically, not all are required for you to achieve the look you want. You can specify exactly which objects cast and, or receive photons to reduce the rendering load.

Final Gather Final Gather is view dependent and is recalculated for each frame in a sequence. You can store final gather results so that later frames can use the results from a frame rendered earlier to speed up the Final Gather rendering process.

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Reduce render memory usage Reducing memory usage To reduce the memory used by the renderer, perform the following pre-render optimizations to produce a smaller and more efficient file. ■

Cache texture tiles using BOT (block ordered texture) on page 163

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Delete information not relevant to the renderer on page 164

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Render parts of a scene separately on page 164

Cache texture tiles using BOT (block ordered texture) For Maya software rendering only. For more information on file textures, see File textures in the Shading guide. When you render, scripts, scenes, textures, and so on, are loaded into RAM. If all available RAM is used, the machine may hang or experience swapping problems. To reduce the load on RAM during render time, you can convert your textures to Block Ordered Textures (BOT), which are essentially tiles. (For more information on tileable images, see File textures in the Shading guide). With BOT files, a small cache of texture tiles are kept in RAM; when Maya needs more during render time, it goes to disk to find them. The BOT cache is a fixed amount of approximately 250KB in RAM and efficiently caches textures. BOT is not recommended for all texture files, but you notice the difference in speed when rendering high resolution textures.

Use the BOT pre-render setup A new and optimized scene file is generated and is ready for the renderer when you use the BOT pre-render setup. For more information, type the following: maya -optimizeRender -help

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maya -optimizeRender [options] mayaFile optimizedMayaFile

where mayaFile is the Maya file to be optimized and optimizedMayaFile is the name of the optimized Maya file. Use the following options: -botRes ‘int’

Resolution for which BOT files are produced. If this flag is not used, a default botRes of 512x512 is used.

-botLoca ‘name’

Directory in which BOT files reside (default is in the same directory as the original file).

-help

Prints the help message.

-noBOT

Avoid BOT creations.

-noCleanup

Avoid cleaning up non-rendering related data.

Delete information not relevant to the renderer You can reduce memory in the Maya file by deleting information not relevant to the renderer. Sometimes extra information is only needed when editing the scene, or it contains currently unused items saved for future uses.

Render parts of a scene separately You can render parts of a scene separately and composite the rendered images. For more information on rendering in layers and passes for compositing, see Render layer overview on page 68 and Render passes on page 80.

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Decrease file size (Maya Vector renderer) Strategies to decrease vector render file size If you are using the Maya Vector renderer to create SWF or SVG files for online delivery, you may need to modify your scene and adjust the Maya Vector Render Settings to produce the best compromise between image quality and file size. Complex scenes and certain Maya Vector Render Settings can produce very large SWF or SVG files that are unsuitable for online delivery. If you are using the Maya Vector renderer to create SWF or SVG files for delivery via CD-ROM, DVD, or network, or to create AI, EPS or bitmap images, then you do not need to be as concerned about file size. Use the following guidelines as a starting point to help you reduce the size of rendered SWF and SVG files. See Render Settings: Maya Vector tab on page 459 for more information on how the various options affect file size. Do any of the following: ■

Reduce the complexity of your scene: Consider removing minor elements of your scene. Reduce the number of triangles in polygonal and subdivision surfaces. Reduce the tessellation of NURBS surfaces.

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Reduce the number of frames in an animation.

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Reduce the Frame Rate of an animation.

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Choose an appropriate Fill Style based on the objects in your scene. Some fill styles produce results of equal quality, but different file sizes, for certain types of objects. Avoid using Full Color or Mesh Gradient as they always create large files.

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Turn on Combine Fills and Edges (SWF only).

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Increase the Curve Tolerance value.

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Set Svg Animation to HTML Script (SVG only).

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Turn on Compress (SVG only).

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Decrease the Detail Level.

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Set Edge Style to Outline instead of Entire Mesh. (For more edge detail, turn on Edge Detail.)

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Turn off Hidden Edges.

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Turn off Show Back Faces. If a surface does not render because it is facing away from the camera, manually reverse the surface’s normal.

Diagnose scene problems Run diagnostics To run render diagnostics 1 Do either of the following: ■

From the main Maya window, select Render > Run Render Diagnostics.

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From the Render View window, select File > Render Diagnostics.

Maya opens the Script Editor and displays a list of potential problems in the scene.

Related topics ■

Maya render diagnostics on page 156

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mental ray for Maya diagnostics on page 197

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mental ray for Maya error handling and diagnostics on page 251

Sample diagnostic messages The following are some of the diagnostic messages Maya software rendering displays: ■

Motion blur and raytracing are both turned on. (Reflections, refractions and shadows are not motion blurred.)

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You have motion blur turned on. Be aware that particles, lights and shadows do not motion blur. As well, motion blurred shadows may produce artifacts.

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You have specified output to the Quantel format. In previous versions of Maya, this format only outputs to NTSC/PAL/HDTV resolutions, and does not output to fields. If the above restrictions are not met, rendering defaults to IFF image output.

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You have specified output to the Cineon format. This format does not render out a mask channel.

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You have specified a fractional animation by-frame step. This results in images over-writing each other for fractional frame counts. Please remember to turn on the modify-extension.

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Near/far clipping values are too far apart. You may encounter numerical imprecision resulting in incorrect renders.

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There are no renderable cameras in the scene.

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Network rendering

6

Overview of network rendering Network rendering is the distribution of the rendering process across more than one machine (sometimes called a render farm). For example, you can divide an animation into smaller sequences and render each sequence on a different computer. You can also control when and on which computer to render. Rendering across a network of computers is often referred to as distributed rendering. Using Maya, there are three ways to set up network rendering. ■

Maya network rendering (see Managing Maya network rendering on page 170)

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mental ray network rendering (see mental ray network rendering: Satellite and standalone on page 199) ■

mental ray for Maya Satellite network rendering

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mental ray standalone network rendering

Related topics ■

Network render with mental ray for Maya on page 252

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Network render with Maya software on page 171

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Network render with mental ray for Maya on page 252

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Maya network rendering Managing Maya network rendering You can manage Maya network rendering in two ways: ■

Manually. See Network render with Maya software on page 171.

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Automated, provided by a third-party solution.

Computer preparation Maya network rendering requires a network of properly configured computers. TIP Maya network rendering may read and write numerous files over the network simultaneously. Make sure your network bandwidth can handle the traffic. Consider rendering files locally on each render node, then transferring them to the final destination.

File Access All files, scenes, and textures you use must be stored in locations accessible to each render workstation. This can be achieved by doing either of the following: ■

Providing the files to all the render workstations from a central file server. File permissions must be adjusted for your environment.

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Transferring the files to each render workstation’s local storage.

Plug-ins Make sure all render workstations used to render a scene containing plug-ins have those plug-ins installed, and that each render workstation has a valid license for those plug-ins. If a render workstation does not have a license for a plug-in being used, you may find that every frame it processes fails. TIP Cache data in the scene to prevent unwanted differences between frames, computers, effects, and so on.

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NOTE There are numerous third-party solutions that provide solutions for network rendering. This guide gives a minimum workflow only. Please check our Conductor Partners for available solutions.

Network render with Maya software Before you begin, you must have networked workstations. See your system administrator if workstations are not networked. To render on several computers 1 Install Maya on each machine. We recommend that you pare down the installation to the minimum requirements. For instance, you do not have to load all options on each machine when installing (for example, documentation). 2 Initiate render commands on each render workstation. This can be achieved manually by the Command Line Render command. To automate it, use simple scripting capabilities. See the Command Line Render Help (render -h) for more options. For example, If you have a 100-frame scene and want to distribute the rendering across 4 render workstations, type: Render -s 1 -e 25 filename for the first render workstation. Render -s 26 -e 50 filename for the second render workstation. Render -s 51 -e 75 filename for the third render workstation. Render -s 76 -e 100 filename for the fourth render workstation.

TIP Using -rep You can use the -rep flag on the Render command to automate Maya software networked rendering.

Related topics ■

Overview of network rendering on page 169

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About the mental ray renderer About the mental ray for Maya renderer mental ray for Maya offers all the features traditionally expected of photorealistic rendering and includes functionality not found in most rendering software. mental ray for Maya allows interactive and batch mental ray rendering from within the Maya user interface. With the help of built-in shaders supporting almost any effect available in Maya, mental ray for Maya allows the rendering of scenes created within Maya or their export into the mental images file format (.mi). (For detailed information on the mental ray standalone application, see the mental ray reference User Manual and the mental ray Shaders Guide, available from the Maya help.) After you load the mental ray plug-in (and select mental ray as the renderer), the Render menu lists available menu items for mental ray for Maya. As well, the Attribute Editor contains a mental ray section in which you can edit attributes that are used exclusively when rendering with mental ray for Maya. To load the mental ray for Maya plug-in, see the note in Select a renderer on page 11.

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IFF File format The IFF image support in mental ray permits both color and depth information written into a single file. This requires the proper parameters to be set in the Render Settings (Depth Channel [Z Depth] in the File Output section must be turned on).

File Export mental ray for Maya can also be used in Maya as a file exporter. When you export a Maya scene file to the proprietary mental images (.mi) file type, the file export simply writes a .mi file to disk with the given name. Additional options are available in the user interface to control ASCII or binary mode export and file-pre-frame creation for animations. See Exporting .mi files on page 186.

Geometry Types Maya supports three types of geometry: polygonal (Polygon Mesh), free-form objects (NURBS curves/surfaces), and subdivision surfaces.

Known differences The native Maya and mental ray renderers may produce different results in certain situations. For more details, see mental ray for Maya renders look different than Maya renders on page 278.

Shading Networks and Nodes A shading group in Maya defines the material, volume, and displacement shaders, along with the list of lights used in the illumination calculation for renderable objects. Such a shading group can directly be translated into a .mi material. For more information on mental ray for Maya shaders, see mental ray for Maya shaders in the Shading guide.

Global illumination, Caustics, Final Gather, and HDRI For information and procedures, see Indirect (global) vs. direct illumination in the Lighting guide.

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Global illumination mental ray for Maya can render with Global illumination, the technique used to capture indirect illumination (the natural phenomenon where light bounces off anything in its path until it is completely absorbed).

Caustics mental ray can render with Caustics, the light effects that caused by specular reflected or refracted light, like the shimmering light at the bottom of a pool of water.

Final gather mental ray for Maya can render with Final gather (a method of global illumination) to create very (or purely) diffuse scenes where the indirect illumination changes slowly.

Support for HDR images mental ray for Maya supports HDR images as file textures.

Direct light with mental ray for Maya Area Lights The main purpose of area light sources is to generate more realistic lighting, resulting in soft shadows. This is achieved by using one of four primitives (rectangles, discs, spheres, and cylinders) as light sources with nonzero area. For more information about mental ray for Maya areas lights, see Default lighting in Maya in the Lighting guide.

Scene rendering Parallelism mental ray for Maya supports both host and network parallel rendering. It renders identical output on all common and widely-used platforms. For network rendering, it performs best in a client-server setup, where it takes care of load balancing and network communication reduction. For information on mental ray for Maya network rendering, see Network render with mental ray for Maya on page 252.

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Animations When rendering animation files or previewing animations inside Maya, mental ray for Maya exploits incremental changes. This means it determines if scene elements actually have changed between frames and just processes those changes, thus accelerating the render cycle. The check is based on Maya information and includes both geometry (plus instances) and shading nodes. If no changes are detected, the corresponding object or shader is not updated in subsequent frames and appear animated. Incremental changes are not used if animations are exported as file per frame.

mental ray object rendering flags You can control how particular objects contribute to certain rendering stages by setting per-object rendering flags in the object’s Attribute Editor.

Motion Blur For information about mental ray for Maya motion blur, see mental ray for Maya motion blur on page 180.

Customizations (For mental ray advanced users only.) The Custom Text Editor can be used to create and attach custom text to certain scene entities. This replaces the internally created .mi output with the custom text. Using the Custom Text Editor you can integrate custom mental ray shaders into Maya. To use the Custom Text Editor, see Custom mental ray text the Shading guide. mental ray for Maya checks and reads special custom attributes on certain Maya nodes and uses them for customized scene processing. Additionally, it adds its own custom nodes to Maya for convenient handling of mental ray extensions. All of these customizations are located in the Custom Entities section of the Render Settings window on page 376. For descriptions of the mental ray for Maya Custom Entities attributes, see Render Settings: mental ray tabs on page 404, Options tab on page 444.

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WARNING To reduce the potential of unpredictable results, the processing of such entities is disabled by default for the integrated preview rendering in Maya. Turn on Custom Entities at your own risk. It is, however, enabled for the .mi file export to create customized scene files for external rendering.

Custom mental ray text mental ray for Maya supports a method to produce custom text in the output stream written to the .mi file. This is for text-only integration of custom mental ray shaders within Maya; it allows for the creation of special-purpose Maya nodes that hold customized mental images (mi) text.

Custom vertex data mental ray for Maya checks Maya polygonal meshes for additional dynamic (custom) attributes that supply per vertex data. This data is exported as additional mental ray texture spaces for shader access. For more information about custom vertex data, see Custom vertex data in the Shading guide.

Error handling and diagnostics mental ray for Maya checks for errors in a Maya scene and recognizes various operating system errors. You can use diagnostics to help you diagnose issues with samples and photon maps. For more information on mental ray for Maya diagnostics, see mental ray for Maya error handling and diagnostics on page 251.

mental ray specific image formats The following image formats are unique to the mental ray renderer. ■

mentalray Color (ct)

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mentalray Alpha (st)

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mentalray Normal (nt)

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mentalray Motion (mt)

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mentalray Depth (zt)

About the mental ray for Maya renderer | 177

■

mentalray Tag (tt)

■

mentalray Bit (bit)

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mentalray HDR (cth)

Rendering Color and Z-depth The following is true when rendering to a format other than Maya IFF or RLA. If rendering to Maya IFF or RLA, all channels RGBAZ are written to one file. For all other image formats, when the Depth Channel (Z depth) option is enabled in the mental ray Render Settings, mental ray will write out a separate image file containing depth information. Z-depth is now written out in IFF format and rendered to a separate file that has “Depth” as a suffix to the image name, for example, imageDepth.#.iff.

Limitation Hyperthreading can slow down mental ray rendering The mental ray IPR and the Auto Render Threads on page 320 option in Render > Render Current Frame > and Render > Batch Render > do not distinguish between dual core CPU's and hyperthreading. Therefore, these options report all virtual CPU's as available threads. Workaround 1: Turn hyperthreading off. Workaround 2 (for Auto Render Threads on page 320 option): Turn off Auto Render Threads on page 320 and reduce the number of threads by 1/2.

Unsupported features mental ray for Maya does not support the following Maya rendering features: ■

Keyframing or set driven keyframing on the RGB components of a ramp shader’s colorEntryList (the list of colors that comprise the ramp shader) are unsupported.

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postprocessing effects: Paint Effects, light glow, optical effects, and 2d motion blur

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Field Rendering

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The -hardware_echo flag is not supported through the command line.

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Unsupported File Texture Formats The following file texture formats are currently unsupported by mental ray for Maya: ■

AVI files

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Maya BOT files

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certain variants of the TIFF format (those with LZW compression, including those generated by the Maya renderer)

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Cineon CIN files

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EPS files

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GIF files

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IFF16 files

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Wavefront-alpha files Workaround (TIFF,CIN,GIF) For these unsupported file formats, Maya's imgcvt image conversion tool can be used to convert the files to a supported format such as IFF or RGB. For a complete list of file texture types supported by mental ray, see the Rendering with mental ray Handbook. (BOT) There is currently no workaround that will allow Maya BOT files to be used in conjunction with mental ray for Maya. mental ray does support its own memory-mapped map file texture format, however. Standard image files can be converted to this format using the imf_copy command: imf_copy -p .rgb .map

See the Rendering with mental ray Handbook for a full description of memory-mapped textures in mental ray.

Related topics ■

Introduction to rendering on page 1

■

Hardware, software, and vector rendering on page 2

About the mental ray for Maya renderer | 179

Motion Blur mental ray for Maya motion blur In mental ray for Maya, you can choose between No Deformation and Full Motion Blur. Motion Blur in mental ray for Maya blurs everything: shaders, textures, lights, shadows, reflections, refractions, and caustics. The No Deformation mode results in instance motion; shape changes are not considered. The Full Mode additionally exports motion vectors for every vertex of the moving object. Use it to motion blur objects with deforming shape. This mode requires more translation and render time. The No Deformation mode just exports instance motion performed on transform nodes, any shape changes (even linear movements) are not considered. The Shutter Open, Shutter Close on page 426 setting of the Maya camera determines the actual motion blur path length. You can modify other settings, such as Motion Blur By on page 426, to further control the final motion blur calculation. Find these settings in the Motion Blur on page 394 (in the Render Settings window on page 376). A typical application of motion blur is the Export Motion Segments on page 449 option, which approximates any non-linear movement with a set of linear segments. NOTE Any transformation animation (instance translation, rotation etc.) with non-linear properties is not handled by the plug-in (there is no support in mental ray for more than 1 motion transform) but left to mental ray's built-in procedure to detect common cases of rotations (even pivot rotations) automatically. More complex transformation animation is not supported natively, but may be baked as shape deformation in Maya to be rendered correctly.

Related topics ■

Motion blur on page 16

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Approximation in mental ray for Maya Approximation Approximation (called tessellation in Maya; see Introduction to Tessellation and Approximation on page 39) is the process mental ray for Maya uses to convert NURBS surfaces (or displacement mapped polygon meshes) to triangles. Triangles determine how smooth an object looks at closer distances to you (the camera). When poorly tessellated objects are close to the camera, they appear faceted; when they are further away, they don’t. When rendering with mental ray for Maya, a set of approximation settings must be specified for each piece of geometry. By default mental ray for Maya derives approximation settings from Maya’s tessellation settings. This produces results close to the look of Maya software rendered scenes, and is useful for those familiar with the behavior of those settings. Alternatively, you can specify approximation settings more precisely for mental ray for Maya by using an approximation node. NOTE The tessellation of a subdivision surface is controlled by subdivision approximation only, regardless of whether the subdivision surface is displacement mapped.

Derive from Maya (default approximation) settings If only Basic tesselation (see Primary vs. secondary tessellation passes on page 40) is used, mental ray for Maya bases tessellation on the Curvature Tolerance attribute setting of the NURBS surface. If the Advanced tessellation attributes are used but none of the secondary tessellation controls are active for an object, Parametric approximation is derived from Maya's primary tessellation controls. Otherwise, mental ray for Maya’s LDA approximation method is applied with values calculated from Maya secondary tessellation controls. Primary tessellation creates a base triangulation, which is further tessellated until the secondary set of conditions are met. mental ray for Maya’s Parametric approximation method is comparable to Maya’s primary tessellation; the length/distance/angle (LDA) method is comparable to Maya’s secondary tessellation.

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Approximation nodes Approximation nodes give you more precise control over all of mental ray for Maya approximation features, some of which Maya cannot access. For example, you can use Approximation nodes to specify separate tessellation settings for surfaces, trim curves, and displacement maps. As an example, consider a simple flat NURBS surface with a complex trim curve. For such a case, you would specify a low-quality surface approximation in conjunction with a high-quality trim curve approximation. mental ray would then ensure that the surface is approximated with only a few triangles except around the trim curves, where many triangles would be used to ensure a smooth edge. The same analogy applies to a simple surface with a complex displacement map. For that case, you might apply a low-quality regular surface approximation in conjunction with a high-quality displacement approximation, to ensure that triangles are added only to areas where they are needed to capture the complexity of the displacement map. This node type... Does this...

To only this type of geometry...

Surface Approximation

Determines how NURBS surfaces are tessellated into triangles for rendering.

NURBS surfaces

Trim Curve Approximation

Controls the tessellation of trim curves on NURBS surfaces.

NURBS surfaces with trim curves

Displacement Approximations

Controls the tessellation of displacement maps on a surface. Whereas ordinary Surface Approximations only tessellate based on the underlying surface, Displacement Approximations additionally take into account features of the displacement map when tessellating.

NURBS or polygonal surfaces with displacement maps

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This node type... Does this...

To only this type of geometry...

Subdivision Approximation

polygonal surfaces

Control render-time smoothing of polymesh surfaces.

NOTE ■

Subdivision surfaces are supported by mental ray versions prior to 3.2, when the mental matter library libmisubdiv.so is linked in. mental ray 3.2 and later includes subdivision surface rendering (but not modeling) support, and do not require an external library.

■

For best performance, when using subdivision approximation, use triangles and quads or a combination of both.

Approximation styles An approximation style is the general subdivision scheme mental ray for Maya uses to break the surface into triangles. Some approximation styles work by repeatedly cutting the entire surface from end to end, while others are capable of adding triangles in a more localized fashion. mental ray for Maya provides a few standard approximation styles (Grid, Tree, and Delaunay) and the Fine approximation style. The standard approximation styles use as few triangles as possible to approximate a surface to achieve the quality you define in the approximation settings.

Fine approximation Fine approximation subdivides very complex surfaces (especially detailed displaced surfaces) into a large number of roughly uniformly-sized small triangles in order to guarantee a smooth result. To deal with the large number of triangles mental ray for Maya breaks the surface up into independent sub-objects that are each tessellated and cached separately, generating the triangles without consuming excessive amounts of memory. This approximation style only supports the Spatial approximation on page 210 method, which specifies the size of triangles to be generated.

Approximation styles | 183

NOTE Fine approximation cannot be used together with merging and connections (that is, when surfaces are stitched, there may be holes along the stitch). Geometry type

Can I use Fine approximation?

polygon displacement

yes

NURBS surface displacement

yes

subdivision surface displacement

yes

NURBS surface approximations

yes

curves

no (because they are not tessellated to triangles)

How Fine Approximation works To allow for Fine approximation, the granularity of mental ray for Maya’s cache manager is reduced, whereby smaller units are formed by splitting objects into smaller sets. These sets can be individually tessellated without excessive memory requirements. Fine approximations support a small subset of approximation techniques since the other styles exist only to trade off triangle counts vs. quality, which is no longer a problem for fine approximations.

mental ray for Maya geometry types Maya supports three types of geometry: polygonal (Polygon Mesh), free-form objects (NURBS curves/surfaces), and subdivision surfaces.

NURBS (free-form curves and surfaces) Free-form NURBS curves and surfaces in Maya are supported by mental ray for Maya. These surfaces, which can have a boundary and several holes, are expressed as trim and hole curves in the mental images surface definition.

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Polygonal meshes Maya polygonal meshes are exported as mental images polygon objects and support features like vertex sharing, holes, and displacement refinement. Displacement mapping can be applied to meshes. The special displacement properties for polygon surfaces are controlled in much the same way as NURBS surfaces. Polygonal meshes that consist only of triangles or quadrangles can be exported as a subdivision surface base mesh for mental ray rendering. To export a polygonal mesh for rendering, you must create and attach a Subdivision approximation node to the mesh. This node lets you further control the subdivision process and quality. Additionally, you can create and attach a Displace Approximation node to support the displacement of the mesh. If mental ray for Maya encounters a Subdivision approximation node, it is exported as a mental images subdivision surface base mesh (including textures and motion vectors, but without normals) instead of a simple polygonal mesh. If the conversion fails (because other than triangles/quadrangles were found), an error message is printed and the mesh is exported as usual.

Subdivision surfaces Maya’s subdivision surfaces are supported in mental ray for Maya as long as the base mesh is made up of only quads. The support for subdivision surfaces includes hierarchical edits, hierarchical material assignments, edge and vertex full creases only, uncreases, texture reference objects, deformation motion blur, and derivatives (for bump mapping and texture filtering). Unlike Maya, however, mental ray for Maya can handle only quadrilateral base meshes (a number of Maya standard subdiv shapes are therefore rejected), and UV coordinates can only be specified on the base mesh (level 0). To prepare subdivision surfaces not directly supported (for example, where the base mesh does not contain only quads), see Obtain quads for subdivision surfaces on page 207. NOTE The tessellation of a subdivision surface is controlled by subdivision approximation only, regardless of whether the subdivision surface is displacement mapped.

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Visualize and render images Command line render You can render from a command line if you want to render an animation or single frame. Advantages include the following: ■

works with single images and animation

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uses less memory than having all of Maya (UI) running

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can be scripted

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can be integrated into a rendering pipeline (render farms)

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for Maya software rendering, you can override render settings using command flags (for other renderers, you must also write a MEL script)

For more information, see Command line renderer in the Rendering Utilities guide.

mental ray for Maya command line options The following mental ray for Maya command line options are supported during IPR: -rg/region Update the IPR region to the selected one. -rr/regionRect Set a new IPR region explicitly (works together with -region). -pt/pauseTuning Controls actual rendering of IPR requests, shader changes are always recognized in all cases. -q -imr Returns true (1) if IPR is active.

Exporting .mi files Scene Export Optimization Controls Several controls let you manually optimize the process of exporting scenes to .mi format. The translator recognizes a specific set of dynamic attributes that you can add to nodes to control how they are exported.

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To export a .mi file, see Export a .mi file and render with mental ray on page 241. You can accelerate the process of exporting scenes to .mi format by disabling deformation checking for objects that are known to be static over an animation (buildings, for example), and by disabling tangent vector export for objects that do not use bump mapping or other tangent-based shading effects. miDeformation Controls whether or not the translator tries to detect deformation of an object. To support per-object control of deformation determination and motion vector calculation of shape nodes, this dynamic attribute of type boolean is recognized. It overrides the global Export Shape Deformation option and either marks the current shape for or excludes it from deformation motion blur. Two common scenarios are supported: ■

disable deformation globally but enable it for specific shapes

■

enable deformation globally but disable it for specific shapes

This option may accelerate translation of shape animations and detection of deformation motion blur dramatically. miTangents Controls export of tangent vectors on objects. To support per-object control of tangent vector calculation for polygon meshes and NURBS surfaces, this dynamic attribute of type boolean is recognized. It overrides the global Export ... Derivatives options and marks or ignores the current shape accordingly for tangents computation. Two common scenarios are supported: ■

disable tangents globally but enable them for specific shapes

■

enable tangents globally but disable them for specific shapes

The tangents are first order derivatives supplied as mental ray bump basis vectors. They are required for mayabase shader filtering and bump mapping purposes.

Multi-render passes

Multi-render passes | 187

Overview Multi-render passes reduce the need to use render layers, thus reducing compute times for scene translation and rendering. If you work with complex multi-layered compositions, rendering may also be several times faster. Using multi-render passes, you can render an unlimited number of render passes and group them into render pass sets. For advanced users, you can also select a subset of the objects or lights in your scene to contribute to each render pass. This subset is called a render pass contribution map. Render pass contribution maps allow you to perform scene segmentation at render time. NOTE The multi-render pass feature is supported for the mental ray renderer. The rendering API allows other 3rd party renderers and custom renderers to support it moving forward. Currently, the multi-render pass workflow is supported for the following shaders: ■

Anisotropic

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Blinn

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Lambert

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Phong

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PhongE

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Env Fog

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Fluid Shape

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Light Fog

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Particle Cloud

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Volume Fog

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Volume Shader

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Hair Tube Shader

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Ocean Shader

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Ramp Shader

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Hair

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Fur

■

Image Plane

■

Layered Shader

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Shading Map

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Surface Shader

■

Use Background

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mental ray mi_metallic_paint_x_passes, mia_material_x_passes, misss_fast_shader_x_passes shaders NOTE The mental ray mi_metallic_paint_x_passes, mia_material_x_passes, and misss_fast_shader_x_passes shaders only support object pass contribution map capabilities but not light pass contribution map capabilities. All lights in your scene contribute to a render pass for a pass contribution map that includes these shaders.

NOTE Standard surface materials support all render passes mentioned in Available render passes on page 191; however, there are some non-standard shaders which contribute only to a subset of applicable passes, such as volume shaders, hair, and fur shaders, and so forth.

Setting up your scene to use multi-render passes To set up multi-render passes, do the following: ■

Create render passes using the Passes tab in the Render Settings window and the Create Render Passes window. The Passes tab is available when

you select mental ray as your renderer. Click the New Pass button in the Passes tab to open the Create Render Passes window, and select the render passes that you want to create. See Create Render Passes window on page 470 for more information. ■

Use the Passes tab to associate render passes with each layer and each pass contribution map. See Passes tab on page 404 for more information.

Multi-render passes | 189

■

Use the render pass Attribute Editor to set your render pass options, such as the framebuffer type, or the number of channels for your render pass output. You can even create render pass presets. See Render pass Attribute Editor on page 501for more information.

■

Optionally, if you want to create several render passes, you can group them into a render pass set. Create a render pass set using the Passes tab in the Render Settings window. See Passes tab on page 404 for more information.

■

Use the Relationship Editor to manage the membership of your render pass set. Select Window > Relationship Editors or click in the Passes tab. See Relationship Editor for more information.

Related topics ■

Introduction to multi-render passes: a simple workflow example on page 218

■

Sample workflow for multi-render passes on page 224

Render pass contribution maps A render pass contribution map associates a subset of lights and renderable objects in your scene with one or more render passes. For example, if your render layer consists of 5 objects and 2 lights, you can create a diffuse pass, an ambient pass, and a specular pass for only 3 of the objects and 1 of the lights. ■

Create a render pass contribution map that contains the 3 objects and the light. Select the objects and the light, then right-click the layer in the Render Layer Editor and select Pass Contribution Maps > Create Pass Contribution Map and Add Selected.

Alternatively, you can click the New pass contribution map button in the Passes tab in the Render Settings window. See Render Layer Editor on page 367 for more information. ■

Use the Create Render Passes window to create your render passes. See Create Render Passes window on page 470 for more information.

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■

Use the Passes tab in the Render Settings window to associate the render passes with your render pass contribution map. See Passes tab on page 404 for more information.

You can create multiple pass contribution maps for each render layer, or, share a pass contribution map between two or more layers. When rendering a given render layer, only the pass contribution maps linked to the layer are applied. Render passes that are not connected to any objects through pass contribution maps are implicitly associated to all objects. NOTE You can create the pass elements (pass contribution maps, passes, pass sets, and render layers) in any order.

Related topics ■

Render Layer Editor on page 367

Available render passes Choose from the following render passes: NOTE Occasionally, you may notice aliasing on the edges of your render passes that does not exist in your overall beauty pass. This occurs because the mental ray adaptive sampling algorithm only refines sampling in areas of high contrast in your main beauty pass and not your individual passes. For example, an edge that appears in a material pass, but not in a beauty pass, may be under-sampled. The aliasing does not appear in your composited image. However, you can smooth out the edges for your individual passes by enabling the Contrast All Buffers option in the Render Settings window, Quality tab so that the adaptive sampling algorithm analyzes the contrast in all color frame buffers being rendered, rather than for just the master beauty pass. Render Pass

Description

2D Motion Vector

Relative motion (in raster coordinates) of objects in your scene; in other words, how far each pixel is moving between two frames. Vector is expressed in normalized pixels.

3D Motion Vector

3D motion vector in world space. In mental ray for Maya, the 3D motion vector is expressed in internal space.

Multi-render passes | 191

Render Pass

Description

Ambient

Ambient contribution of the surface. In Maya, this is the material color multiplied by the ambient light color. See Render pass Attribute Editor on page 501 for more information on the attributes for this pass.

Ambient Irradiance

Amount of ambient light received by the surface. See Render pass Attribute Editor on page 501 for more information on the attributes for this pass.

Ambient Occlusion

Ambient occlusion contribution from both self ambient occlusion as well as primary ambient occlusion, which is derived from surrounding objects. You must enable Ambient Occlusion in the Render Settings: Features tab in order to use this render pass.

Ambient Material Color

Reflectivity of the material with respect to ambient light. See Render pass Attribute Editor on page 501 for more information on the attributes for this pass.

Beauty

Final color computed by mental ray for Maya. See Render pass Attribute Editor on page 501 for more information on the attributes for this pass.

Camera Depth / Camera Depth Remapped

Extracts the distance between the camera and the intersection point. Choose between normalized distance and real scene distance. See Camera Depth render pass attributes on page 503 for more information on the attributes for this pass.

Coverage

mental ray Coverage frame buffer. This frame buffer offers only silhouette coverage. Self-coverage is currently not supported.

Custom Color / Custom Depth / Custom Label / Custom Vector

Use in conjunction with the writeToColorBuffer, writeToDepthBuffer, writeToVectorBuffer, and writeToLabelBuffer shaders to write data to the framebuffer. Or, create your own custom pass if you are using custom shaders. See mental ray render pass utility shaders for more information.

Diffuse

Diffuse shading of material. See Render pass Attribute Editor on page 501 for more information on the attributes for this pass.

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Render Pass

Description

Diffuse Without Shadows

Diffuse pass without shadowing information. See Render pass Attribute Editor on page 501 for more information on the attributes for this pass.

Diffuse Material Color

Provides constant diffuse color or textured diffuse color, excluding light contribution. See Render pass Attribute Editor on page 501 for more information on the attributes for this pass.

Direct Irradiance

Direct light arriving at each sample location. See Render pass Attribute Editor on page 501 for more information on the attributes for this pass.

Direct Irradiance Without Shadows

Direct irradiance without shadowing information. See Render pass Attribute Editor on page 501 for more information on the attributes for this pass.

Glow Source

outGlow output of surface shaders; affected by pass contribution maps. See Render pass Attribute Editor on page 501 for more information on the attributes for this pass.

Incandescence

Additive color. See Render pass Attribute Editor on page 501 for more information on the attributes for this pass.

Incidence (Light/Normal)

Measures the difference between the direction of the light ray and the surface normal. If the surface normal is facing the light, this value is 1. If the normal is facing away from the light, the value is 0. Create a pass contribution map to isolate the light ray of your choice. If there is no pass contribution map in your scene, Maya performs its calculations based on the sum of all lights in your scene.

Indirect

Indirect lighting from final gather, global illumination, and caustics. See Render pass Attribute Editor on page 501 for more information on the attributes for this pass.

Light Volume

Extracts all light-centric volume effects, for example, a light cone volume effect. See Render pass Attribute Editor on page 501 for more information on the attributes for this pass.

Multi-render passes | 193

Render Pass

Description

Material Incidence (Camera/Normal)

Measures the difference between the direction of the camera ray and the surface normal. If the surface normal is pointing to the camera, this value is 0. If the normal is facing away from the camera, the value is 1. Any angle greater than 90 degrees is also translated to 1. If bump mapping is applied to the shading network, it will appear in this pass. See Render pass Attribute Editor on page 501 for more information on the attributes for this pass.

Material Normal (Camera Space / Object Space / World Space)

Interpolated surface normal. Choose from one of Camera space, Object space and World space. If bump mapping is applied to the shading network, it will appear in this pass.

Matte

The object's matte, excluding transparency/opacity. This pass serves as the render layer compositing mask. Should be solid white in areas where objects are intersected. Independent of transparency/translucency. See Render pass Attribute Editor on page 501 for more information on the attributes for this pass.

Normalized 2D Motion Vector

Relative motion (in raster coordinates) of objects in your scene; in other words, how far each pixel is moving between two frames. Pixel displacement is normalized to (0—1). Static objects are expressed with 0.5,0.5 values. See Normalized 2D Motion Vector render pass attributes on page 502 for more information on the attributes for this pass.

Object Incidence (Camera/Normal)

Similar to the Material Incidence (Camera/Normal) pass but does not support bump mapping.

Object Normal (Camera Space / Object Space / World Space)

Similar to the Material Normal (Camera Space / Object Space / World Space) pass does not support bump mapping.

Object Volume

Extracts all object-centric volume effects, for example, smoke that is contained in a glass object. Also includes volume particles, volume fur, and fluids. See Render pass Attribute Editor on page 501 for more information on the attributes for this pass.

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Render Pass

Description

Opacity

The object's opacity, which is derived from transparency/refraction. In compositing, the object's opacity can be controlled independently from the render layer matte. See Render pass Attribute Editor on page 501 for more information on the attributes for this pass.

Raw Shadow

Similar to the Shadow pass but calculated only with respect to the irradiance in the scene. See Render pass Attribute Editor on page 501 for more information on the attributes for this pass.

Reflection

Reflection results. Includes self-reflection, primary reflections, secondary reflections and environment reflections. See Render pass Attribute Editor on page 501 for more information on the attributes for this pass.

Reflected Material Color

The reflected color parameter of the material. Pure constant reflection color or textured reflection. Used as a reflection matte to determine where reflection would be revealed (colored and noncolored). See Render pass Attribute Editor on page 501 for more information on the attributes for this pass.

Refraction

Refraction results. Includes self-refraction, primary refraction, and environment refraction. See Render pass Attribute Editor on page 501 for more information on the attributes for this pass.

Refraction Material Color

The transparency color parameter of the material. Pure constant refraction color or textured reflection. Used as a refraction/transparency matte to determine where refraction is revealed (colored and non-colored). See Render pass Attribute Editor on page 501 for more information on the attributes for this pass.

Scatter

Scattering effects that result from the material’s scattering attributes (for example, Scatter Radius, Scatter Color). See Render pass Attribute Editor on page 501 for more information on the attributes for this pass.

Multi-render passes | 195

Render Pass

Description

Scene Volume

Extracts all scene-centric volume effects such as fog, layered fog, haze, and so forth. See Render pass Attribute Editor on page 501 for more information on the attributes for this pass.

Shadow

Pure shadow contribution for both self-shadowing as well as direct shadows. The shadow pass can be luminance or colored shadows. Takes into account material contributions. See Render pass Attribute Editor on page 501 for more information on the attributes for this pass.

Specular

Specular shading. The specular component is modulated differently depending on the type of material associated with the object. For example, Phong, PhongE, Blinn, and Anisotropic materials produce specular contributions differently. On a Phong material, the specular pass can be modulated using cosine power and specular color. See Render pass Attribute Editor on page 501 for more information on the attributes for this pass.

Specular Without Shadows

Similar to Specular but without shadow occlusions. See Render pass Attribute Editor on page 501 for more information on the attributes for this pass.

Translucence

Back shading contribution revealed on the front surface. See Render pass Attribute Editor on page 501 for more information on the attributes for this pass.

Translucence Without Shadows

Similar to Translucence but without shadows. See Render pass Attribute Editor on page 501 for more information on the attributes for this pass.

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Quality, render speed, diagnostics mental ray for Maya diagnostics mental ray supports a number of diagnostic modes that help you visualize and optimize the rendering process. They modify the output image to include grid lines or dot patterns that indicate coordinate spaces or sampling or photon densities. These graphs help you detect insufficient or excessive sampling densities, and tune parameters such as numbers of photons or sampling and contrast limits. For more information, see Diagnostics on page 251.

Related topics ■

Run diagnostics on page 166

■

Maya render diagnostics on page 156

Increase render speed by converting textures to optimized memory format

Converting textures to optimized format You can convert textures to an optimized format to increase rendering efficiency. Maya will automatically convert the textures in your scene file to an optimized format (.map). This feature makes good use of memory, allowing you to render larger scenes and render scenes with a higher resolution. This feature can also improve the performance of network renders. The conversion to the optimized format can be done before rendering begins, or, you can trigger the conversion by selecting the Update optimized cache textures now option in the Rendering Preferences. After the initial render, only newly modified textures will be re-converted. These optimized textures are only used for rendering. The original textures remain untouched and are still used for tasks such as interactive display, UV placement and so forth.

Quality, render speed, diagnostics | 197

Feature benefits ■

Optimized textures are stored at a customizable location for use elsewhere. For more information, see Optimized textures location in the Rendering Preferences window.

■

When used for network rendering, less data is sent across the network, reducing render times and network load.

■

Reduce memory usage so that you can render larger scenes and render scenes with higher resolution textures, such as 10k and above. WARNING If using network rendering, the optimized textures must be accessible on each slave and master machine. You can either store the file on a file server that is accessible by all machines, or, the file must be available locally on each slave machine.

About the optimized texture format The optimized texture format is an uncompressed format that offers multi-resolution capability, where each level being stored is formatted in a tile. There is no pixel being read when the texture is referenced in the scene. Only the tiles required for the render are loaded as necessary. Using the tileable format, multiple resolutions of the same image are stored and properly filtered. As a result, the optimized texture files are considerably larger than their original counterparts. NOTE ■

You can set the preferences for this feature by selecting Window > Settings/Preferences > Preferences. Under the Rendering section, select mental ray as your Preferred renderer. For more information. see Rendering preferences.

■

If the textures in your scene file are already of the .map format, then these files will still be converted and carried over to the cache location specified under Custom Location in the Rendering Preferences window.

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Network rendering Overview of network rendering Network rendering is the distribution of the rendering process across more than one machine (sometimes called a render farm). For example, you can divide an animation into smaller sequences and render each sequence on a different computer. You can also control when and on which computer to render. Rendering across a network of computers is often referred to as distributed rendering. Using Maya, there are three ways to set up network rendering. ■

Maya network rendering (see Managing Maya network rendering on page 170)

■

mental ray network rendering (see Network render with mental ray for Maya on page 252) ■

mental ray for Maya Satellite network rendering

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mental ray standalone network rendering

mental ray for Maya network rendering mental ray network rendering: Satellite and standalone mental ray network rendering allows you to distribute the rendering of each frame in your scene across multiple machines on your network. This requires mental ray rendering licenses, either mental ray for Maya Satellite or mental ray standalone. The mental ray for Maya plug-in that is integrated in Maya always lets you render on up to 4 local CPUs. With Maya® Complete™, mental ray satellite rendering can take place on 2 additional remote CPUs. With Maya® Unlimited™, mental ray satellite rendering can take place on 8 additional remote CPUs.

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The mental ray network rendering process can be invoked while working within Maya (in the Render View or batch rendering) or from the command line within Maya. A mental ray distributed rendering can speed up all of the following tasks: ■

interactive rendering (through the Maya interface)

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IPR rendering with mental ray for Maya

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interactive batch rendering (a batch render started by Maya)

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command-line rendering

Terminology When using mental ray for Maya and mental ray for Maya Satellite, master refers to the machine that is submitting the network render requests interactively, via batch or command line, and slave refers to an individual machine with mental ray standalone or mental ray for Maya Satellite on the network that receives and performs part of a network render and sends the information back to the client. Any machine with mental ray standalone can be a master, a slave or both at the same time. NOTE While it is not recommended, you can mix any combination of Linux, Windows, and Mac OS X machines as masters and slaves.

Related topics ■

What you need to set up network rendering on page 200

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Configuration files on page 201

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Network render with mental ray for Maya on page 252

What you need to set up network rendering mental ray standalone If you want to render Maya scenes (.mb or .ma) from within Maya or batch render with Maya, you need to install mental ray for Maya on all server machines and mental ray standalone on all slave machines.

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If you want to render native mental images (.mi) scenes from the command line using the mental ray standalone renderer, you need to install mental ray on all master and slave machines.

mental ray for Maya Satellite If you want to render Maya scenes (.mb or .ma) from within Maya or batch render with Maya, you need to install mental ray for Maya on all server machines and mental ray for Maya Satellite on all slave machines. You can use up to 2 CPUs (with Maya Complete) or 8 CPUs (with Maya Unlimited). For more information about installing mental ray for Maya Satellite, see the Installation and Licensing guide. You can’t render native mental images (.mi) scenes from the command line using the mental ray for Maya Satellite; you must use mental ray standalone.

Configuration files To specify which network render slave machines a master uses, mental ray for Maya and mental ray standalone use different configuration files: ■

mental ray for Maya and mental ray for Maya Satellite uses a file called maya.rayhosts

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mental ray standalone uses a file called .rayhosts

maya.rayhosts mental ray for Maya and mental ray for Maya Satellite look for maya.rayhosts in the following directories: ■

user’s Maya preference directory

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user’s Maya application directory

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user’s home directory

To configure maya.rayhosts files, see Set up a master machine with mental ray standalone (method 2) on page 258

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maya.rayrc mental ray for Maya looks for (maya.)rayrc in the following directories: ■

user’s Maya preference directory

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user’s Maya application directory

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user’s home directory

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$MAYA_LOCATION/mentalray

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directory from which the plug-in was loaded

maya.rayrc is installed with mental ray and additional configuration is generally not required.

mental ray for Maya reference links mental ray for Maya rendering menu items The following is a list of mental ray for Maya specific menu items. ■

File > Export All, Export Selection (mental ray) on page 309

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Window > Rendering Editors > mental ray > Approximation Editor on page 319

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Window > Rendering Editors > mental ray > Custom Text Editor on page 319

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Render > Render Using > mental ray on page 334

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To set clipping planes under Create > Cameras > Camera on page 313, see Clipping Planes on page 315.

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To set the number of rendering threads to be used by mental ray for Maya for rendering, see Render Threads on page 320.

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To create an image plane and attach it to the camera, Image Plane on page 353.

mental ray for Maya rendering Windows and Editors See mental ray Approximation Editor on page 363 for a description of the mental ray for Maya approximation editor.

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For information on the mental ray tabs in the Render Settings window, see: ■

Render Settings window on page 376

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Render Settings: mental ray tabs on page 404

mental ray for Maya rendering nodes For a description of the mental ray options in the Render Stats section of the object’s shape node, see: ■

Render Stats on page 511

mental ray for Maya Output window messages The following messages appear in the Maya’s Output window at start-up: ■ ■

mental ray for Maya 8identifies the version for mental ray for Maya. mental ray: version 3.3.0.655, 29 Jan 2004 Windows_NT_4.0_x86

identifies the version of mental ray standalone libraries that mental ray for Maya is based.

Work with mental ray for Maya approximation Create an approximation node 1 Select the geometry to which you want to assign an approximation node. For compatible geometry types, see Approximation nodes on page 182. 2 Click Window > Rendering Editors > mental ray > Approximation Editor. The Approximation Editor opens. For more information on the Approximation Editor see, mental ray Approximation Editor on page 363. 3 Click the Create button for the type of approximation node you want to create. For descriptions, see Approximation nodes on page 182. The approximation node is created and assigned to the selected geometry.

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Related topics ■

Approximation nodes on page 182

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Assign an approximation node on page 204

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Edit an approximation node on page 205

Assign an approximation node NOTE When you create an approximation node, it is automatically assigned to the selected geometry. Use this procedure to assign already created approximation nodes to newly selected geometry. 1 Select the geometry to which you want to assign an approximation node. For compatible geometry types, see Approximation nodes on page 182. 2 Click Window > Rendering Editors > mental ray > Approximation Editor. The Approximation Editor opens. For more information on the Approximation Editor see, mental ray Approximation Editor on page 363. 3 From the drop-down list for the type of approximation node, select the node you want to assign. For descriptions, see Approximation nodes on page 182. 4 Click Assign. The approximation node is assigned to the selected geometry.

Related topics ■

Approximation nodes on page 182

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Create an approximation node on page 203

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Edit an approximation node on page 205

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Edit an approximation node NOTE When you create an approximation node, it is automatically assigned to selected geometry. Use this procedure to assign already created approximation nodes to newly selected geometry. 1 Click Window > Rendering Editors > mental ray > Approximation Editor. The Approximation Editor opens. For more information on the Approximation Editor see, mental ray Approximation Editor on page 363. 2 From the drop-down list for the type of approximation node, select the node you want to edit. For descriptions, see Approximation nodes on page 182. 3 Click Edit. The approximation node’s Attribute Editor opens. 4 Edit the attributes

Related topics ■

Approximation nodes on page 182

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Create an approximation node on page 203

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Assign an approximation node on page 204

Unassign an approximation node NOTE When you create an approximation node, it is automatically assigned to the selected geometry. Use this procedure to unassign approximation nodes from any geometry. 1 Select the geometry from which you want to unassign the approximation node. 2 Click Window > Rendering Editors > mental ray > Approximation Editor. The Approximation Editor opens. For more information on the Approximation Editor see, mental ray Approximation Editor on page 363.

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3 From the drop-down list for the type of approximation node, select the node that you want to unassign from the selected geometry For descriptions, see Approximation nodes on page 182. 4 Click Unassign.

Related topics ■

Approximation nodes on page 182

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Create an approximation node on page 203

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Assign an approximation node on page 204

Delete an approximation node 1 Click Window > Rendering Editors > mental ray > Approximation Editor. The Approximation Editor opens. For more information on the Approximation Editor see, mental ray Approximation Editor on page 363. 2 From the drop-down list for the type of approximation node, select the node that you want to delete For descriptions, see Approximation nodes on page 182. 3 Click Delete. TIP If you want to disconnect an approximation node from a piece of geometry but keep the node in the scene, you can unassign the approximation node instead of deleting it. See Unassign an approximation node on page 205 for more information.

Related topics ■

Approximation nodes on page 182

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Create an approximation node on page 203

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Assign an approximation node on page 204

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Override approximation settings For complex scenes, many different approximation nodes with unique settings may be needed to ensure accurate and efficient renderings. When previewing such scenes, you can temporarily lower the tessellation quality to produce low-quality renderings more quickly with global (scene-wide) overrides. To override approximation settings 1 Click Window > Rendering Editors > Render Settings. The Render Settings window opens. For more information, see Render Settings window on page 376. In the mental ray tabs of the Render Settings window, the Options tab on page 444, Overrides section, Tessellation sub-section provides controls for specifying surface and displacement approximations to use for rendering. When specified, these settings override all approximation assignments in the scene. Selecting None will cause mental ray for Maya to once more respect the approximation assignments in the scene.

Obtain quads for subdivision surfaces For more information about mental ray for Maya geometry types, see mental ray for Maya geometry types on page 184. To get quads everywhere in a rejected subdivision surface 1 From the Surfaces menu set, select Subdiv Surfaces > Collapse Hierarchy >

.

2 Set Number of levels to 1. 3 Click Apply.

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Troubleshoot partial creases rendering as full creases Partial creases of subdivision surfaces are not supported in this version of mental ray for Maya. They will be rendered as full creases.

Control Fine approximation triangles Setting Fine approximation cache limit Fine displacement critically depends on the specification of a cache size limit, because otherwise the fine tessellation results would not flow through the cache but accumulate until memory runs out. mental ray has a default cache limit of 512 MB. A good choice is half the amount of physical RAM, or 500-800 MB on 32-bit machines, whichever is smaller. If the number is too large, the operating system may run out of virtual address space; if it is too small, mental ray will perform too many cache flush operations.

Control Fine approximation triangles Choose one of the following techniques to control fine displacement. These help you avoid the risk of accidentally creating billions of triangles until memory runs out, without juggling a large number of displacement-mapping parameters. When you use Fine approximation, you must choose one of these techniques: view length Specifies that all triangles should be subdivided until they are smaller than edge pixel diagonals. The edge value is typically around 0.5, or 0.25 or even 0.1 for very high quality. This technique is recommended for all fine approximations. length Specifies that the triangle edge length should stay under edge units in the object's object space. The edge parameter needs more careful tuning than in the view-dependent case, and very high values defeat the purpose of fine approximation.

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parametric Tessellates a free-form surface such that all microtriangles have the same size. This results in very regular meshes but is harder to optimize, and may use significantly more memory. This lets you define triangle size as a fraction of the surface size, instead of in object or screenspace mode.

Tweak Approximation node settings For each approximation setting, there are various settings, including tesselation method and style, that determine how the renderer tessellates objects at render time. You can manually change these settings or choose from a list of presets to simplify the process.

Presets Parametric Grid Parametric approximation subdivides the surface into u x v triangle pairs and tessellates each patch independently. If the surface is a curve, it ignores the v attribute. Use Parametric approximation for surface approximations and curves, and for trace-only or shadow-only geometry. Do not use for displacement. Regular Grid It is similar to the Parametric Grid approximation method, except that the tessellation density is the same throughout the entire surface or curve. Angle Tolerance The Angle approximation method subdivides the surface until every angle between normals of adjacent tiles is less than the number of degrees specified. Use in conjunction with the Angle on page 213 attribute. Pixel Length The Pixel approximation method takes into account both Length on page 211 and Distance. This method subdivides until no tile has an edge length that exceeds the specified Length. It also subdivides until the distance between the tessellation and the actual curve is less than the specified Distance. Use in conjunction with Any Satisfied. If Any Satisfied is selected, then only one of these conditions need to be satisfied. Otherwise, both conditions need to be satisfied. This method of approximation is view dependent and is not recommended for use with instances because the same tessellation is applied to all instances of the same object. This may result in a really high or really low tessellation for both a near and a far object, neither of which is ideal. It is also not recommended for camera flythroughs and for objects that are offscreen but

Control Fine approximation triangles | 209

still appear in reflections or shadows. For instances and camera flythroughs, use the Angle Tolerance approximation method.

Approximation method Parametric approximation Subdivides each patch of the surface into equal-sized pieces in the U direction and V direction. Regular parametric Curves are subdivided into equal pieces by the parametric approximation and into subdiv equal pieces by the regular parametric approximation. For displacement mapped polygons and displacement mapped surfaces with a displace statement regular parametric has the same meaning as parametric in the approximation. For displacement mapped polygons the u_subdiv constant specifies that each edge in the triangulation of the original polygon is subdivided for the displacement 2u_subdivtimes. If a displace approximation is given for a displacement mapped surface, the initial tessellation of the underlying geometric surface is subdivided in the same way as for polygons. For example, a value of 2 leads to a fourfold subdivision of each edge. Non-integer values for the subdivision constant are admissible. Nothing is done if the expression above is smaller than 2 (if u_subdiv < 1). The v_subdiv constant is ignored for the parametric approximation of displacement maps. Length/distance/angle (LDA) approximation Specifies curvature-dependent approximation according to the criteria specified by the Length on page 211, Distance on page 212, and Angle on page 213 attributes. Spatial approximation A special case of an LDA approximation that specifies only the length attribute and optionally the view attribute. Curvature A special case of LDA approximation, equivalent to the distance attribute, the angle attribute, and optionally the view attribute statement.

Approximation Style Tree, Grid, and Delaunay approximation algorithms are available for surface approximation only; they have no effect on curve approximations. Parametric approximation on page 210always uses the Grid algorithm; all other Approximation methods can use any style but Tree is the default. Grid Tessellates on a regular grid of isolines in parameter space. Tree Tessellates in a hierarchy of successive refinements that produces fewer triangles for the same quality criteria.

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Delaunay Creates a successive refinement that maximizes triangle equiangularity. Delaunay triangulation creates more regular triangles but takes longer to compute. U Subdivisions, V Subdivisions These values are used by the Parametric approximation on page 210and subdivides each patch of the surface into equal-sized pieces in the U direction and V direction. Regular parametric approximation methods specify how many times each patch (for Parametric) or surface (for Regular Parametric) should be subdivided in the U and V directions. Min, Max When using the Length/distance/angle (LDA) approximation on page 210adaptive approximation method, these attributes can be used to control the minimum and maximum number of times that triangles in the tessellation are subdivided. The Max Subdivisions parameter is especially useful for preventing runaway situations where the approximation method wants to add many triangles to an area where they will not greatly improve the quality of the tessellation. You can obtain good results with a Max Subdivisions value as low as 3. Generally, each subdivision level can increase the triangle count by a factor of 4, so raising the Max Subdivisions from 3 to 4 can produce 4 times as many triangles. Raising it to 5 can produce 16 times as many triangles, raising it to 6 can produce 64 times as many triangles, and so on. Max triangles This setting only applies to the Delaunay on page 211 approximation type. It determines the maximum number of triangles that the final tessellation may contain. Grading Applies only to Delaunay on page 211 approximation style. Varies the density of triangles around the border of the surface, allowing for a smooth transition between a fine curve approximation and coarser surface approximation. It prevents a large number of tiny triangles at the trimming or hole curve to abruptly join very large triangles in the interior of the surface. The angle constant specifies a lower bound related to the degree of the minimum angle of a triangle. Values from 0.0 to 30.0 can be specified. Small values up to 20.0 are recommended. The default is 0.0. High grading values require you to specify a maximum number of triangles (see Max triangles on page 211) to prevent too many triangles or endless mesh refinement. Length Subdivides the surface or curve so that no edge length of the tessellation exceeds the edge parameter. Edge is given as a distance in the space the object is defined in, or as a fraction of a pixel diagonal in raster space if the view keyword is present. Small values such as 1.0 are recommended.

Control Fine approximation triangles | 211

For Tree on page 210 and Grid approximation, the Min, Max on page 211 values (if specified), specify the minimum and maximum number of recursion levels of the adaptive subdivision. Min enforces a minimal triangulation fineness with no tests. Edges are further subdivided until they satisfy the given criterion or the max subdivision level is reached. The defaults are 0 and 5, respectively; 5 is a very high number. Good results often occur with a maximum of 3 subdivisions. For Delaunay on page 211 approximation, Min, Max on page 211 specifies the maximum number of triangles of the surface tessellation. This number is exceeded only if required by trimming, hole, and special curves because every curve vertex must become part of the tessellation regardless of the specified maximum. For displacement mapped polygons and displacement mapped surfaces, length limits the size of the edges of the displaced triangles and ensures that at least all features of this size are resolved. Subdivision stops as soon as an edge satisfies the criterion or when the maximum subdivision level is reached. Distance Specifies the maximum distance between the tessellation and the actual curve or surface. The value of dist is a distance in the space the object is defined in, or a fraction of a pixel diagonal in raster space if the view statement is present. As a starting point, a small distance such as 0.1 is recommended. For Tree on page 210and Grid approximation the min and max parameters, if present, specify the minimum and maximum number of recursion levels of the adaptive subdivision. For Delaunay on page 211approximation, the number max following the keyword max specifies the maximum number of triangles of the surface tessellation. For displacement mapped polygons and displacement mapped surfaces with a displace approximation statement the distance criterion cannot be used in the same way because the displaced surface is not known analytically. Instead, the displacements of the vertices of a triangle in the tessellation are compared. The criterion is fulfilled only if they differ by less than the given threshold. Subdivision is finest in areas where the displacement changes. For example, if a black-and-white picture is used for the displacement map the triangulation will be finest along the borders between black and white areas but the resolution will be lower away from them in the uniformly colored areas. In such a case one could choose a moderately dense parametric surface approximation that samples the displacement map at sufficient density to catch small features, and use the curvature-dependent displace approximation to resolve the curvature introduced by the displacement map. Even if the base surface is triangulated without adding interior points, as if its a trim curve defined a polygon in parameter space, it is still possible to guarantee a certain

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resolution by increasing the min subdivision level. Only the consecutive subdivisions are then performed adaptively. Angle The angle statement specifies the maximum angle in degrees between normals of adjacent tiles of a displaced polygon or the tessellation of a surface or its displacement or between tangents of adjacent segments of the curve approximation. Large angles such as 45.0 are recommended. For tree and grid approximation the min and max parameters, if present, specify the minimum and maximum number of recursion levels of the adaptive subdivision. For Delaunay approximation, the number max following the keyword max specifies the maximum number of triangles of the surface tessellation.

View dependent Controls whether the edge argument of the length and spatial statements and the dist argument of the distance and curvature statements are in the space the object is defined in or in raster space. Turn this on to express the Length and Distance attribute values in pixels instead of object-space units (the default). The advantage of using view-dependent values is that objects that are close to the camera receive many triangles, while objects that are far away (or not visible at all) are approximated much more coarsely. Length If the View Dependent attribute is turned on, this value is specified in pixels, otherwise it is specified in object-space units. The Length criterion is especially useful in conjunction with view dependency. For example, a view-dependent value of Length = 0.5 means subdivide until all triangles are no bigger than half a pixel in the resulting image. If the Length attribute is set to 0.0, this criterion is ignored by the tessellator. Distance If the View Dependent flag is turned on, this distance is expressed in pixels, otherwise it is expressed in object-space units. The lower the value, the more closely the tessellated surface will match the exact NURBS surface. Small values such as 0.1 work well (with view dependency disabled). If the Distance attribute is set to 0.0, this criterion is ignored by the tessellator. Spatial The Spatial approximation method is the same as the Length criteria from the Length/Distance/Angle method. Using this method, the mesh will be subdivided until all triangles are less than a certain size, determined by the Length attribute. This value is expressed in either pixels or object-space units, as determined by the View Dependent flag. This method is the only one available when using the Fine approximation type. Sharp Controls normal-vector calculations. If set to 0.0, mental ray for Maya uses the interpolated normal, as specified by the base surface, modified by

Control Fine approximation triangles | 213

displacement if available. If set to 1.0, mental ray for Maya uses the geometric normal to achieve a sharp faceted look.

Render time smoothing of polygon meshes Smooth polygon meshes at render time To smooth polygon meshes at render time, use the following workflow. This is a very efficient method of smoothing polygon meshes as it reduces the amount of data calculations during interactive manipulation. Major advantages for this feature include the following: ■

During translation, mental ray for Maya only translates the mesh hull, and the actual smoothing occurs at render time.

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This workflow delays smoothing until required because mental ray only tesselates and smoothes the mesh when a ray, for example, a camera ray, reflection ray, or shadow ray, hits the object.

The drawback of this feature, however, is that all Maya creasing will render differently with this technique, since the creasing appears different in the viewport as compared to its mental ray render. 1 Open the Approximation Editor (Window > Rendering Editors > mental ray > Approximation Editor). 2 Click the Create button beside the Subdivision approx. (Poly, Subdiv) attribute to create and assign a subdivision approximation to your polygon. 3 Render the scene in mental ray. NOTE You can also smooth polygon meshes by selecting Mesh > Smooth. This method creates denser geometry in the viewport and can increase the number of data calculations for interactive manipulation.

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Rendering a smooth polygon mesh Render a smooth polygon mesh using Smooth Mesh Preview

You can set up a smooth preview in the 3D viewport and then render it. 1 In the Render Settings window, under Render Using, select mental ray. 2 Select the polyShape node for your mesh. 3 In the Attribute Editor, expand the Smooth Mesh section and select Smooth Mesh Preview. 4 Select the level of smoothing for your mesh by tweaking the division level. A higher value produces more smoothing. If you want to use the same division level for the 3D viewport preview as for your render, select the Use Preview Level for Rendering option. Otherwise, uncheck the Use Preview Level for Rendering option and use the Render Division Levels slider or text field to enter the desired division level for your render.

Rendering a smooth polygon mesh | 215

NOTE To obtain smooth render effects, you must ensure that the Export Triangulated Polygons option in the Options tab on page 444, under the Translation section and Performance sub-section, is enabled.

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Contour rendering Adding a contour to your scene To add a (default) contour to your scene 1 In the Attribute Editor of the shading group node for your material shader, select Enable Contour Rendering under the Contours section. 2 In the Render Settings: mental ray tabs on page 404, Features tab on page 406 expand the Contours on page 410 section and select Enable Contour Rendering. 3 Select how you want your contours to behave with geometry by checking the applicable options under Draw By Property Difference on page 410 under the Contours on page 410 section. 4 Tweak the contour attributes to achieve the look that you desire. To add a contour shader to your scene 1 In the Attribute Editor of the shading group node for your material shader, map your mental ray contour shader, such as contour_shader_depthfade, to the Contour Shader attribute under the Custom Shaders section. 2 Tweak the contour shader attributes to achieve the look that you desire. 3 In the Render Settings: mental ray tabs on page 404, Features tab on page 406, expand the Contours on page 410section. Under the Custom Shaders section, map your custom contrast shader, for example, contour_contrast_function_levels, to the Contrast Shader attribute. Map your custom store shader, for example, contour_store_function to the Store Shader attribute. 4 Tweak the contour shader attributes to achieve the look that you desire. For a description of the node attributes for the mental ray contour shaders, see the mental ray Shaders Guide in the Maya Help.

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Work with multi-render passes Introduction to multi-render passes: a simple workflow example

In this scene there is a render layer, named KitchenSink, which includes a sink and a spotlight. The sink has a Phong shader applied to it and the spotlight’s Use Ray Trace Shadows attribute is enabled. Use the following simple workflow to obtain a diffuse, reflection, shadow and specular pass for this layer. NOTE The multi-render pass feature is supported for the mental ray renderer. The rendering API allows other 3rd party renderers and custom renderers to support it moving forward.

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Create render passes for the render layer 1 With the KitchenSink layer selected, open the Render Settings window and select mental ray as your renderer.

2 Select the Passes tab and click the New Pass button to create a new render pass. The Create Render Passes window appears. 3 Select the following render passes. You can multi-select items: Diffuse Without Shadows, Reflection, Shadow, and Specular Without Shadows. Click the Create and Close button. Four render passes named diffuseNoShadow, reflection, shadow, specularNoShadow are created and appear under the Scene Passes section NOTE By default, a beauty pass is also created for the each layer once the selected passes have been created. 4 Use the arrow buttons to move the passes to the Associated Passes section. This makes the passes available to the current layer.

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5 Render the scene. By default, if you render from the scene view, your rendered images are saved to the subdirectory \\ under the images\tmp directory of your project file. Maya also creates a MasterBeauty folder where it saves the default beauty pass for the scene. The image file name .iff is used for each rendered image. If you batch render, the rendered images are saved directly to the images directory. NOTE If you render using the Render View window, you can also preview your render pass output by selecting File > Load Render Pass.

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Beyond this example In addition to creating render passes for the entire render layer, you can also create render passes for a subset of the objects and lights in your render layer. You can do this by creating a render pass contribution map. See Creating render pass contribution maps on page 224 for more information. You can also customize the subfolders and filenames to which the rendered images are stored. See Creating subfolders and filenames for rendered images on page 227 for more information. If you have many render passes in your scene, you can group them into render pass sets, for example, an Illumination pass set that includes all passes involving lights, such as diffuse, and ambient. See Using render pass sets in your scene on page 231 for more information.

Related topics ■

Passes tab on page 404

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Render pass nodes on page 501

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Multi-render passes on page 187

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Sample workflow for multi-render passes

This sample workflow illustrates how to do the following: ■

Use the Render Layer Editor to create render pass contribution maps. Although this step is optional, render pass contribution maps give you finer control over light and objects and their passes relationship. For example, you can use pass contribution maps to easily create a diffuse pass for a specific object that is illuminated by a specific light.

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Create render passes for each render pass contribution map.

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Render the scene and create the subfolders and filenames for the rendered images.

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Group render passes into render pass sets and render the set.

NOTE For a list of available passes, and a list of shaders that is currently supported by the multi-render pass workflow, see Multi-render passes on page 187. NOTE The multi-render pass feature is supported for the mental ray renderer. The rendering API allows other 3rd party renderers and custom renderers to support it moving forward.

Rendering with render pass contribution maps Creating render pass contribution maps In this scene (KitchenSinkModel.ma), there is a render layer, named KitchenSink, with two objects, a sink and a bowl, and a light. A Phong shader is applied to the sink and a Lambert shader is applied to the bowl.

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1 Select the bowl and light in your scene view. In the Render Layer Editor, right-click the layer and select Pass Contribution Maps > Create Pass Contribution Map and Add Selected. passContributionMap1 is created. Double-click it and change its name to Bowl. 2 Select the sink and light in your scene view. In the Render Layer Editor, right-click the layer and select Pass Contribution Maps > Create Pass Contribution Map and Add Selected. Change its name to Sink.

Related topics ■

Render Layer Editor on page 367

Create render passes for each render pass contribution map 1 Open the Render Settings window and select mental ray as your renderer.

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2 First, create the render passes for your sink render pass contribution map. Select the Passes tab and click the New Pass button to create new render passes. The Create Render Passes window appears. 3 Multi-select the following render passes: Diffuse Without Shadows, Reflection, Specular, and Shadow. In the Pass Prefix field, enter Sink. Click the Create and Close button. The following passes are created: SinkDiffuseNoShadow, SinkReflection, SinkShadow, SinkSpecular. The passes appear under the Scene Passes section.

4 Create the render pass for the bowl render pass contribution map. Select button to create a new render the Passes tab and click the New Pass pass. The Create Render Passes window appears. Select the Diffuse render pass and enter Bowl in the Pass Prefix field, then click Create and Close. The BowlDiffuse pass appears under the Scene Passes section. 5 Before you can apply these render passes to each pass contribution map, you must first make these passes available to the current layer. Use the arrow buttons to move the passes to the Associated Passes section. 6 Using the Associated Pass Contribution Map drop-down list, select the pass contribution map that you want to select render passes for, for example, Sink. 7 Use the arrow buttons to move the SinkDiffuseNoShadow, SinkReflection, SinkShadow, and SinkSpecular passes to the Passes Used by Contribution Map section.

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8 Repeat this procedure to add the BowlDiffuse pass to the Passes Used by Contribution Map section for the Bowl pass contribution map. 9 Render the scene. Your rendered images are saved to the images directory of your project file as described below.

Related topics ■

Passes tab on page 404

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Render pass nodes on page 501

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Multi-render passes on page 187

Creating subfolders and filenames for rendered images By default, your rendered images are saved to the subdirectory \\ under the images\tmp directory of your project file. The image file name .iff is used for each rendered image.

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NOTE All image output from render passes are saved to the images\tmp directory of your project file unless you run a batch render. Running a batch render saves your render passes output to the images directory. NOTE If you render using the Render View window, you can also preview your render pass output by selecting File > Load Render Pass. You may want to customize the subdirectories and filenames for the rendered images instead. For example, you may not want a folder to be created for each layer and camera. Use the tokens available from the File name prefix attribute under the File Output section in the Render Settings: Common tab on page 377. and combine them with separators such as _ or -. For example, you may want to use the __ tags to create the filenames for your images. In this sample workflow, the following images are produced: ■

KitchenSinkModel_KitchenSink_BowlDiffuse.iff

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KitchenSinkModel_KitchenSink_SinkDiffuseNoShadow.iff

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KitchenSinkModel_KitchenSink_SinkReflection.iff

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KitchenSinkModel_KitchenSink_SinkShadow.iff

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KitchenSinkModel_KitchenSink_SinkSpecular.iff

■

KitchenSinkModel_KitchenSink_MasterBeauty.iff (This is the default

beauty pass for the layer.) NOTE If you use the default File Output directory, Maya creates a MasterBeauty folder to which it saves the default beauty pass for the layer. If you customize the File Output directory, a MasterBeauty.iff image is created for the beauty pass.

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Sample workflow for multi-render passes | 229

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Using render pass sets in your scene If your scene includes many render passes, you may want to group them into render pass sets. You can create render pass sets using the Create Render Passes window at the same time as when you are creating your render passes.

Sample workflow for multi-render passes | 231

1 In the Create Render Passes window, select the passes that you want to include in your pass set. 2 Enable the Create Pass Set option. Enter a Pass Set Name, for example, Illumination. Click Create Passes. 3 The Illumination pass now appears in the Scene Passes section. 4 To render this pass set for the current layer, use the arrow buttons to move the render pass set to the Associated Passes section.

5 Select the Illumination pass set and click the Pass Set Relationship Editor button. The Relationship Editor window appears and you can see that the Illumination pass is automatically associated with all the passes that you created simultaneously.

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6 Render the scene. By default, the rendered images are saved to \\ under the images\tmp directory of your project file.

Related topics ■

Relationship Editor

Exporting the multi-render passes for compositing in Toxik

After setting up your render layers and creating your render passes in Maya, you may want to export your elements to be composited in Toxik. 1 Select Render > Export Pre-Compositing. The Export Pre-Compositing window appears. 2 The Export Pre-compositing editor is divided into three tabs: Cameras, Render Layers and Render Passes. Select the appropriate tab depending on the elements that you want to export. 3 Use the

icon to expand the render layer, render camera, or render pass

hierarchy and select the elements that you want to export. A icon indicates that all elements are being exported and A icon indicates that only partial elements are being exported.

Exporting the multi-render passes for compositing in Toxik | 233

4 Enter a scene anchor name in the Pre-Compositing Scene Anchor field. Toxik uses the scene anchor name to identify the elements that should be included in the composite. If a composite with the specified anchor name does not exist, Toxik builds a new one and adds to it all the elements with the same scene anchor. Otherwise, if the composite already exists, it is updated and all elements with the same scene anchor are included in the composite. NOTE Unlike the scene name, which can change, for example, from version one to version two, the scene anchor does not change. It uniquely connects a Maya scene to a scene composition in a Toxik project. All elements that belong to the same composite, for example, cameras, render passes, render layers, and so forth, should have the same scene anchor. A scene anchor is only required if you plan to updated your scene compositions in Toxik. 5 Click the Export All or Export Selection button to export your render layers, passes and cameras to Toxik. The Export PRECOMP file window opens that allows you to enter a filename for your exported file. NOTE Before exporting to Toxik, ensure that all your scene elements are named correctly. Avoid renaming elements (for example, a camera name or a render pass name) halfway through your workflow. Toxik does not recognize the renaming of scene elements, since renamed elements are flagged as new elements to be inserted in the compositions. Therefore, if your composition contains old and new elements, you are responsible for cleaning up your composition after an update. For example, if you export for the first time with camera1 and then change your camera name to camera2 and export again, Toxik does not update the camera in the composite from camera1 to camera2. Instead, your composite now contains two cameras: camera 1 and camera 2.

Using templates with the pre-compositing workflow You can also create a template that instructs Toxik on how to update the composite. A template is a Toxik precomp file with nodes that contain anchor information. For example, if you have 15 passes in your scene, but only 2 of the passes are blended together in the template, then only these 2 passes are blended together in your composite. Specify a template for each layer using the Render Settings window, Passes tab. When Toxik sees the template, it duplicates it, and then looks for the elements with specific anchors (render layer/camera/render pass anchors).

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Create and use a template with the pre-compositing workflow 1 Create a template by exporting your scene elements to Toxik. A composite is created. 2 Add compositing operators, such as blend and comps or math compositing nodes, to the composite and save it as a .txcomposition template file. 3 Use a different template for each render layer. Select a render layer and open the Render Settings window, Passes tab. Enter the template in the Pre-Compositing template for attribute. Repeat for each render layer. 4 Select Render > Export Pre-Compositing to export the scene elements to Toxik.

File formats supported by Toxik Refer to the following table for list of file formats that Toxik supports, as well as their supported bit depths. Format

File Extnesion

Supported bit depths for imported files

Bitmap

.bmp

8

Cineon

10

DPX

.dpx

8, 10, 16

HDR

.hdr

32

IFF

.iff

8, 16, 32

JPEG/JFIF

.jpg, .jpeg

8

OpenEXR

16 bit float, 32

Photoshop

.psd

8, 16

PICT

.pict

8, 16

Exporting the multi-render passes for compositing in Toxik | 235

Format

File Extnesion

Supported bit depths for imported files

PNG

.png

8, 16

QuickTime

.mov

SGI

.sgi

8, 16

RGB

.rgb

8, 16

Targa

.tga

8, 16

TIFF

.tif, .tiff

8, 16, 32

Softimage

.pic

8

RLA

.RLA

8, 16

NOTE Bit depths 8, 10, and 16 are integer unless otherwise indicated. Bit depth 32 is float.

Set scene options Open the Render Settings window The settings you use to produce your final rendered image or sequence of images depend on a number of factors, including: ■

the renderer you use

■

the medium to which you are outputting

■

whether you are rendering in layers and passes for compositing

■

whether you are preview rendering or producing the final rendered image(s)

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NOTE The changes you make in the Render Settings window affect the entire scene. Often, it makes sense to adjust settings on a per-object setting.

Render settings for the Hardware renderer, the mental ray for Maya renderer, the Maya software renderer, the Maya Vector renderer are available from the Render Settings window. The Common tab of the Render Settings window contains the attributes common to most of the renderers, which decreases the number of parameters you need to modify when switching between renderers. Settings specific to the chosen renderer are available in a another tab. For detailed descriptions of the settings in the Render Settings window, see Render Settings window on page 376. To open the Render Settings window 1 Do one of the following: ■

Click Window > Rendering Editors > Render Settings.

■

Click the Display Render Settings Window button on the main toolbar or in Render View.

■

Select Options > Render Settings in Render View.

You can edit settings in the Common tab and the renderer-specific tab. For more information, see Render Settings window on page 376.

Modify a mask channel For Maya software and mental ray for Maya. To increase or decrease the mask value for an object 1 In the Matte Opacity section of an object’s material Attribute Editor, set Matte Opacity Mode to Opacity Gain and adjust the Matte Opacity value. During rendering, Maya first generates the mask channel, then multiplies the mask values for the object by the Matte Opacity value. For example, if Matte Opacity is 1, the mask values for the object remains unchanged; if Matte Opacity is 0.5, the mask values for the object are half their original values.

Modify a mask channel | 237

To set the mask value for an object to a constant value 1 In the Matte Opacity section of an object’s material Attribute Editor, set Matte Opacity Mode to Solid Matte and adjust the Matte Opacity value. If the object is transparent, any objects behind it appear in the mask channel. During rendering, Maya first generates the mask channel, then sets the mask values for the object to the Matte Opacity value. For example, if Matte Opacity is 1, the mask values for the object are 1; if Matte Opacity is 0.5, the mask values for the object are 0.5. To set the mask value for an object to zero 1 In the Matte Opacity section of an object’s materials Attribute Editor, set Matte Opacity Mode to Black Hole. During rendering, Maya first generates the mask channel, then sets the mask values for the object to 0. If the object is transparent, any objects behind it will not appear in the mask channel.

Adjust anti-aliasing in mental ray for Maya NOTE You may not need to adjust quality settings for an entire scene. Adjusting settings on a per-object basis is often more efficient and has less of an impact on rendering speed. For more information on aliasing artifacts and strategies on how to fix them, see Adjust scene anti-aliasing parameters (Maya software) on page 157.

mental ray anti-aliasing specifics Manually adjust the following: ■

Quality Presets

■

Sampling Mode

■

Custom Sampling ■

Min Sample Level = 0

■

Max Sample Level = 2

■

Filter = Triangle or Gauss

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Set motion blur in mental ray for Maya When you render an animation, motion blur gives the effect of movement by blurring objects in the scene. For more information on motion blur, see Focus and blur on page 15.

mental ray motion blur specifics Supports only 3D motion blur. To set motion blur, in the Quality Presets section of the Render Settings window on page 376 set Quality to an option that includes Motion Blur, then work with the settings in the Motion Blur section of the Render Settings window on page 376.

Perform command line rendering Rendering from the command line Your scene file determines whether you render a single frame or an animation. You can render from a shell or a command line. Before rendering, you may

Set motion blur in mental ray for Maya | 239

want to close all applications, including Maya, to maximize the amount of memory available for rendering. When you render from a command line, you can set flags that override some of the Render Settings, saving time during test renders. For more information, see Render from the command line in the Rendering Utilities guide. To get quick renderer-specific information 1 Type: Render -r rendername -help

where rendername is the name of the renderer. Use the following options: ■

mr = mental ray

■

sw = software renderer

■

hw = hardware renderer

■

vr = vector renderer

■

file = the file within which the renderer is specified NOTE If you get help on a file (-r file -help), only the flags common to all renderers, not a specific renderer, are shown. If you want renderer-specific information, you must specify the renderer.

All flags have a short description. Each flag corresponds to the appropriate section of the Render Settings window. See the Render Settings documentation for more detailed information on each option. To obtain a complete list of command line Render options, from a shell or command line 1 Type: Render -help

To render a scene with a specific renderer from a shell or command line 1 Type: Render -r scene

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TIP You may need to provide the -proj flag when issuing the render command to specify where the scene file is located. For example, type: Render scene -proj

To render a scene with the renderer specified in the file from a shell or command line 1 Whichever renderer is specified in the file is used to render the scene. Type: Render -r file

To batch render using user-defined region rendering 1 Use the -reg flag. For example: render -r mr -reg 0 100 0 100 scene.ma

where -reg 0 100 0 100 indicates the region to be rendered in pixels (left, right, bottom, top). The above command renders the lower left 100 x100 pixel region of the scene.

Export .mi files Export a .mi file and render with mental ray There are two ways to export a .mi file for rendering with mental ray. The first method is to use the File > Export All option. The second method is to use the mi exporter from the command line. ■

To export a .mi file and render with mental ray using File > Export All

■

To export a .mi file using the command line

To export a .mi file and render with mental ray using File > Export All 1 Select File > Export All. 2 Choose a file name and path and click Options.

Export .mi files | 241

The Export All Options window appears. 3 Select mentalRay as the file type. There are File Type Specific Options in the Export All Options window you can use to control file naming schemes and other details. 4 Click Export All. TIP You can use the Esc key to cancel a mental ray for Maya export operation. This functionality cancels the export operation, but Maya remains running.

To export a .mi file using the command line 1 Use the -r mi flag. See Command Line Flags for more information. For example: Render -r mi -rd "C:/images" -im "cmdTest" -of "tif" -s 10 -e 15 -b 1 -binary 0 -perframe 0 -exportPathNames "1111111111" file "C:/temp/test.mi" mayascene.ma

The command above exports frames 10 to 15 (-s, -e, and -b flags), and exports one .mi file for the entire animation (-perframe flag). The exported .mi file is in ASCII format (-binary flag), with the path and filename C:/temp/test.mi. The .mi file uses the absolute path for its full name (-exportPathNames flag). When the test.mi file is rendered with a Standalone renderer, the output image file is in tif format (-of flag) with the filename cmdTest (-im flag), and stored in the c:/images directory (-rd flag).

Related Topics: ■

Exporting MI files using the command line

Managing your scenes using render proxies Using render proxies in your scene

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Use render proxies to manage large scenes with complex geometry. If your scene includes a complex piece of geometry, you can first export the object as a mental ray assembly file, and then replace it in your scene with a placeholder object that references this file. When you render, the exported object is loaded into memory and rendered with the rest of your scene. The overall translation is instantaneous, since there are virtually no geometries being passed to mental ray. Translation time and memory usage are therefore drastically reduced, allowing mental ray for Maya to render large scenes. NOTE The use of render proxies can cut down translation time and memory usage in several ways. First of all, complex geometry is never loaded into Maya. It is only loaded into mental ray if necessary. If the proxy is occluded or behind another object or behind the camera, then it is not loaded. Also, the texture file associated with the render proxy is not loaded unless the proxy is. Furthermore, mental ray for Maya can also unload the entire render proxy during rendering in order to reduce memory consumption. Create a render proxy as follows: . See File 1 Export your geometry by selecting File > Export Selection > > Export All, Export Selection (mental ray) on page 309 for more information. NOTE When you export your render proxy using the default settings, you also export its shading network. Therefore, shading that you apply to the placeholder does not take effect. To change this behavior, customize your export options by selecting File > Export Selection >

.

2 Under the General Options section, File type attribute, select mentalRay. 3 Under the File Type Specific Options section, Export selection output: attribute, select Render Proxy (Assembly). NOTE When creating your render proxy, do not compress your .mi header file because Maya needs to read the bounding box data from the .mi file. 4 Click Export Selection, and save your object as a .mi file. NOTE Place your proxy object at the origin before exporting it to a .mi file. For example, if your proxy is at x=10 during the export, the placeholder item will also be moved by 10.

Using render proxies in your scene | 243

Rendering your scene using a render proxy 1 Create a simple base geometry as a placeholder for your more complex geometry.

2 In the base geometry's shape node, expand the mental ray section. In the Render Proxy section, select your render proxy .mi file. Your base geometry is now resized so that it fits the original render proxy object.

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3 In the base geometry's transform node, expand the mental ray section. In the Render proxy section, ensure that Renderable is enabled to render the proxy instead of your base geometry. 4 Render your scene. Your base geometry is replaced by your render proxy in the render view.

Using render proxies in your scene | 245

NOTE Assign the proxy file before animating the placeholder. The Freeze Transformations operation fails if the transformation has incoming connections. Therefore, you should animate the placeholder after assigning to it the proxy file.

Material assignments for render proxy You can apply a shader to your render proxy in one of two ways. You can retain the render proxy’s original shader assignment, or you can assign a material to the base geometry, and then apply that to the render proxy as well. To retain the render proxy’s original shader assignment, when exporting your geometry, select File > Export Selection > , and then ensure that Export materials and Export material assignments under File Type Specific Options are selected. Otherwise, if you de-select Export materials and Export material assignments under File Type Specific Options, your render proxy will be exported without its material and material assignment. When you assign a material to your base

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geometry, this material assignment is also applied to your render proxy in the final render.

Increase render speed Increase overall rendering speed in mental ray for Maya To make a scene render faster, do any of the following: ■

Diagnose the scene to find ways to render the scene faster using Render > Run Render Diagnostics. You can use this tool to monitor how well you optimize the scene and to search for limitations and potential problems that may occur. For more information on render diagnostics, see Run diagnostics on page 166 and mental ray for Maya diagnostics on page 197.

■

Perform scene optimizations:

■

■

Click File > Optimize Scene Size > to turn options on or off to optimize everything in the scene and to remove unused or non-valid elements. See File > Optimize Scene Size in the Basics guide for more information about this window.

■

For Maya software rendering, use Block ordered texture set up. See Cache texture tiles using BOT (block ordered texture) on page 163.

■

If the scene contains objects with construction history and you no longer need it, delete it. See the Construction history in the Basics guide for details.

Avoid memory swapping by: ■

Closing all applications before rendering to maximize the amount of memory available for rendering (including Maya if rendering from a shell or command line).

■

Setting the TEMP or TMPDIR variable as the location for temporary render cache files: -TMPDIR (Linux) or - TEMP (Windows and Mac OS X) to make plenty of room for temporary rendered files. Make sure that the value of those variables points to a local, fast hard drive, not a network drive.

Increase render speed | 247

■

For Maya software and mental ray for Maya, Test Resolution (Render > Test Resolution) lets you select a reduced resolution to test render the scene. For more information on test rendering strategies, see Visualize interactively with IPR on page 123.

■

For Maya software, if the scene contains several identical surfaces (for example, multiple spheres), use Optimize Instances in the Render Settings: Maya Software tab on page 388 to improve rendering performance.

■

Turn off motion blur if you don’t need it (the Vector renderer has no motion blur). For the Maya software renderer, use 2D motion blur instead of 3D motion blur when possible. See 2D Motion Blur global attributes and 3D Motion Blur in the Render Settings window on page 376 for details.

Use average BSP (mental ray for Maya) settings When mental ray for Maya raytraces, it calculates the effects using an average of the depth and the average of the leaf size settings of the BSP. To speed up subsequent renderings, you can render instead with the average settings (instead of your initial settings). Find the averages in Maya's Output Window after you render the scene the first time (with Verbosity Level set to Progress Messages or above in Render > Render Current Frame > and Render > Batch Render > the settings in the Memory and Performance section.

Example averages found in the Output Window ■

RCI 0.2 info : main bsp tree statistics:

■

RCI 0.2 info : max depth : 40

■

RCI 0.2 info : max leaf size : 114

■

RCI 0.2 info : average depth : 22

■

RCI 0.2 info : average leaf size : 7

■

RCI 0.2 info : leafnodes : 8185

■

RCI 0.2 info : bsp size (Kb) : 393

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), then change

Increase surface rendering speed in mental ray for Maya Do any of the following: ■

Use single-sided instead of double-sided surfaces (which is the default) on the object’s Attribute Editor. The biggest speed gain is for the Maya hardware renderer.

■

Tessellating large surfaces requires a lot of memory, so use several small surfaces instead of one large surface when you can. The renderer is more efficient with smaller surfaces.

■

For Maya software rendering and Maya hardware rendering, use bump mapping instead of displacement mapping.

■

For Maya software rendering, make bump maps flatter. To do this, reduce the value of the Alpha Gain attribute, which smooths the bump map and reduces the number of samples of adaptive shading. This technique only works when Edge Anti-aliasing is set to Highest Quality. The texture bump looks flatter when the Alpha Gain is lower.

■

For Maya software rendering, turn on Use Displacement Bounding Box when using displacement maps.

■

For Maya software rendering, use layered textures when possible, instead of a Layered Shader. (See Layered shaders and 2D and 3D textures in the Shading guide for details.)

■

For Maya software rendering and mental ray for Maya, if you are raytracing the scene, set the Reflection Limit and Refraction Limit to the lowest values that produce acceptable results.

■

For Maya software rendering, in the Render Settings: Maya Software tab on page 388 on Linux, Use File Cache avoids re-tessellation of the same surface during rendering. Turn on Use File Cache to store geometric data in a separate file in a location that you specify (the default location is /usr/tmp, but you can set a new location by typing setenv TMPDIR xxx, where xxx is the name of the directory where this file is output).

Increase surface rendering speed in mental ray for Maya | 249

Increase shadow rendering speed in mental ray for Maya To make shadows render faster, do any of the following: ■

For Maya software and mental ray for Maya, use depth map shadows instead of raytraced shadows.

■

For surfaces that do not need to cast shadows, turn off Casts Shadows.

To make depth map shadows render faster, do any of the following: ■

Set the Resolution to the lowest value that produces acceptable results. (For shadow casting spot lights, first reduce the Cone Angle to the lowest value that produces acceptable results.)

■

Turn on Use Auto Focus (or set the Focus to the lowest value that produces acceptable results. See Focus, Width Focus) and set the Resolution to the lowest value that produces acceptable results.

■

For Maya software rendering, set the light’s Filter Size to the lowest value that produces acceptable results. A Filter Size value of 2 or more is usually sufficient. For mental ray for Maya, adjust the Resolution, Samples, and Softness settings under the light’s Shadow Map section.

■

For Maya software rendering, Set Fog Shadow Samples to the lowest value that produces acceptable results.

■

For Maya software rendering, set Disk Based Dmaps to Reuse Existing Dmap(s).

■

For Maya software rendering, if a point light does not have to produce shadows in the light’s positive or negative X, Y, or Z directions, turn off the appropriate Depth Map Shadow Attributes : Use X+ Map, Use X- Map, Use Y+ Map, Use Y- Map, Use Z+ Map, or Use Z- Map.

■

For Maya software rendering, if the scene contains NURBS surfaces, in the Memory and Performance Options section of the Render Settings: Maya Software tab on page 388, make sure Reuse Tessellations is on (the default setting).

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To make raytraced shadows render faster (for Maya software rendering and Maya hardware rendering), do any of the following: ■

If the Light Radius (or the Light Angle for directional lights) is greater than 0, set Shadow Rays to the lowest value that produces acceptable results. See Shadow Radius, Light Radius, Light Angle for details.

■

Set Ray Depth Limit to the lowest value that produces acceptable results.

Diagnose scene problems mental ray for Maya error handling and diagnostics Error messages mental ray for Maya checks for errors in a scene and recognizes various operating system errors. If an error is detected, a message appears in Maya's script editor. If a critical error is found, mental ray for Maya aborts the current process. The message verbosity can be changed by selecting a different Verbosity Level option in the "Render > Render Current Frame >

" and "Render > Batch

Render > ". When using the interactive renderer mental ray for Maya prints messages to the Output Window (Windows) or the Console (Linux). When batch rendering with mental ray for Maya, a log file is created. If severe errors are encountered during database access of mental ray, the final rendering doesn’t get started.

Diagnostics You can use diagnostics to help you diagnose issues with samples and photon maps. You can specify Diagnose Grid and Grid Size, as well as Diagnose Photon Density or Irradiance. See Run diagnostics on page 166.

Diagnose scene problems | 251

Network rendering Network render with mental ray for Maya Before you begin, you must have networked workstations. See your system administrator if workstations are not networked. You can set up masters using mental ray standalone or mental ray for Maya, using different method to specify which hosts to use as network render slaves. NOTE If you have multiple versions of mental ray standalone installed (not recommended), each must have their own TCP port number in the services file to avoid conflict. For example: mi_ray3_0maya4_0 7051/tcp mi_ray3_1maya4_5 7052 and 7053/tcp mi_ray3_2maya5_0 7054/tcp

Related topics ■

mental ray network rendering: Satellite and standalone on page 199

■

Submit a job to render over the network on page 262

Set up mental ray network rendering To set up mental ray network rendering 1 Ensure that you have networked workstations. The slave machines must be accessible on the network where the master machine is installed. 2 Ensure that any firewall software is not interfering with the operation of your network rendering software. 3 Ensure that all necessary services (for mental ray standalone or Satellite) are running. 4 mental ray service should be installed and running.

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5 Set up your master machine by creating a rayhost file. Ensure that it is located in the right directory. You can set up your master machine using mental ray standalone or mental ray for Maya (Satellite). For more information, see: ■

Set up a master machine with mental ray for Maya or mental ray for Maya Satellite on page 254.

■

Set up a master machine with mental ray standalone (method 1) on page 257.

■

Set up a master machine with mental ray standalone (method 2) on page 258.

6 Install mental ray standalone or mental ray for Maya Satellite on each slave machine. All slave machines require mental ray for Maya Satellite or mental ray standalone. If you have multiple versions of mental ray standalone installed (not recommended), each must have their own TCP port number in the services file to avoid conflict. For more information, see Network render with mental ray for Maya on page 252. 7 Set up your slave machine(s) by following these instructions: Slave machine setup on page 259. 8 To verify which hosts file is being read, and which render slaves are being used, use the mentalrayrender command with a verbosity setting of 4 or higher. For more information, see Set up a master machine with mental ray standalone (method 1) on page 257 9 To submit a render job, follow these instructions: Submit a job to render over the network on page 262. NOTE You must uninstall mental ray satellite for previous versions before installing new mental ray satellite. The mental ray satellite for Maya packages have the same name. Therefore, you must manually uninstall previous versions of mental ray satellite before installing the current version of mental ray satellite. On Mac OS X, you need to use the mental ray satellite uninstaller in the mental ray satellite folder to properly uninstall this product. If you delete the mental ray satellite folder, port and machine associations may not be updated properly once you install the latest version of mental ray satellite.

Set up mental ray network rendering | 253

Set up a master machine with mental ray for Maya or mental ray for Maya Satellite First, create a file called maya.rayhosts.

maya.rayhosts file format The maya.rayhosts file must contain a listing of each slave machine’s name. These slave machines must be accessible on the network where mental ray for Maya (the master machine) is installed. For mental ray for Maya masters going to mental ray standalone slaves, you do not need to specify the port if you are using the default port (7009). For mental ray for Maya Satellite masters, you must add the port number by typing “:” after the hostname in the maya.rayhosts file. The port number set on mental ray for Maya Satellite slave machines is 7109. For example: pc-host1:7109 pc-host2:7109

If you are using a non-default port, you can specify it here as well: lnx-host2:7555

You can use # to comment hosts out so they won’t be used; for example: # pc-slave4:7109

You can use IP addresses as well as machine names. NOTE The port on which the slave listens is specified by the services file on the slave machine. For more information, see Slave machine setup on page 259. It is 7009 for mental ray standalone and 7109 for mental ray for Maya Satellite (as of Autodesk Maya 2009). The port on which the master issues requests is set in the maya.rayhosts file or defaults to 7009 (the mental ray standalone port). The port number on the slave and the port number on the master must match for rendering to take place.

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maya.rayhosts file location Put the maya.rayhosts file in one of the following directories. (They are searched in order and the first maya.rayhosts file that is found is used.) ■

Maya 2009 prefs folder: Windows ■

(Windows XP) \Documents and Settings\\My Documents\maya\ 2009\en_US\prefs

■

(Windows XP 64-bit) \Documents and Settings\\My Documents\maya\ 2009x64\en_US\prefs

■

(Windows Vista) \Users\\Documents\maya\2009\en_US\prefs

■

(Windows Vista 64-bit) \Users\\Documents\maya\2009-x64\en_US\prefs

Mac OS X ■

/Users//Library/Preferences/Autodesk/maya/en_US/2009/prefs

Linux (64-bit) ■

■

■

■

~/maya/2009-x64/en_US/prefs

Maya Application folder: ■

(Windows) %USERPROFILE%\My Documents\maya

■

(Linux) $HOME/maya

■

(Mac OS X) /Applications/Autodesk/maya/2009

User's home directory: ■

(Windows) %USERPROFILE% or %HOMEDRIVE%\%HOMEPATH% (usually c:\)

■

(Linux and Mac OS X) $HOME

Directory of Maya 2009 installation folder. ■

(Linux) /usr/autodesk/maya2009/

Set up a master machine with mental ray for Maya or mental ray for Maya Satellite | 255

■

(Windows) C:\Program Files\Autodesk\maya2009\

■

(Mac OS X) /Applications/Autodesk/maya2009/

Related topics ■

mental ray network rendering: Satellite and standalone on page 199

■

Verify which hosts file is being read on page 256

■

Submit a job to render over the network on page 262

Verify which hosts file is being read To verify which hosts file is being read 1 Set the verbosity level for messages from the translation process by using the MEL command as outlined in Export Verbosity on page 290. During a render, messages similar to the following are output to the Script Editor: // Info: (mental ray) : loading startup file C:/Program Files/Autodesk/Maya 2009/mentalray/maya.rayrc // mental ray for Maya: using rayhosts file C:/Documents and Settings/user1/My Documents/maya//maya.rayhosts

Additionally, error messages from mental ray for Maya are printed to the Maya Output Window.

Related topics ■

mental ray network rendering: Satellite and standalone on page 199

■

Submit a job to render over the network on page 262

Change the set of slaves used for mental ray for Maya renders To change the set of slaves being used for mental ray for Maya renders 1 Close Maya, modify the appropriate maya.rayhosts file, and restart Maya.

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Related topics ■

mental ray network rendering: Satellite and standalone on page 199

■

Submit a job to render over the network on page 262

Set up a master machine with mental ray standalone (method 1) To set up a master machine with mental ray standalone - method 1 1 Create the .rayhosts file. Each line of the file should specify the name of a machine to be used as a network render slave. 2 Place the file in one of the following locations: ■

Place a file called .rayhosts in the home directory of the current machine. On Linux and Mac OS X the home directory is specified by the $HOME environment variable. On Windows machines, it is specified by %HOMEDRIVE%\%HOMEPATH% (on most machines, this is C:\).

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Place a file called .rayhosts in the current directory, for example, from where the render will be invoked. A .rayhosts file in the current directory overrides one in the machine's home directory.

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NOTE To verify which hosts file (if any) is being read, and what network render slaves are being contacted, use the mentalrayrender command with a verbosity setting of 4 or higher. For example, runningD:\> mentalrayrender -v 4 test.mi could produce the output: MAIN .0 info : mental ray, version 3.4 MAIN .0 info : [...] MAIN .0 info : MAIN 0.0 info : version 3.4, 4 Dec 2004 MAIN 0.0 info : compiled on: Windows NT 4.0, x86 MSG 0.0 info : reading hosts file C:\\.rayhosts MSG 0.0 info : connecting host foobar1:7054 JOB 0.0 info : started thread 0 on foobar1 now known as host 1 MSG 0.0 info : connecting host foobar2:7054 JOB 0.0 info : started threads 0,1 on foobar2 now known as host 2 .....

This indicates that the hosts file C:\.rayhosts was read, and that it specified network render slaves foobar1 and foobar2 for use in this rendering. The started thread 0, 1... messages indicate that the slaves were successfully contacted.

Related topics ■

mental ray network rendering: Satellite and standalone on page 199

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Submit a job to render over the network on page 262

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Set up a master machine with mental ray standalone (method 2) on page 258

Set up a master machine with mental ray standalone (method 2) To set up a master machine with mental ray standalone - method 2 1 Use the -hosts option with the mentalrayrender command, for example: mentalrayrender -hosts machine1 machine2 sceneFile.mi

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This uses machine1 and machine2 as render slaves. This overrides any .rayhosts files on the master machine.

Related topics ■

mental ray network rendering: Satellite and standalone on page 199

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Set up a master machine with mental ray standalone (method 1) on page 257

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Submit a job to render over the network on page 262

Slave machine setup All slave machines require mental ray for Maya Satellite or mental ray standalone. When you install mental ray standalone, the installation automatically sets up your machine as a server to receive network render requests. If you are encountering problems with network rendering follow the steps below. To set up a slave on Windows (mental ray standalone) 1 Ensure there is a rayrc file in the mental ray installation directory (C:\Program Files\Autodesk\mentalray). This file is automatically created during a default installation. 2 Ensure that the mental ray service is installed and running. To verify this, go to the Services window from the Administrative Tools and check to see if the Ray Server service exists and is started. If the Ray Server service exists but is not started, go to step 5. 3 If the Ray Server service does not exist, edit the services file located at: ■

(Windows XP) C:\WINNT\system32\drivers\etc\services

4 Make sure the following lines exist: mi-ray 7009/tcp mi-spm 7050/tcp

7009 represents the port number used for rendering requests and 7050 represents the port number used for licensing connections to SPM. Make sure the port number used for rendering requests is the same on the master machine and all slave machines (here, 7009).

Slave machine setup | 259

5 Open a command prompt window and type the following: ray /install ray.exe should automatically be in your path and is located in the bin directory of the mental ray installation.

6 Double-click the Ray Server service in the Services Window (Administrative Tools in the Control Panel) to start it. When the service successfully starts, the machine is ready to receive network render requests. When you install mental ray for Maya Satellite on a slave machine, the installation automatically sets up your machine as a server to receive network render requests. If you are encountering problems with network rendering follow the steps below. To set up a slave on Windows (mental ray for Maya Satellite) 1 Ensure there is a rayrc file in the mental ray installation directory (C:\Program Files\Autodesk\mentalraysatellite\). This file is automatically created during a default installation. 2 Ensure that the mental ray service is installed and running. To verify this, go to the Services window from the Administrative Tools and check to see if the RaySat Server service exists and is started. If the RaySat Server service exists but is not started, go to step 5. 3 If the RaySat Server service does not exist, edit the services file located at: ■

(Windows XP) C:\WINNT\system32\drivers\etc\services

4 Make sure the following line exists: mi-raysat2009 7109/tcp

7109 represents the port number. Make sure the port number is the same on the master machine and all slave machines. 5 Open a command prompt window and type the following: raysat2009 /install raysat2009.exe should automatically be in your path and is located in the bin directory of the mental ray installation.

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6 Double-click the RaySat Server service in the Services Window (Administrative Tools in the Control Panel) to start it or type raysat2009 /start. When the service successfully starts, the machine is ready to receive network render requests. The mental ray standalone installer does not set up your machine as a slave automatically. You need to follow the steps below with administrative privileges on all Linux machines. To set up a slave on Linux (mental ray standalone) 1 In a shell type: /usr/autodesk/mi361/bin/netsetup -s

You are prompted for the name of the SPM license server. It defaults to the local host. 2 Type in the SPM license server name if it is other than the default local host and then press Enter. The machine is now ready to receive network render requests. The mental ray standalone installer does not set up your machine as a slave automatically. You need to follow the steps below with administrative privileges on all Mac OS X machines. To set up a slave on Mac OS X (mental ray standalone) 1 Add the install location of mental ray to your path: /Applications/Autodesk/mentalray3.6.1/bin

2 Create a new environment variable called SPM_HOST to identify your license server machine. The machine is now ready to receive network render requests.

Related topics ■

mental ray network rendering: Satellite and standalone on page 199

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Submit a job to render over the network on page 262

Slave machine setup | 261

Submit a job to render over the network Once you are set up, the process of rendering over the network is fully automatic so that every render you invoke from a client machine is automatically distributed over the network. To network render a Maya scene within Maya on a master machine 1 Ensure that the maya.rayhosts file has the name of all mental ray network rendering slaves you wish to use (see Set up a master machine with mental ray standalone (method 1) on page 257). 2 Start Maya, open a scene and select Render > Render Using > mental ray. 3 Select Render > Render Current Frame. 4 To verify that the slave machines are being used, select Render > Render Current Frame > (or Render > Batch Render> ) and select Progress Messages from the Verbosity Level drop-down list. You should see messages in the console window (or in the mental ray log file for batch render) telling you which slave machines were connected and which machine is being used to render particular tiles. To network render a Maya scene with Maya from the command line on a master machine 1 Ensure that the maya.rayhosts file has the name of all mental ray network rendering slaves you wish to use (see Set up a master machine with mental ray standalone (method 1) on page 257). 2 From a command prompt window, change to the directory where your Maya scene resides. 3 Type the following: Render -r mr sceneName.mb

To network render with a mental images (.mi) scene with mental ray standalone on a master machine 1 This works with mental ray standalone only; this operation is not supported for mental ray for Maya Satellite. Ensure that the maya.rayhosts file has the name of all mental ray network rendering slaves you wish to use (see Set up a master machine with mental ray standalone (method 1) on page 257).

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2 From a command prompt window, change to the directory where your .mi file resides. 3 Type the following: mentalrayrender myFile.mi

4 To get progress messages to show how the slave machines are being used, type the following command: mentalrayrender -verbose 5 myFile.mi

Related topics ■

mental ray network rendering: Satellite and standalone on page 199

Dynamic Attributes for mental ray for Maya Dynamic Attributes The following dynamic attributes are designed to work in conjunction with custom shaders. Some of these attributes are not always visible by default in the Maya user interface. However, once you have created the attribute, you can view and edit the value in the Extra Attributes section in the Attribute Editor.

User Data Custom information can be incorporated into elements of a scene such as lights, cameras, objects, and instances. Use the dynamic miData attribute to connect a mental ray User Data node to the element so that this custom information can be accessed by mental ray shaders. NOTE In order to use the following workflow, you must have a mental ray shader with a data attribute. 1 Create a mental ray User Data node using the command: createNode -n "miUserData" mentalrayUserData;

The mentalrayUserData node should contain custom user data that matches the format required by your mental ray shader.

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2 Connect miUserData.message to shader.data The mentalrayUserData node consists of two attributes: binaryData and asciiData. asciiData is the preferred method. The asciiData attributes should be filled with custom user data and connected to the mental ray shader using the mentalrayuserData.message plug. NOTE The mentalrayUserData node is only translated if connected to a mental ray shader. 3 Create the miData attribute as follows: addAttr -ln "miData" -at message pSphereShape1;

4 Connect the miData attribute to the userdata node as follows: connectAttr -f miUserData.message pSphereShape1.miData;

TIP Add a magic number to the user data, preferably as the first value in the block. This allows your shaders to easily identify the user data.

Export shadow shader Use this attribute to have transparent shadows even when photons are used. The attribute functions locally and overrides the shadowEffectsWithPhotons attribute (the Direct Illumination Shadow Effects setting in Caustics and Global Illumination > Photon Tracing section of the Render Settings), on a per-material basis, so that shadow shaders are exported even when photons are turned on. Create this attribute as follows: addAttr -ln miExportShadowShader -at bool phong1SG;

Disable animation detection mental ray automatically detects animation of scene objects and related shading nodes when translating subsequent frames. The Optimize Animation Detection option (in the Render Settings window, mental ray tabs, in the Options tab on page 444, Translation section, Performance sub-section) even performs a pre-scan of the Maya dependency graph to find animated nodes much faster and to mark the individual nodes accordingly for accelerated translation of the whole animation. There are ways to hint to mental ray about animated nodes manually, in cases where the default performance might still not be optimal or the standard detection algorithm does not catch all animations.

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Individual instances or whole DAG subtrees can be excluded from being considered for animation by adding a new dynamic attribute 'miAnimated' (boolean)and setting it to off. Once found on a transform node, the DAG traversal prunes the remaining subtree from animation detection (not the node itself). The Optimize Animation Detection option needs to be turned off to activate the manual overrides. Create this attribute as an override on the shape node as follows: addAttr -ln miAnimated -at bool group1;

Disable DG cycle detection Use this attribute to turn off the detection of cycles in the dependency graph when very complex shading networks are used, to improve performance. Cycles in shading networks may cause mental ray for Maya to become unstable in some cases. Set this attribute to false to disable the DG cycle detection. Create this attribute as follows: addAttr -at bool -ln "nodeCycleCheck" mentalrayGlobals

Force on-demand translation of geometry Use the Export Objects On Demand option to control the processing of objects in your scene. This option is particularly effective in scenes that have objects beyond the view of the camera. In this case, mental ray does not process the objects beyond the camera view, therefore reducing processing time. Create this attribute as an override on the shape node as follows: addAttr -ln "miPlaceholder" -at bool pSphereShape1

Disable custom node automatic light linking NOTE This attribute is not required if light linking mode is set to 4. It is only needed for shaders that do not support mental ray light linking. See Native mental ray light linking in the Shading guide for more information. Use this attribute to turn off automatic light linking on a per-node basis (set the attribute to false). This is useful when the same material is used by several objects that have different light linking. In this case, disable light linking with this attribute, then manually connect the light nodes to the shader’s light attributes. Create this attribute as follows:

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addAttr -ln "miLightLink" -at bool mib_illum_lambert1

Label To enable export of mental ray labels, this dynamic attribute is recognized on the transform node of geometry. mental ray does not perform any checks on these labels, but just exports them. There is no label framebuffer support at this time. Create this attribute as follows: addAttr -ln "miLabel" -at long nurbsSphere1

Cutout opacity Add the miCutAwayOpacity (float) to the material’s shading engine. This attribute is useful for 2D stand-ins or card objects where a complex 2D shape is cut out of a plane by means of transparency mapping. miCutAwayOpacity is an opacity threshold. All surface points that are less

opaque than specified are considered non-existent. For example, a value of 0.05 removes all surface points with a transparency of 99.5% or more. Create this attribute as follows: addAttr -longName "miCutAwayOpacity" -attributeType "float" shad ingGroup1;

Custom motion vectors mental ray for Maya supports the creation of zero-length motion vectors. Custom displacement shaders can manipulate the motion vectors to generate motion blurred displacement. Only geometric shape nodes that are marked with the attribute miCustomMotion (boolean) set to true are considered for custom motion. The global option Export Custom Vectors on page 452 can be used to control this feature. It is enabled by default. If disabled, no custom motion vectors are generated for any object. This functionality also requires that Motion Blur on page 394 has been enabled in mental ray render settings. Create this attribute as follows: addAttr -ln "miCustomMotion" -at bool myShapeNode;

where myShapeNode is a shape node.

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Force displacement animation To specify that an object contains animated displacement, add the miDisplaceAnimation (boolean) dynamic attribute to the object shape node. This is a hint to the translation engine and avoids potentially expensive traversal of the DG to detect animated displacement. Create this attribute as follows: addAttr -ln "miDisplaceAnimation" -at bool myShapeNode;

Force triangle export of polygon meshes This option processes all polygon meshes as tessellated triangles, based on Maya’s tessellation. This allows for more efficient use of memory so that large scenes with large polygon meshes render with less memory usage. For more information, see Export Triangulated Polygons on page 449. In addition, there is support on each shape node for the dynamic attribute miTriangles (boolean), which overrides the global setting on a per-shape basis. Therefore, two common scenarios are supported: ■

disable triangles globally but enable it for specific shapes,

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enable triangles globally but disable it for specific shapes.

Create this attribute as follows: addAttr -ln "miTriangles" -at bool myMeshNode;

Force lights emitted photons In the Attribute Editor for each Maya light, the mental ray section of the attributes specifies the number of photons that are used for caustics and global illumination. This is, by default, the number of photons to be stored. For correct physical simulations, the number of photons to be emitted is much more appropriate. To support this, mental ray recognizes two attributes on directional, point, and spot lights: 'causticPhotonsEmit' (integer) 'globIllPhotonsEmit' (integer).

If they are created they will be translated and exported in addition to the photon stored number.

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Create these attributes as follows: addAttr -ln "causticPhotonsEmit" -at "short" myLightShape; addAttr -ln "globIllPhotonsEmit" -at "short” myLightShape;

Photon only lights The mental ray light property photons only can be controlled on Maya light nodes using the dynamic attribute 'miPhotonsOnly' (boolean)

If photon emission is enabled on the light node then this attribute is recognized and translated to mental ray. To optimize photon tracing performance, you can mark light sources as only being considered for photon emission and disable their direct light contribution in mental ray. Create this attribute as an override on the light shape node as follows: addAttr -ln "miPhotonsOnly" -at bool spotLightShape1

Translate polygon meshes as subdivision base mesh primitives You can smooth polygon meshes by assigning them a subdivision surface approximation (that is, a mentalraySubdivApprox node) either through the Approximation Editor, or, manually. Beginning Maya 2008, the subdivision approximation node produces ccmesh primitives instead of subdivision base mesh primitives. To revert to the old behavior, add the dynamic attribute 'miExportCCMesh' (boolean)

to mentalraySubdivApprox nodes. If turned off, mental ray for Maya translates smoothed polygon meshes to subdivision base mesh primitives. These are often slower and require more memory than ccmesh primitives. Create this attribute as an override on the shape node as follows: addAttr -ln "miExportCCMesh" -at bool mentalraySubdivApprox1

Custom flags The Maya transform node does not expose all extended instance flags for mental ray, but they can be controlled via dynamic attributes: 'miReflection' (integer) 'miRefraction' (integer) 'miTransparency' (integer)

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The value is an index into predefined flags (bit sets): ■

0 - cast off, receive off

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1 - cast on, receive on

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2 - no bit set, inherit

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3 - cast on, receive off

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4 - cast off, receive on

Create the attributes above by following these examples: addAttr -ln "miReflection" -at "enum" -enumName "Cast Off Receive Off:Cast On Receive On:Inherit:Cast On Receive Off:Cast Off Re ceive On" myTransformNode addAttr -ln "miRefraction" -at "enum" -enumName "Cast Off Receive Off:Cast On Receive On:Inherit:Cast On Receive Off:Cast Off Re ceive On" myTransformNode addAttr -ln "miTransparency" -at "enum" -enumName "Cast Off Receive Off:Cast On Receive On:Inherit:Cast On Receive Off:Cast Off Re ceive On" myTransformNode

If any of the reflection and refraction attributes is present, then the standard trace flag is not respected any more. 'miFinalGather' (integer)

This attribute follows the scheme of the existing caustic and globillum standard flags, and supports the following values: ■

0 - hide on

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1 - cast off, receive off

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2 - cast on, receive off

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3 - cast off, receive on

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4 - cast on, receive on

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5 - not bit set, inherit

Create this attribute as follows: addAttr -ln "miFinalGather" -at "enum" -enumName "Hide On:Cast Off Receive Off:Cast On Receive Off:Cast Off Receive On:Cast On Re ceive On:Inherit" myTransformNode

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Custom element To enable file export of a replacement element instead of the currently instanced Maya shape, use the dynamic attributes: 'miExportElement' (boolean) 'miElement' (string)

If the boolean option is enabled, the replacement element is exported as the object name, without further checks. Create these attributes as follows: addAttr -ln "miExportElement" -at bool myTransformNode addAttr -ln "miElement" -dt "string" myTransformNode

Custom phenomenon for translation To enable translation of a different material than the currently assigned Maya shading engine, use the dynamic attributes: 'miExportMaterial' (boolean) 'miMaterial' (message)

If the boolean option is enabled, the replacement material, typically a connection to a Maya shading engine or a custom node, is translated as the instance material. If the connected node is a custom node of type material, it is translated as a full replacement of the regular material description in mental ray. Create these attributes as follows: addAttr -ln "miExportMaterial" -at bool myTransformNode addAttr -ln "miMaterial" -at message myTransformNode

Rasterizer shading samples override The global option for rasterizer shading quality (mental ray: shading samples) can be overridden on a per-object/per-instance basis. The per-object override can be accessed via the Shading Quality attribute in the Attribute Editor of the object’s shape node, in the mental ray section. For per-instance override, the dynamic attribute 'miShadingSamples' (float)

is recognized on the Maya shape and transform nodes and translated to mental ray if its value is not negative. Create this attribute as follows:

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addAttr -ln "miShadingSamples" -at "float" myTransformNode

Depth-of-field samples override The depth-of-field effect in Maya (controlled on the camera) uses a mental ray custom lens shader which performs true 3D depth-of-field rendering, shooting multiple rays per pixel to get a smooth result. The number of these extra lens samples is pre-defined to 4 but can be adjusted in two ways. You can add the dynamic attribute 'dofLensSamples' (integer)

to the mental ray globals node, which defines a new default for all depth-of-field effects on all cameras in the scene. Create this attribute as follows: addAttr -ln "dofLensSamples" -at "short" mentalrayGlobals

A per camera override is supported as well by adding the dynamic attribute 'miLensSamples' (integer)

to the Maya camera shape node. Create this attribute as follows: addAttr -ln "miLensSamples" -at "short" perspShape

When the objects get out of focus, it is often necessary to raise the number of samples.

Disk swapping To enable disk swapping, add the dynamic attributes 'miDiskSwapLimit' (integer) 'miDiskSwapDir' (string)

to the mental ray globals node. Once enabled, disk swapping cannot be disabled later on for the same mental ray session (Maya session). Create these attributes as follows: addAttr -ln "miDiskSwapLimit" -at "short" mentalrayGlobals addAttr -ln "miDiskSwapDir" -dt "string" mentalrayGlobals

For a description of the options see mental ray documentation.

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Memory mode mental ray watches memory consumption during integrated rendering (preview and batch), and may react to low memory conditions to circumvent mental ray fatal memory errors which normally crash Maya. By default, mental ray is aborted when any memory request exceeds the currently set memory limit plus a 'zone' of 20% (matching the recommendation of setting the memory limit to 80% of installed physical memory). This functionality can be adjusted by adding the following dynamic attribute to the mental ray globals node: 'memoryMode' (enum: none, report, inquiry, abort, release)

The mode values are as follows: ■

'none' (0) to disable the memory handling altogether

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'report' (1)

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'inquiry' (2) to print a warning message in the script editor

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'abort' (3) to force an interrupt of mental ray rendering

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'release' (4) to call a MEL procedure to release memory in Maya

The existing attribute memoryZone on the mental ray globals node can be used to control the zone (in percent of memory limit) that determines when memory handling should come into action and proceed according to mode. Create this attribute as follows: addAttr -ln "memoryMode" -at "enum" -enumName "None:Report:In quiry:Abort:Release" mentalrayGlobals

String options support (for Maya 2008 and below) Many features can be controlled by string options, which minimizes parse errors. Use the dynamic attribute: 'miDefaultOptions.stringOptions' (compound, multi):

It has 3 children name, type, and value, all of type string, which provide the required information for the mental ray option. More children are possible but will be silently ignored by mental ray. Set an attribute as follows:

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setAttr -type "string" miDefaultOptions.stringOptions[0].name "motion factor"; setAttr -type "string" miDefaultOptions.stringOptions[0].type "scalar"; setAttr -type "string" miDefaultOptions.stringOptions[0].value "1.0";

More attributes can be set by using a different array index. Reusing an existing index overwrites the corresponding option. The following keywords are recognized in the type and value fields: mray type

type string

value string

miBoolean

"bool[ean]"

'on' 'off' 'true' 'false' '0' '1'

miInteger

"int[eger]"

integer value

miScalar

"scal[ar]"

floating-point value

miScalar

"float"

floating-point value

miVector

"vec[tor]"

3 floats

miColor

"col[or]"

4 floats

miString

"[string]"

string

This attribute is created automatically for Maya 2008. For pre-Maya 2008 scenes, create the attribute as follows: addAttr tions; addAttr tions; addAttr tions; addAttr tions;

-at compound -nc 3 -ln "stringOptions" -multi miDefaultOp -dt "string" -p "stringOptions" -ln "name" miDefaultOp -dt "string" -p "stringOptions" -ln "value" miDefaultOp -dt "string" -p "stringOptions" -ln "type" miDefaultOp

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TIP Beginning Maya 2009, you can set your string options through the miDefaultOptions Attribute Editor. See miDefaultOptions node on page 306 for more information.

To turn off network baking mental ray provides an attribute that allows you to control the use of satellites for integrated baking of textures. By default, mental ray sets this attribute to true: setAttr miDefaultOptions.lightMapsNetwork false

However, mental ray may disable this option for the actual bake run when it detects unsupported cases such as when Bake to one map is enabled in any active bake set.

Ambient occlusion To calculate ambient occlusion more accurately when transparency is a factor, turn on the Occlusion Deep attribute. You can expose this attribute using the following dynamic attribute: addAttr -at "bool" -ln "occlusionDeep" textureBakeSet1

Hide objects from final gather rays Add the dynamic boolean attribute miFinalGatherHide to the shape node of your object so that it becomes invisible to final gather rays. This is different from disabling the Final Gather Cast and Final Gather Receive flags, which turn the object into a black hole as far as final gather is concerned. Set this attribute as follows: addAttr -ln "miFinalGatherHide" -at bool myShapeNode;

Elliptical filtering

You can obtain advanced features in elliptical filtering by setting the following dynamic attributes. For more information regarding these attributes, see the Auxiliary Functions section in the mental ray for Maya reference guide.

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Bilinear texture pixel interpolation When the elliptical area is smaller than a texture pixel, you can turn on bilinear texture pixel interpolation by setting miEllipticalBilinear to 1 (TRUE) to create a more blurry image. addAttr -longName "miEllipticalBilinear" -at bool -defaultValue 1 file1;

Maximum eccentricity Set the maximum eccentricity of the ellipse using the miEllipticalEccMax dynamic attribute. The value of this attribute must be equal to or greater than 1.0. The eccentricity of the ellipse is the major radius divided by the minor radius. A high eccentricity value results in long rendering times; therefore, if the eccentricity is higher than the specified maximum, the minor radius of the ellipse is increased accordingly. addAttr -longName "miEllipticalEccMax" -at "float" -defaultValue 4.0 -minValue 0.001 -maxValue 40.0 file1;

Distance between sampling points For every three sampling points in texture space, you can set the maximum distance between the two additional sampling points and the central sampling point. In other words, if the central sampling point is at (0, 0), then the other two points should be inside a disc with radius of DiscR from this central position. Set the DiscR value as follows: addAttr -longName "miEllipticalDiscR" -at "float" -defaultValue 0.3 -minValue 0.001 -maxValue 1.0 file1;

Setting the circle radius You can set the size of the projected screen--space circle using the miEllipticalCircleR attribute. You may get more blurring when you use larger values but you may increase aliasing with smaller values. Use a range of 0.4 to 1.0. addAttr -longName "miEllipticalCircleR" -at "float" -defaultValue 0.8 -minValue 0.001 -maxValue 1.0 file1;

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Troubleshoot mental ray for Maya rendering Use these suggestions to troubleshoot mental ray for Maya rendering, and to fine tune effects in your scenes. Specifically, see: ■

Troubleshoot general mental ray for Maya rendering issues on page 276

■

Troubleshoot render layers do not render correctly when exporting a .mi file on page 282

■

Troubleshoot Motion Blur on page 282

■

Troubleshoot Surfaces on page 283

■

Troubleshoot Network rendering with mental ray for Maya on page 284

Troubleshoot general mental ray for Maya rendering issues Geometry shaking from frame to frame when exported to .mi In some cases, files exported to .mi for rendering with mental ray standalone appear to have shaking geometry from frame to frame. In this case, there are three possible solutions.

Method 1 When exporting to a .mi file, export using the binary file format instead of ascii to prevent data loss due to conversion.

Method 2 The loss in precision is due to mental ray for Maya exporting only six digits of precision for float point positions, and 15 digits of precision for double point positions. For example, the float point value 1000.2249 is rounded to 1000.22 when exported. To increase the precision, you can use the Export Float Precision, and Export Double Precision dynamic attributes. Create these attributes by entering the following in the status line:

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addAttr -type short -ln “exportFloatPrecision” mentalrayGlobals addAttr -type short -ln “exportDoublePrecision” mentalrayGlobals

Set these attributes as follows: setAttr mentalrayGlobals.exportFloatPrecision setAttr mentalrayGlobals.exportFloatPrecision

where is the number of digits of precision you want to use.

Method 3 Avoid using large object offsets with very tiny shape deformations, which results in vertex positions such as 1000.000001. This exceeds the precision of floating point representation in general, and the .mi format does not have a double representation of vertex positions.In situations where the default precision is not sufficient to represent the scene in a .mi file, the Maya model should be reviewed to avoid extreme values: ■

global placement of scene elements should only use the instance transformation matrix, and

■

local features and deformations should use only the vertex/point data of the shape.

Some Maya modeling features such as skinning are known to bake global transformation into the final shape properties, which may lead to the described problems in extreme cases.

mental ray for Maya rendering errors If you experience mental ray for Maya rendering errors, and you save your Maya scene, you should not try to re-render your scene immediately. Instead, exit and restart Maya.

Error message try -memory error appears When there is not enough memory to render your scene, you may see an error message that is similar to "MEM 0.3: TRY -MEMORY 314".To troubleshoot, select Render > Render Current Frame > and increase the Memory Limit to be higher than or equal to that stated in the error message.In general, however, when an out of memory condition occurs, you should also review your scene for possible optimization.

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Some older derive from Maya settings no longer apply Because of the (as of Maya 5.0) unified render settings (see Open the Render Settings window on page 236), some of the mental ray for Maya derive from Maya settings no longer exist. You may need to modify some older files for which derive from Maya was set by setting the mental ray for Maya render settings. For known differences between mental ray for Maya and Maya, see mental ray for Maya renders look different than Maya renders on page 278.

Object still renders when primary visibility is turned off When an object is occluded by a transparent object, for example, an image plane, the object still renders even if its Primary Visibility flag (under the Render Stats section of the object’s Attribute Editor) is turned off. Turn off the Visible in Transparency flag instead (under the mental ray section of the object’s Attribute Editor). This behavior only occurs in mental ray for Maya. This is because, unlike the Maya renderer, mental ray for Maya distinguishes between Primary Visibility and Transparency. When Primary Visibility is turned off, mental ray still recognizes the geometry that is behind the transparent occluding object and includes it in the render. To exclude this geometry, disable the Visible in Transparency flag. NOTE This behavior also only occurs when the occluding object is Transparent. If you set up your scene with the Primary Visibility turned off for the occluding object, this behavior does not occur.

mental ray for Maya renders look different than Maya renders The following sections describe known differences between Maya and mental ray for Maya and provide hints on how to handle those cases.

Scanline Only Rendering Scanline only rendering is the default render mode in Maya. Since scanline rendering is limited in various aspects, it may show artifacts when used together with the following: motion blur, volume rendering, shadow tracing, and others. Raytracing should be turned on if render problems appear.

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Displacement mental ray uses an adaptive tesselation approach to better fit the details of the displacement map. The initial tesselation (for NURBS: after surface approximation) is further subdivided to fit secondary criteria, controlled by the displace approximation settings. By default, mental ray for Maya creates appropriate settings that lead to curvature dependent subdivision of the triangles, one form of feature-based displacement mapping. You can change these settings by creating or selecting a custom displace approximation node in the Approximation Editor. For more information on Approximation Nodes, see Approximation nodes on page 182).

Shadow Mapping If the mental ray shadow map attributes on Maya lights are disabled, mental ray for Maya derives most parameters for shadow maps from Maya's depthmap settings, although most control values are not comparable. This causes different results, especially when modifying the filter values to achieve soft shadows. For sharp shadows the Filter Size should be set to 0. Other controls, like Use Mid Dist and Use Auto Focus are not used to derive mental ray shadowmap values. For information about the way mental ray for Maya handles shadow mapping, see Shadow in Maya in the Lighting guide.

Bump mapping The bump mapping implementation in the mental ray shaders may handle the Filter settings in the bump nodes slightly differently compared to Maya. This filter usually produces view-dependent bump mapping details, but might not be appropriate in animations. As soon as the filter has been disabled by setting the Filter value to zero, the Filter Offset determines the bump map lookup, both in Maya and mental ray. This leads to comparable bump mapping render results that are not view-dependent.

Matte Opacity Transparent objects produce an appropriate alpha channel in the final image according to Maya’s Matte Opacity settings. However, some restrictions apply: ■

The mental ray colorclip modes and the premultiply setting affect the matte result. The default colorclip mode Raw ensures best compatibility with Maya, especially when using the BlackHole opacity mode, or when

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sliding the Matte Opacity value towards zero in OpacityGain and SolidMatte modes. ■

The mental ray colorclip modes other than Raw may change the color or alpha value before storing it in the framebuffer, which can be used to produce nice effects.

■

The BlackHole opacity mode may cause different results in the color channel when rendered with mental ray; reflections may still show up.

For more information on transparency, see Surface texture in the Shading guide.

Depth-of-Field This effect is supported with a mental ray lens shader, not as an output filter as in Maya. Therefore, it is dependent on the global sampling settings in mental ray. Raising the minimum or maximum sampling level improves quality and but slows down the rendering accordingly. On the other hand, as a true 3D effect, it won't show any artifacts with problematic scenes, where output filters are not able to produce correct depth-of-field blurring.

Render Layers When assigning a group to a render layer, mental ray for Maya assumes all the members of the group also belong to that layer and inherit its attributes. However, Maya allows members of the group to be assigned to different layers than the group parent.

Particle system translation and rendering Particle types for software rendering are supported on all platforms for rendering with mental ray. To render particles, a new mayabase shader library is required, which is also provided for all platforms. Particle data are also exported to .mi files. These files cannot be rendered on machines with different byte ordering (big end or little end) than the machine where Maya has been used (for example, mixing Linux and Windows). Particle translation and rendering is limited and may not be able to handle large particle counts. Light linking is not supported with particles. However, software particles and particle instancing should work together seamlessly.

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Tearing off mental ray for Maya Render menu may crash Maya If you tear off the Maya Render menu, then load the mental ray for Maya plug-in and tear off the mental ray for Maya Render menu, Maya may crash.

Workaround Close the menu before loading mental ray for Maya.

mental ray for Maya crashes or won’t load when a firewall is active Firewall software may block command ports. When you load mental ray for Maya, your firewall prompts you if you want "to allow the Maya application to access the internet: IP 127.0.0.1 port 1333." If you select no, Maya instantly exits without a warning or error message. If you select yes, mental ray for Maya starts up as expected.

Workaround If you are using any firewall software, you will need to give permission to Maya to communicate on port 1333 in order for mental ray for Maya to work correctly.

3D Paint issues with mental ray for Maya When painting a texture with 3D Paint, mental ray for Maya will not pick up new paint strokes automatically.

Workaround Save either the texture being painted or the entire scene before rendering with mental ray to ensure that all strokes are rendered correctly.

mental ray images folder By default, mental ray batch rendered images used to go to mentalRay/images folder of the project. As a result of the design changes in Maya 7 that made all renderers more consistent, any such images are now being saved to the images folder under the project.

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Rendering speed is slower than expected when submitting multiple renders on a muli-core machine When several renders are submitted on a multi-core machine, the amount of memory being used is much higher. On the other hand, a single render across multiple cores yields better rendering speed because memory can be shared.

Troubleshoot render layers do not render correctly when exporting a .mi file When exporting your scene as a .mi file, if your scene consists of more than one render layer, you must select the Output file per layer option in order to obtain renders in which your render layers do not affect each other. This restriction applies because mental ray interprets each single .mi file as a sequence of "incremental changes" in the scene. Therefore, completely independent render layers containing different sets of objects cannot be represented efficiently in a single .mi file.

Troubleshoot Motion Blur Incorrect motion blur with overexposed highlights Overexposed highlights and incorrect motion blur with mental ray for Maya motion blur may be caused by the framebuffer Data Type. In this case, change the framebuffer Data Type to a float framebuffer. For more information, see Framebuffer on page 429.

Missing Motion Blur When rendering with motion blur, sometimes parts of deforming geometry will fail to blur. This is because sometimes, during animation, Maya creates incompatible changes to vital mesh data (number and order of vertices, normals, uv indices, polygons). You need to ensure a consistent tessellation for mental ray.

Workaround Turn on the "keep tesselation" flag on the smooth node, and do not triangulate.

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Troubleshoot Surfaces Aliased surface edges or profile For more information regarding troubleshooting surfaces for Maya software, see Troubleshooting Surfaces (Maya software) on page 146. To fix aliased surface edges or profile (for Maya software and mental ray for Maya) 1 If you do not plan to composite the rendered image, turn on Premultiply in the Render options section of the Render Settings window on page 376.

Troubleshoot final gather causes flicker If you are rendering a scene with final gather and the lighting flickers, follow these steps: 1 Enable the Optimize for Animations option under the Final Gathering Tracing section, Final Gathering Tracing subsection in the Indirect Lighting tab on page 432 of the Render Settings: mental ray tabs on page 404. The Optimize for Animations option sets the final gather mode to multiframe. See Final Gathering Modes in the mental ray for Maya reference guide for more information. 2 Set the Render Mode to render final gather maps using this command: setAttr mentalrayGlobals.renderMode 3;

3 Set the scene to render a representative subset of frames or a coarse version of the animation. 4 Set Rebuild to Freeze under the Final Gathering Map section of the Indirect Lighting tab on page 432 of the Render Settings: mental ray tabs on page 404. 5 Set Render Mode to full render using this command:

Troubleshoot Surfaces | 283

setAttr mentalrayGlobals.renderMode 0;

6 Fully render the scene. NOTE While this workflow avoids flicker, some parts of the scene may still suffer in quality if an insufficient number of final gather points is found.

Troubleshoot Network rendering with mental ray for Maya The instructions below refer to mental ray for Maya 2009 and mental ray standalone 3.6.1. For information on previous versions, refer to the documentation for that version of Maya or mental ray.

Why can’t I install the rayserver service or edit the services file? Ensure you have administrator (or root) privileges on the machine.

I have everything correctly set up, but I still can't network render. Here are various possibilities to check.

Port number One possibility is that the network port number you are using is already being used by another service. Ensure that there is no other entry in the services file that is using port 7009 (mental ray standalone) or port 7109 (mental ray for Maya Satellite). If that port number is already taken, you need to pick a new available port number and use that same number for all master and slave machines that are to work together. You may need to change the port number. To do so on Linux and WIndows, edit the port services file located at: ■

(Linux) /etc/services

■

(Windows XP) C:\Windows\system32\drivers\etc\services

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To do so on Mac OS X: ■

(Mac OS X) Open NetInfo manager (/Applications/Utilities/NetInfo Manager) and navigate to /services; then change the port number of the mental ray or mental ray for Maya satellite service.

In the services file, ensure that the following line exists: ■

mental ray standalone 3.6.1: mayaray361 7009 NOTE The actual service may have a different name. Please check your services file.

■

mental ray for Maya Satellite 2009: mi-raysat2009 7109

where 7109 or 7009 is the port number. Make sure the port number is the same on the master machine and all slave machines.

Licensing of mental ray standalone (mental ray standalone) You may need to edit a file called the rayd file located in the mental ray 3.6.1 installation bin directory. Fill in the name of your SPM License server and uncomment the setenv SPM_HOST line.

Restarting the service (Windows) To restart the server on Windows, go to mental ray bin directory and type the following: ■

mental ray for Maya Satellite raysat2009server.exe /stop raysat2009server.exe /start

■

mental ray standalone rayserver.exe /stop rayserver.exe /start

inetd configuration (Linux with versions of Redhat prior to 7.2) You may need to edit the inetd.conf file located at /usr/etc/inetd.conf and ensure that the following line exists: ■

mental ray standalone: mi-ray stream tcp nowait nobody /usr/local/mi35/bin/rayd rayd

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■

mental ray for Maya Satellite mi-raysat stream tcp nowait nobody /usr/local/mi35/bin/raysatd raysatd

You may need to restart the inetd service by typing the following: % killall -v -HUP inetd

(Linux only with version of Redhat 7.2 and 7.3) You may need to edit the services in the xinetd.d directory. See To check your xinetd configuration on Linux on page 286 below. To check your xinetd configuration on Linux 1 In a Linux shell type: ls /etc/xinetd.d

There should be a file named mi-ray (mental ray standalone) or mi-raysat (mental ray for Maya Satellite). 2 If there is no such file, become root, create the mi-ray or mi-raysat file using a text editor and enter the following text: mental ray: # description: mental ray for maya network rendering service miray { flags = REUSE socket_type = stream user = nobody wait = no server = /usr/local/mi35/bin/rayd log_on_failure += USERID }

mental ray for Maya Satellite: # description: mental ray for maya network rendering service miraysat { flags = REUSE socket_type = stream user = nobody wait = no server = /usr/local/mi35/bin/raysatd log_on_failure += USERID }

3 Save the file. 4 In order for xinetd to find the newly configured service, you need to restart it or send it a signal. ■

Restarting xinetd can be undesirable because it affects a number of network services. To restart xinetd, type: /etc/init.d/xinetd restart

■

To reconfigure xinetd without restarting it, find out the process id of xinetd by executing: ps -e | grep -v grep | grep xinetd

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You should see a line similar to this: 980 ? 00:00:02 xinetd

The first number is the process id of xinetd. If the system is RedHat 7.2, xinetd re-reads its configuration on receipt of the USR2 signal. For RedHat 7.3 it re-reads its configuration on receipt of the HUP signal. So for a RedHat 7.3 system where xinetd's process id is 980 you would execute: kill -HUP 980 xinetd should have found the new service and you should be able to send it render requests from another node on the network.

How do I run multiple versions of mental ray on one machine? If you want to run different versions of mental ray standalone in one machine, make sure that each version has its own mi-ray* entry in the services file. For example, if you have mental ray 3.3 and mental ray 3.4 in one machine, and you can change the mi-ray entry for mental ray 3.3 (or 3.4). Create your own mi-ray variable for mental ray 3.3 in the services file. The services file might look like this mi-ray 7003/tcp # used for mental ray 3.4 mi-raysat 7103/tcp # used for mental ray satellite 3.4 mi-ray_33 7155/tcp # used for mental ray 3.3

The server also needs to be updated. To rename the server file (Windows) 1 Go to mental ray 3.3 bin directory. 2 Stop the service (rayserver.exe /stop). 3 Rename rayserver.exe to ray_33server.exe. 4 Restart the server (ray_33server.exe /start) To rename the server file (Linux) 1 Stop xinet. 2 Rename rayd to ray_33d.

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3 Create a new file called mi-ray33 in the xinetd.d directory. This file must contain setup information. For example: { flags = REUSE socket_type = stream user = nobody wait = no server = /usr/local/mi33/bin/ray_33d log_on_failure += USERID }

4 Restart the service.

Compatibility issues Due to a number of changes between mental ray satellite for previous versions of Maya and the current mental ray satellite, there are incompatibilities with using a master (with the current release of Maya) with slaves using a previous version of Maya.

Workaround Use master and slave machines with the same version of Maya (for example, Maya 8.5 or Maya 8.0).

Troubleshoot exporting .mi files Exporting to .mi interactively may produce incorrect results with dynamics.

Workaround Do one of the following: ■

Manually run up the scene to the current frame and export

■

Use batch export to .mi

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Appendices

8

Appendix A: Extra mental ray render settings In addition to the render options in the Render Settings window, you can also set the following render settings using MEL commands.

Render Mode You can set the render mode by using the following MEL command: setAttr mentalrayGlobals.renderMode ;

Where value is as follows: ■

0 for a full render

■

1 to render lightmaps

■

2 to render shadow maps

■

3 to render final gather maps

You may choose to render only shadow maps or final gather maps when the shadow and final gather information does not change throughout your scene. For all renders after your final gather render, set Rebuild to Off or Freeze in the Render Settings: mental ray tabs on page 404, Indirect Lighting tab on page 432, Final Gathering section, Final Gathering Map sub-section. For all renders after your shadow map render, set the Rebuild Mode to Reuse Existing Maps in the Render Settings: mental ray tabs on page 404 in the Indirect Lighting tab on page 432, Shadows section, Shadow Maps sub-section.

289

Export Verbosity You can set the verbosity level for messages from the translation process. Messages equal to or below the selected severity are displayed in the script editor. Set the verbosity level using the following MEL command: setAttr mentalrayGlobals.exportVerbosity ;

Where value is as follows: ■

0 for No Messages

■

1 for Fatal Messages Only

■

2 for Error Messages

■

3 for Warning Messages

■

4 for Info Messages

■

5 for Progress Messages

■

6 for Detailed Messages

Multiple custom state shaders mental ray installs its own state shader to perform pre- and post-shading operations like sample conversion for rendering with Maya base shaders. Custom state shaders can be chained to perform additional operations. To do so, follow these steps: 1 Ensure that miDefaultOptions exists. Otherwise, open the Render Settings window or perform a render. 2 stateShaderList is order sensitive. Append state shaders to the end as follows, where index is the size of the stateShaderList; or, reorder as needed. connectAttr "myStateShader.message" "miDefaultOptions.stateShader List[index]";

The connected nodes are translated in addition and appended to the standard Maya base state shader (if not disabled) and the potential single state shader node connected to the original stateShader attribute.

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Export includes startup file option The Export includes startup file option has been removed from the File > Export All, Export Selection (mental ray) on page 309 dialog box. To enable this option, use the following mel script: optionVar -iv "mentalrayExportStartupFileOption" 1;

With this option enabled, the exported .mi file contains an $include directive for the maya.rayrc startup file that is used by the interactive mental ray renderer in Maya. Use this option to ensure that a consistent configuration is used for rendering both with the mental ray standalone and interactively in Maya.

Appendix B: Creating camera output passes with mental ray for Maya NOTE You can use the following method for creating output passes if you are using Maya 2008 or below. Beginning Maya 2009, the recommended method is multi-render passes. You can obtain advanced control over the lighting and color values in your scene by creating camera output passes. Using this method, you can isolate the color information into separate passes, for example, RGBA in 8 bit. To create camera output passes 1 Create a camera. 2 In the camerashape node Attribute Editor, expand the mental ray section. 3 Expand the Primary Output Passes section and click the Create button to create your first output pass. The mentalrayOutputPass node appears.

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NOTE You can obtain additional control by creating an output shader and connecting it to the Output Shader field. For more information, see Output Shaders in the mental ray reference guide.

4 In the Attribute Editor for the mentalrayOutputPass node, adjust the Output Pass Options as necessary. The output pass options control data types, sampling, file mode, user framebuffers, image format and so on. For more information, see mentalrayOutputPass node on page 308.

Repeat as necessary to create multiple output passes.

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For each output pass, the output pass filename is appended to the scene render filename set in the Render Settings window. See Step 6 for more information. 5 Open the Render Settings window. Enter a filename for the scene render output. In the Renderable Cameras section, select the camera for which you created your output passes.

6 Batch render your scene. Your render output includes one image for your scene and one image for each of your output passes. For each output pass, the output pass filename is appended to the scene render output filename. For example, if you create two output passes, with the filenames output_pass_1 and output_pass_2, and your scene render file name is scene_render, then your batch render output will include the following images: scene_render, scene_render_output_pass_1 and scene_render_output_pass_2.

Appendix C:Additional mental ray for Maya rendering commands Custom render region support The image rectangle of the region render command can be controlled externally. You can do this in one of two ways. 1 Mayatomr command line option: '-rr/regionRectangle ' (integer)

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and mental ray render globals attributes: ■

'regionRectX' (integer)

■

'regionRectY' (integer)

■

'regionRectWidth' (integer)

■

'regionRectHeight' (integer)

The command option takes precedence over the globals attributes. The attributes have to be created manually on the render globals node (mentalrayGlobals). To render the specified region using the custom attributes, simply issue the 'region render' command. The extra attributes must be deleted from the globals to return to normal behavior.

Appendix D: Render layer presets If you are using the mental ray for Maya renderer, it is recommended that you use the render pass set workflow. However, render layer presets are still supported if you are using the Maya software renderer.

Work with layer presets Presets for layers set layer overrides. You can apply an existing preset to a layer, or create your own presets which you can then apply to new layers. To apply a layer preset 1 In the Render Layer editor, select a layer. 2 Select the layer in the Attribute editor, click the Preset button, and select a preset. To save a layer preset 1 In the Render Layer editor, select a layer whose overrides you want to save. 2 Select the layer in the Attribute editor, click the Preset button, and select Save Preset.

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3 In the Save Settings as Preset dialog box, enter a name for the preset. To delete a layer preset 1 From the Preset button in the Attribute editor for a layer, select Delete Preset.

Examples of presets The following examples show different presets applied from the automotive example discussed in Render layers example: automotive preview on page 298 in the What’s New in Maya guide.

Maya comes with the following presets: Preset

Description

Luminance Depth

A grayscale render based upon the depth (distance) from the camera. This produces an anti-aliased grayscale image for use in determining depth priority in a compositing application.

Example

Work with layer presets | 295

Preset

Description

Occlusion

Uses the mental ray renderer to produce an open sky-type render. Other names for this type of pass are Fake GI or Dirt shader. This pass works well with a white background.

Normal map

Renders a tangent space normal map from the renderable camera. This map can be used post 3D (compositing software) to catch highlights off the prerendered geometry. Based on the amount of red, green or blue, this map defines the rendered image's normal direction per-pixel within the color channels’ output.

Geometry Matte

A color version (black and white) of geometry's alpha or silhouette. Also known as a Mask. The Geometry Matte does not respect transparency information, as can be seen in this example (the car’s windows are transparent).

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Example

Preset

Description

Diffuse

Only diffuse shading is performed (that is, no shadow or specular information). The diffuse pass contains the diffuse and ambient information and is modulated by color, transparency, and Diffuse Coeff (diffuse coefficient).

Specular

Only specular shading is performed. The specular component is modulated differently depending on the type of material associated with the object. Phong, PhongE, Blinn, and Anisotropic materials produce specular contributions differently. On a Phong material, the specular pass can be modulated using cosine power, and specular color. No mask or alpha channel is produced for the Specular Pass; therefore, additive compositing of a specular pass is recommended.

Example

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Preset

Description

Shadow

Produces only the shadow component of the image in the alpha channel. No color information is produced.

Example

Render layers example: automotive preview Consider an example of a preview image for automotive design. The idea is to make the image look as realistically-lighted as possible, while also providing color choices for the car model. As well, it should be easy to change the background image for a variety of looks. This can be accomplished in Maya and image-editing software using render layers. In Maya, this scene has a variety of reflective surfaces and environment lighting placed around it for optimum rendering.

While working on the scene, a variety of layers are created and previewed. The final image is saved out to PSD layered format. For more details on saving

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to PSD layered format, see Render layers to PSD format on page 115. The final image contains nine composited layers: ■

There are two Beauty layers, one showing the car model with a red color, and the other showing a blue color. This can be easily done in Maya by switching the material assignment on the car objects per-layer. This allows you to quickly and easily create final images with a different car color, as all other layer contributions to the final image are the same.

■

There is a black background image (easy to replace). The beauty and background layers are ordered properly with the Normal blend mode so the beauty layers appear ‘on top’ of the background image.

■

There are luminance depth, shadow, occlusion, and specular layers created using the Maya render presets. Each contributes to the realistic lighting of the image. For more details on these presets and how they affect the final rendered image, see Work with layer presets on page 294:

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For more details on blend modes, see Layer blend modes on page 112. ■

Finally, there is a reflection layer, that is combined in image-editing software with a geometry matte layer to produce a reflection only where the car does not cover it.

The final image shows very realistic lighting as the various passes contribute their effects: the specular layer makes reflections and glow more prominent, the occlusion layer creates realistic darkening in crevasses and under geometry, and the luminance depth layer darkens parts of the image that are farther away from the camera. The shadow layer adds shadows to the car image and around the image. Finally, the reflection layer adds reflections to the model.

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Appendix E: Render Passes for Maya software renderer Work with render passes The following information is included for reference. If you are using the Maya Software renderer, we recommend that you use render layers instead of render passes. For more information see Render layer overview on page 68. If you are using the mental ray renderer, we recommend that you use multi-render passes. See Multi-render passes on page 187 for more information. When you render in passes, you render attributes of your scene differently. Rendering in passes gives you precise control over the color of objects and the shadows that fall on them. Typically you render in passes to render various attributes, such as color, shadows, highlights, of your scene separately. You can fine-tune a scene without re-rendering it by modifying different passes in a compositing program.

Beauty pass This is the default pass. You can select your render pass from the Attribute Editor of your render layer.

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It produces a complete rendering of the components produced by a shadow pass and a color pass. Because the color pass produces a complete rendering of the components produced by a diffuse pass and a specular pass, a beauty pass ends up producing a complete rendering of all possible components.

If you need to tweak shadows independently in a compositing package or paint application, run the color and shadow passes separately.

Color pass Produces only the color component of the image. No shadow information is produced. A color pass is subdivided into a diffuse and specular pass.

Shadow pass Produces only the shadow component of the image. No color information is produced.

Diffuse pass Only diffuse shading is performed. The diffuse pass contains the diffuse and ambient information and is modulated by color, transparency, and Diffuse Coeff (diffuse coefficient).

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Specular pass Only specular shading is performed. The specular component is modulated differently depending on the type of material associated with the object. Phong, PhongE, Blinn, and Anisotropic materials produce specular contributions differently. On a Phong material, the specular pass can be modulated using cosine power, and specular color.

NOTE No mask or alpha channel is produced for the Specular Pass, additively compositing a specular pass is recommended.

Custom shadow and reflection passes You can also create custom shadow and reflection passes with the useBackground material which catches shadow and, or reflections. When the shadow pass is rendered, a black image is created with mask channel that contains the shadow information. A compositor can work with this channel to blur, lighten, darken, and so on, the look of the shadows. When the reflection pass is rendered, an RGB image is created with a white mask in the mask channel. To use the Use Background material to catch shadows and reflections, see Catch shadows for an alpha channel in the Lighting guide.

Appendix F: mental ray user framebuffers mental ray for Maya user framebuffers In mental ray for Maya, you can use an unlimited number of user framebuffers. Framebuffers in mental ray for Maya are rendering attributes (color, alpha, depth, and so on) that control which image channels are passed to the shader

Appendix F: mental ray user framebuffers | 303

and in what format. For example, a 2D blur output shader might require 8-bit color, floating-point alpha, and motion vector channels. Typically, framebuffers are used in conjunction with output passes. Framebuffers can be useful to split a render into component passes that you can later composite. mental ray camera output passes can use user framebuffers to output to file.

Related topics ■

Create, edit and delete user framebuffers on page 304

■

User Buffer Attributes on page 307

■

Appendix B: Creating camera output passes with mental ray for Maya on page 291

■

Render passes on page 301

Create, edit and delete user framebuffers To create mental ray user framebuffers 1 In the Attribute Editor for the miDefaultOptions node, open the Frame Buffers section. 2 Click Create. A new mentalrayUserBuffer node appears in the Attribute Editor.

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3 Adjust the attributes for the new framebuffer as required. (See User Buffer Attributes on page 307.) The framebuffer that you’ve just created appears in the Framebuffers list in the Attribute Editor for the miDefaultOptions node. 4 Repeat the previous steps as many times as necessary. NOTE mental ray user framebuffers can be used in mental ray camera output passes to output to file. For more information, see Appendix B: Creating camera output passes with mental ray for Maya on page 291.

To edit a mental ray user framebuffer 1 Select, and right-click the framebuffer you want to edit from the Framebuffers list. 2 From the shortcut menu, select Append. The selected framebuffer appears in the Attribute Editor. 3 Adjust the attributes as required. (See User Buffer Attributes on page 307.) To delete a mental ray user framebuffer 1 Select the framebuffer you want to delete from the Framebuffers list. 2 Do one of the following: ■

Click Delete.

■

Right-click the framebuffer, and select Delete from the shortcut menu.

The selected framebuffer is removed from the Framebuffers list.

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miDefaultOptions node This node is used to access the mental ray for Maya user framebuffer functionality.

See the following for more information: ■

mental ray for Maya user framebuffers on page 303

■

Create, edit and delete user framebuffers on page 304

String options support Many features can be controlled by string options, which minimizes parse errors. You can enter the string options through the String Options section in the miDefaultOptions Attribute Editor. Each item has 3 children name, type, and value, all of type string, which provide the required information for the mental ray option. You can add more attributes by clicking the Add New Item button and a new item appears. The following keywords are recognized in the type and value fields: mray type

type string

value string

miBoolean

"bool[ean]"

'on' 'off' 'true' 'false' '0' '1'

miInteger

"int[eger]"

integer value

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mray type

type string

value string

miScalar

"scal[ar]"

floating-point value

miScalar

"float"

floating-point value

miVector

"vec[tor]"

3 floats

miColor

"col[or]"

4 floats

miString

"[string]"

string

IMPORTANT Use the miDefaultOptions node to access user framebuffer functionality and string options only. Do not use the other available settings. To set other render settings, see the Render Settings: mental ray tabs on page 404.

mentalrayUserBuffer node attributes The mentalrayUserBuffer node contains attributes that control user framebuffers. See the following sections for information on how to use framebuffers: ■

mental ray for Maya user framebuffers on page 303

■

Create, edit and delete user framebuffers on page 304

User Buffer Attributes Data Type Specifies the type of information the framebuffer contains. Select a data type from the drop-down list. For more information, see the mental ray for Maya reference in the Maya Help. Interpolate Samples This option causes mental ray for Maya to interpolate sample values between two known pixel sample values. If interpolation is turned off, the last sample value in each pixel is stored, and pixels without samples get a copy of a neighboring pixel. When this option is turned on, the resulting image has a higher quality, but takes more time to process. This option is on by default.

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mentalrayOutputPass node The mentalrayOutputPass node contains attributes that control camera output passes. For more information on mental ray camera output passes, see Appendix B: Creating camera output passes with mental ray for Maya on page 291.

Output Pass Options Renderable When on, specifies that this output pass is rendered. This option is on by default. Frame Buffer Type Specifies the type of information the pass contains. Select a data type from the drop-down list. Use User Buffer When on, specifies that a user framebuffer is used in the output pass, and activates the User Buffer drop-down list. Select the user framebuffer you want to use in this output pass. This option is off by default. User Buffer This drop-down list is available when Use User Buffer is turned on. Select the user framebuffer you want to use in this output pass. Interpolate Samples This option causes mental ray for Maya to interpolate sample values between two known pixel sample values. If interpolation is turned off, the last sample value in each pixel is stored, and pixels without samples get a copy of a neighboring pixel. When this option is turned on, the resulting image has a higher quality, but takes more time to process. This option is on by default. File Mode When on, specifies that the output pass is written to an image file, and activates the Image Format drop-down list and File Name Postfix field. Image Format Specifies the image format for the output pass, when File Mode is turned on. Select an image format from the drop-down list. File Name Postfix Specifies the operator that is appended to the end of the file name, when File Mode is turned on. Output Shader Specifies an output shader for this output pass.

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Rendering menus

9

File File > Export All, Export Selection (mental ray)

File > Export Selection, Export All > File Type When you select mentalRay from the File Type drop-down list, the many options appear.

File Type Specific Options Export Selection Output If objects do not change, reprocessing before exporting to .mi is not required, and the export process is significantly shortened as a result. Renderable Scene This is the default. Maya exports all scene entities (lights, cameras, shaders, globals, and so on) that are necessary to render the selected geometry. The resulting scene will be renderable using the mental ray standalone. Render Proxy (Assembly)

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Export selection as a mental ray file so that it can be used as a render proxy in your scene. Use this option to export your complex geometry into a mental ray file, then replace it in your scene with a placeholder object that references this file. See Using render proxies in your scene on page 242 for more information. Scene Fragment (Custom) Maya exports only the nodes that are selected. This mode can be used to export particular lights, cameras, shaders, or geometry. The resulting .mi file will most likely not be directly renderable, so it is called a Scene Fragment. Export materials In addition to the selected nodes, this setting also exports any materials that they are connected to. This applies to selected geometry and shading nodes. Export material Assignments

In addition to the selected nodes, this setting also exports any material assignment that they are connected to. For example, if your selected geometry is assigned to a Phong shader, selecting this option as well as the Export Materials option will export the geometry, its association with the Phong shader, and the Phong shader itself. This option is most useful when exporting render proxies to a .mi file. See Using render proxies in your scene on page 242Managing your scenes using render proxies on page 242for more information regarding the use of render proxies. This option supports material propagation from Maya with render proxies. For example, if you generate a render proxy without assigning to it any material or shading group, and then assign this render proxy to a shape placeholder, then any material assigned at the placeholder level (Maya shape node / instances) is automatically propagated to all objects in the render proxy file. This option allows for the separation of geometry from materials or shading groups. Export all incoming shaders In addition to selected shading nodes, also exports all inputs to those nodes. For example, if a surface shader is selected, this mode causes any texture networks feeding into the shader to be exported along with the shader.

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Export entire child DAG This option specifies that in addition to selected geometry, any children of that geometry should also be exported. The standard export filters (enabled by turning on Export Selected Items Only) are also applied to the nodes identified for export. This allows you to prevent the export of unwanted node types. Root Group Name Use this option to specify the name of the assembly root. If you choose Use Filename, the root group name is derived from the file name. For example, if the render proxy file name is test.mi, the assembly root group name is test. Alternatively, you can specify your own root group name. File Format In ASCII mode, all data in the exported .mi file will be human-readable ASCII text. In binary mode, certain floating-point data (points, normals, texture coordinates, and so on) will be output in binary format to reduce the size of the exported file. The ASCII mode tabulator size determines the amount of indentation in the .mi file. Output File Per Frame When animation is enabled, Maya exports all data required to render all the frames specified by the Render Settings animation range settings. With Output File Per Frame off, data for all the frames is output to a single .mi file. With this option on, a separate file is output for each frame. Frame Extension When Output File Per Frame is enabled, this option determines the convention for naming each frame’s output file. Frame Padding When Output File Per Frame is enabled, determines the amount of padding applied to the frame numbers. Setting the padding to 2 means each frame number is at least 2 characters long (01, 02, 03, ...), setting it to 3 means each frame number will be at least 3 characters long (001, 002, ...), and so on. Output File Per Layer The information from multiple render layers cannot be contained within a single .mi file. Enabling this option allows you to export one .mi file per render layer. If your scene contains multiple render layers, you must turn on this option. If this option is turned off and you export to .mi format, your scene will not render properly. Export File Paths Use this option to set the file path for each category. For each option, there are three choices: ■ ■

None. The filename does not contain a path. For example, hat.jpg. Absolute. The filename contains an absolute path. For example, c:/My Documents/maya/projects/default/sourceimages/hat.jpg.

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Relative to project. The relative path to the project directory is used. For example, sourceimages/hat.jpg. Link Library Path option for shader libraries. For example, decides the path options for mayabase.so, base.so, etc. Include File Path option for shader declaration files (mi) such as mayabase.mi, etc. Texture File Path option for texture files; for example, hat.jpg. Light Map Path option for lightmap files generated (if lightmap shader is used). Light Profile Path option for light profile files. Output Image Path option for output image files. Shadow Map Path option for shadow map files. Finalgather Map Path option for final gather map files. Photon Map Path option for photon map files. Render Proxy Placeholder

Path option for the render proxy placeholder. Export Selected Items Only This option allows detailed control over precisely which mental ray entities are exported into the .mi file. See the mental ray User Manual, available from the Maya Help, for descriptions of the various entity types that can be exported. Predefined Export Filters Provides several useful preset combinations of entity types for export.

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Modify Modify > Convert > Displacement to Polygons Lets you convert a displacement mapped subdivision surface to polygons to see the tessellation triangles.

Create Create > Cameras > Camera Creates a a one-node camera, which is a basic camera. For more information on the types of cameras, see Maya camera types on page 14.

Create > Cameras > Camera Create > Cameras > Camera > Camera Properties The camera viewing tools (tumble, track, and dolly) use this value to determine the “look at” point when the camera is a Basic camera. Center of Interest The distance from the camera to the center of interest, measured in the scene’s linear working unit.

Lens Properties Focal Length Also available in the camera’s Attribute Editor. The focal length of the camera, measured in millimeters. Increasing the Focal Length zooms the camera in and increases the size of objects in the camera’s view. Decreasing the Focal Length zooms the camera out and decreases the size of objects in the camera’s view. The valid range is 2.5 to 3500. The default value is 35. For more information about focal length in general, see Focus and blur on page 15.

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Lens Squeeze Ratio The amount the camera’s lens compresses the image horizontally. Most cameras do not compress the image they record, and their Lens Squeeze Ratio is 1. Some cameras (for example, anamorphic cameras), however, compress the image horizontally to record a large aspect ratio (wide) image onto a square area on film. The default value is 1. Camera Scale Scales the size of the camera relative to the scene. For example, if Camera Scale is 0.5, the camera’s view covers an area half as large, but objects in the camera’s view are twice as large. If the Focal Length is 35, the effective focal length for the camera would be 70.

Film Back Properties Don’t edit these attributes unless you are bringing in live action footage. Horizontal Film Aperture, Vertical Film Aperture The height and width of the camera’s aperture or film back, measured in inches. The Camera Aperture attribute determines the relationship between the Focal Length attribute and the Angle of View attribute. The default values are 1.417 and 0.945. Horizontal Film Offset, Vertical Film Offset Vertically and horizontally offsets the resolution gate and the film gate relative to the scene. Changing the Film Offset attribute produces a two-dimensional track. Film Offset is measured in inches. The default setting is 0. Film fit Controls the size of the resolution gate relative to the film gate. If the resolution gate and the film gate have the same aspect ratio, then the Film Fit setting has no effect. The default setting is Fill. Fill

Fits the resolution gate within the film gate.

Horizontal

Fits the resolution gate horizontally within the film gate.

Vertical

Fits the resolution gate vertically within the film gate.

Overscan

Fits the film gate within the resolution gate.

You can also set Film Fit in the camera view’s View > Camera Settings submenu.

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Film Fit Offset Offsets the resolution gate relative to the film gate either vertically (if Film Fit is Horizontal) or horizontally (if Film Fit is Vertical). Film Fit Offset has no effect if Film Fit is Fill or Overscan. Film Fit Offset is measured in inches. The default setting is 0. Overscan Scales the size of the scene in the camera’s view only, not in the rendered image. Adjust the Overscan value to see more or less of the scene than will actually render. If you have view guides displayed, changing the Overscan value changes the amount of space surrounding the view guides, making them easier to see. The default value is 1. 1

The view guide fills the view. The edges of the view guide may be exactly aligned with the edges of the view, in which case the view guide is not visible.

>1

The higher the value, the more space is outside the view guide.

Clipping Planes For information on clipping planes, see Clipping planes on page 21. Near Clip Plane, Far Clip Plane For Hardware rendering, Vector rendering, and mental ray for Maya rendering, this represents the distance of the near and far clipping planes of perspective or orthographic cameras. The default setting for Near Clip Plane is 0.1 and for Far Clip Plane is 1000. For Maya software rendering, by default Auto Render Clip Plane is on (see Auto Render Clip Plane on page 345), and the Near Clip Plane and Far Clip Plane values do not determine the position of the clipping planes. See Auto Render Clip Plane on page 345. If the distance between the near and far clipping planes is much larger than is required to contain all the objects in the scene, the image quality of some objects may be poor. Set the Near Clip Plane and Far Clip Plane attributes to the lowest and highest respective values that produces the desired result. TIP The objects you want to render are usually within a certain range from the camera. Setting the near and far clipping planes just slightly beyond the limits of the objects in the scene can help improve image quality.

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NOTE The ratio of far:near clipping planes determines the depth precision. Try to keep that ratio as small as possible for better results. Since most of the depth precision is concentrated around the near clip plane, try to avoid a lot of detail on distant objects. This concept is crucial for hardware rendering because it has only 24 bits of depth precision, as opposed to software rendering which has 32 bits.

Motion Blur Shutter Angle The Shutter Angle influences the blurriness of objects of motion blurred objects. The larger the Shutter angle setting, the more blurry objects. Shutter Angle is measured in degrees. The valid range is 1 to 360. The default value is 144. The Camera Shutter Angle option is a multiplier for the time range of the blur. Similar to traditional film and video cameras, the camera shutter angle determines the length of the exposure. However, for the purposes of motion blur, it only alters the absolute time range of the exposure based on the following equation: Blur range = (Camera Shutter Angle / 360 degrees) x Blur by Frame (In real-world film cameras, this is calculated at 180 degrees; during the other 180 degrees of rotation, the film is advanced to the next frame for exposure. Computer graphics cameras have no film.) For information on a real-world camera’s shutter angle and exposure in general, see Focus and blur on page 15. NOTE For the shutter angle setting to take effect (that is, for motion blur to appear), Motion Blur must be set for the following: ■

for the scene in the Render Settings window (for the particular renderer you are using).

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for at least one object in the object’s Render Stats section of the Attribute Editor.

Orthographic Views By default, when you create a camera from the Create menu, the view is perspective. If you want an orthographic camera view, click the Orthographic check box and change the Orthographic Width if necessary.

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The Orthographic Views attributes control whether a camera is perspective or orthographic (top, front, or side), and also lets you control the field of view for orthographic cameras. See also Viewing cameras vs. rendering cameras on page 13. Orthographic If on, the camera is an orthographic camera. If off, the camera is a perspective camera. Orthographic is off by default. TIP The default cameras are aligned to the major axis. You can create an off-axis orthographic camera by rotating the orthographic camera or changing the default tumble options and using the tumble tool. To rotate an orthographic view, in the Tumble tool’s option window, make sure the Locked setting turned off. See View > Camera Tools > Tumble Tool on page 354. Orthographic Width The width (in inches) of the orthographic camera. The width of an orthographic camera controls how much of a scene the camera can see. Changing the width of an orthographic camera has the same effect as zooming a perspective camera. TIP If you want to create a new perspective camera and get out of orthographic view mode, select Edit > Reset Settings, then click Apply.

Create > Cameras > Camera and Aim Creates a two-node camera, which is a basic camera plus an aim-vector control for aiming the camera at a specified “look at” point. For more information on the types of cameras, see Maya camera types on page 14.

Create > Cameras > Camera and Aim > See Create > Cameras > Camera on page 313.

Create > Cameras > Camera,Aim, and Up Creates a three-node camera, which is a basic camera with the aim-vector control plus an up-vector control for rotating the camera.

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For more information on the types of cameras, see Maya camera types on page 14.

Create > Cameras > Camera,Aim, and Up > See Create > Cameras > Camera on page 313.

Window Window > Rendering Editors > Render View Opens the Render View. For information about Render View, see Render View rendering on page 52.

Window > Rendering Editors > Hardware Render Buffer Opens the Hardware Render Buffer. For information about Hardware Render Buffer, see Hardware Render Buffer window on page 484.

Window > Rendering Editors > Render Settings Opens the Render Settings window. For information about Render Settings, see Render Settings window on page 376.

Window > Rendering Editors > Hypershade Opens the Hypershade. For information about Hypershade, see Hypershade window in the Shading guide.

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Window > Rendering Editors > Rendering Flags Opens the Rendering Flags window. For information about the Rendering Flags window, see Rendering Flags window on page 482.

Window > Rendering Editors > Shading Group Attributes Opens the Attribute Editor for the selected object. For information about the Attribute Editor, see Attribute Editor in the Basics guide.

Window > Rendering Editors > Multilister Opens the Multilister.

Window > Rendering Editors > mental ray > Approximation Editor Opens the mental ray for Maya Approximation Editor where you can set tessellation settings for mental ray for Maya.

Window > Rendering Editors > mental ray > Custom Text Editor Opens the mental ray Custom Text Editor. For information about the Custom Text Editor, see Custom mental ray text in the Shading guide.

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Render Some menu items are renderer-specific. For example, IPR menu items appear only for Maya software and mental ray rendering.

Render > Render Current Frame Opens the Render View window and renders the current scene.

Render > Render Current Frame > Messages Verbosity Level Controls the verbosity level for messages related to mental ray rendering. Messages equal to or below the selected verbosity are displayed. Messages are displayed in the console window.

Parallelism Auto Render Threads If Auto Render Threads is enabled, Maya automatically calculates the number of threads that should be used to best take advantage of the CPUs (or cores) on your workstation. This option is on by default. Render Threads Specifies the number of rendering threads to be used by mental ray for Maya for rendering. Use a thread for each CPU you utilize on the local host. Auto Tiling Turn on this option to automatically determine the optimal tile size at render time. Task Size Pixel width and height of render tiles.

Memory Auto Memory Limit If Auto Memory Limit is enabled, Maya dynamically calculates the memory limit prior to the start of rendering. This feature can be enabled at all times to obtain better performance. TIP For limited memory situations, this setting is recommended.

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To view the calculated value, ensure that Export Verbosity is set to Info Messages in the Verbosity Level section. The calculated Memory Limit is then displayed in the Script Editor. Memory Limit Soft limit for the memory used by mental ray. A soft limit implies that mental ray may actually use more memory than indicated. Calculate The Calculate button computes the memory setting for mental ray in the current situation, including the scene elements and their preview options and so forth. This attribute helps customers to obtain a rough estimate of the optimal memory limit for mental ray.

Network Used for network rendering only. Select one of these options to determine whether the local machine renders the scene, or whether the slaves render the scene. Render on the local machine Select this option so that the local machine participates in rendering the scene. Render on network machines Select this option so that the networked machine(s) participate in rendering the scene. This is useful in reducing the workload on the master machine while Maya is also running. TIP To render on all available machines, select both the Render on the local machine and Render on network machines options.

Render > Redo Previous Render Opens the Render View window and re-renders the scene from the previous view.

Render > IPR Render Current Frame

Opens the Render View window and IPR renders the current scene. See Interactive Photorealistic Rendering (IPR) on page 47 for more details. If you are using mental ray for Maya rendering, opens the mental ray IPR Render Options dialog box to let you set your IPR options. For descriptions of these options, see below.

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For more information on IPR rendering, see Batch renders from within Maya (UI) on page 52 in Rendering guide.

Render > IPR Render Current Frame >

Messages Verbosity Level Controls the verbosity level for messages related to mental ray rendering. Messages equal to or below the selected verbosity are displayed. Messages are displayed in the mental ray log file.

Parallelism Auto Render Threads If Auto Render Threads is enabled, Maya automatically calculates the number of threads that should be used to best take advantage of the CPUs (or cores) on your workstation. This option is on by default. Render Threads Specifies the number of rendering threads to be used by mental ray for Maya for rendering. Use a thread for each CPU you utilize on the local host. Auto Tiling Turn on this option to automatically determine the optimal tile size at render time. Task Size Pixel width and height of render tiles.

Network Used for network rendering only. Select one of these options to determine whether the local machine renders the scene, or whether the slaves render the scene. Render on the local machine Select this option so that the local machine participates in rendering the scene. Render on network machines Select this option so that the networked machine(s) participate in rendering the scene. This is useful in reducing the workload on the master machine while Maya is also running. TIP To render on all available machines, select both the Render on the local machine and Render on network machines options.

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Render > Redo Previous IPR Render Opens the Render View window and re-IPR renders the scene from the previous view. See Interactive Photorealistic Rendering (IPR) on page 47 for more details.

Render > Test Resolution The resolution at which the image renders in the Render View window. Use a reduced resolution to test render the scene to decrease rendering time. Camera Panel

Renders at the resolution of the current view.

Render Settings

Renders at the Resolution set in the Render Settings window on page 376. The default setting is 640x480.

10% Globals

Renders at 10% of the Resolution set in the Render Settings window on page 376. The default setting is 64x48.

25% Globals

Renders at 25% of the Resolution set in the Render Settings window on page 376. The default setting is 160x120.

50% Globals

Renders at 50% of the Resolution set in the Render Settings window on page 376. The default setting is 320x240.

75% Globals

Renders at 75% of the Resolution set in the Render Settings window on page 376. The default setting is 480x360.

110% Globals

Renders at 110% of the Resolution set in the Render Settings window on page 376. The default setting is 704x528.

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125% Globals

Renders at 125% of the Resolution set in the Render Settings window on page 376. The default setting is 800x600.

150% Globals

Renders at 150% of the Resolution set in the Render Settings window on page 376. The default setting is 960x720.

Render > Run Render Diagnostics Runs the Run Render Diagnostics tool. See Run diagnostics on page 166 for more information.

Render > Batch Render Runs a batch render. For more information, see Batch renders from within Maya (UI) on page 52. opens the Batch Render option dialog box to let you set options to render an animation on a local or remote computer, or on a computer with several processors. For descriptions of these options, see below. For more information on batch rendering, see Batch renders from within Maya (UI) on page 52 in Rendering guide.

Render > Batch Render > For Windows Use all available processors If on, rendering uses all processors available on the local computer. If off, rendering only uses the number of processors indicated by Number of Processors to Use. Use all available processors is off by default. Number of Processors to Use The number or processors used for rendering when Use all available processors is off. The default value is 1.

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For Linux Rendering CPU Determines whether rendering takes place on the local computer (Local) or on another computer across a network (Remote). If you select Remote, set Remote Machine name to the name of the computer you want to render on. The default setting is Local. Remote Machine Name When set to Remote, type the name of the computer on which the rendering takes place and press Enter. If you do not, the render occurs on the local machine.

For mental ray rendering Messages Verbosity Level Controls the verbosity level for messages related to mental ray rendering. Messages equal to or below the selected verbosity are displayed. Messages are displayed in the mental ray log file.

Parallelism Auto Render Threads If Auto Render Threads is enabled, Maya automatically calculates the number of threads that should be used to best take advantage of the CPUs (or cores) on your workstation. This option is on by default. Render Threads Specifies the number of rendering threads to be used by mental ray for Maya for rendering. Use a thread for each CPU you utilize on the local host. Auto Tiling Turn on this option to automatically determine the optimal tile size at render time. Task Size Pixel width and height of render tiles.

Memory Auto Memory Limit If Auto Memory Limit is enabled, Maya dynamically calculates the memory limit prior to the start of rendering. This feature can be enabled at all times to obtain better performance. TIP For limited memory situations, this setting is recommended. To view the calculated value, ensure that Export Verbosity is set to Info Messages in the Verbosity Level section. The calculated Memory Limit is then displayed in the render log.

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Memory Limit Soft limit for the memory used by mental ray. A soft limit implies that mental ray may actually use more memory than indicated.

Network Used for network rendering only. Select one of these options to determine whether the local machine renders the scene, or whether the slaves render the scene. Render on the local machine Select this option so that the local machine participates in rendering the scene. Render on network machines Select this option so that the networked machine(s) participate in rendering the scene. This is useful in reducing the workload on the master machine while Maya is also running. TIP To render on all available machines, select both the Render on the local machine and Render on network machines options.

Render > Cancel Batch Render Cancels the batch render that was launched in the current Maya session. For more information on batch rendering, see Batch renders from within Maya (UI) on page 52 in Rendering guide.

Render > Show Batch Render Opens an fcheck display window and displays the last rendered image. For more information on batch rendering, see Batch renders from within Maya (UI) on page 52 in Rendering guide.

Render > Render Using > Maya Hardware Changes the rendering mode to use the Maya Hardware renderer. For more information about Maya’s Hardware renderer, see Maya Hardware renderer on page 5.

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Render > Render Using > Maya Software Changes the rendering mode to use the Maya Software renderer. For more information about Maya’s Software renderer, see Maya Software renderer on page 4.

Render > Render Using > Maya Vector Changes the rendering mode to use the Maya Vector renderer. For more information about Maya’s Vector renderer, see Maya Vector renderer on page 8.

Render > Set NURBS Tessellation Render > Set NURBS Tessellation > With this window: ■

Maya can automatically optimize NURBS surface tessellation throughout an animation range (select Automatic (default) on page 328). This method is exceptionally powerful for scenes in which the distance between the camera and the object changes (animation), and lets you save memory (and time) and enhance performance by preventing overtessellation.

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You can manually adjust tessellation for objects that require non-default settings (select Manual on page 328). NOTE This feature only supports Maya software NURBS tessellation settings. It does not support mental ray tessellation settings.

Apply Tessellation Select one of the following options: Selected Surfaces, All Surfaces Lets you change the tessellation attributes for Selected Surfaces or All Surfaces at one time. Selected Surfaces is on by default.

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Tessellation Mode Maya automatically sets the optimal tessellation settings based on an object’s distance from the renderable camera(s), or lets you set them. To adjust tessellation settings, you need to switch to Manual Mode. NOTE Set the desired Resolution in Render Settings window on page 376 before using the Automatic Tessellation mode. Maya uses the Resolution settings to determine what tessellation level is needed to avoid nickeling. Automatic (default) Tessellation is based on the coverage and distance of the surface from the camera and the Automatic Mode settings on page 328. Objects that are either close to the camera or occupy a significant amount of screen space are automatically tessellated with more triangles. Objects that are further from the camera or are smaller have fewer triangles. Maya takes into consideration that distance changes over time if the surface or camera is animated, and tessellation is computed for a the range of frames set in Use Frame Range. Tessellation is evaluated and optimized at each frame, and the worst-case tessellation scenario requirements are determined and applied. In automatic mode, the tessellation can be computed for the current frame or the frame range from the render settings or time slider. Manual Tessellation is based whether you select Basic on page 330 or Advanced on page 330 in Manual Mode. This is the same as if you opened the Attribute Editor for each surface, and set the tessellation settings.

Automatic Mode settings Some of these settings appear and work for the Basic on page 330 settings of Manual Mode too.

Use Frame Range Available only in Automatic (default) on page 328 Mode. The tessellation computed by Automatic Tessellation depends on the distance of the surface from the camera. When the surface or camera is animated, this relationship changes over time. Generally, when the surface is closest to the camera you need the best tessellation (the most triangles). If you know which frame this is, use Current Frame on page 329. Otherwise, Maya computes this for you by running up the animation for a specified frame range, evaluates the tessellation at each frame, and sets the tessellation attributes to provide optimal tessellation.

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A progress bar at the bottom left of Maya’s window indicates the runup progress. You can also interrupt the runup for the tessellation evaluation by pressing the Esc key. During the interruption, the tessellation values are set and are valid up until the frame at which it was interrupted. Render Settings Maya uses the frame range set in Render Settings window on page 376. Time Slider Use the time slider to adjust the frame range as necessary. Current Frame Evaluates the best tessellation for the current frame.

Compute From Available only in Automatic (default) on page 328 Mode. All Renderable Cameras The default. Computes the automatic tessellation from the point of view of all renderable cameras. Current View Computes the automatic tessellation from the current view only.

Curvature Tolerance You can determine how smooth the nickeling of the tessellation needs to be. When you adjust this setting, Maya automatically sets the Chord Height Ratio on page 332 (an Advanced setting that is hidden, but automatically set in both Automatic (default) on page 328 Mode and Manual Basic Mode). In more complex scenes with many small objects, set the smaller objects to Low Quality. (This table applies only for manual mode; automatic mode sets the chord height, depending on the distance from the camera.) Low Quality Chord Height ratio = 0.987 Medium Quality (default) Some nickeling may occur, but a significantly lower polygon count is produced. Chord Height ratio = 0.990 High Quality Chord Height ratio = 0.994. Highest Quality The result is very smooth edges with no nickeling. Chord Height ratio = 0.995. No Curvature Check No attempt to smooth out nickeling is made and only the initial sampling for the tessellation is done. U Division Factor, V Division Factor Before adjusting these settings, adjust Curvature Tolerance to get the results you want. When you adjust this setting, Maya automatically multiplies the values by the Per surf # isoparms in 3D (an Advanced on page 330 setting that is hidden,

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but automatically set in both Automatic (default) on page 328Mode and Manual Basic Mode). The higher the values, the more polygons produced. The U Divisions Factor and V Divisions Factor attributes should contain approximately the same value. Use Smooth Edge Use this to increase the number of triangles only along the boundary of an object. This lets you smooth the edges or prevent cracks between shared curves of adjacent surfaces without tessellating across the entire object, which incurs a high rendering time. The higher the ratio, the smoother the edges and the higher the polygon count. If you get artifacts in highlights along curved parts of the surface close to an edge, don’t use this attribute. Smooth Edge Ratio Adds more triangles where required in areas of curvature along the edges of the surface. The edge is the boundary of the NURBS surface, where one of the U or V parameters takes on its most extreme value. (This does not address the silhouette edges based on how the object is viewed from the camera.) While extra triangles are primarily added along the edge, some are also added to the interior of the surface as needed to prevent cracking at T-junctions within the surface. The ratio is the length of the tessellated triangle and the curve of the boundary. Edge Swap Helps to divide quadrilateral surface spans into optimal triangles by swapping the two vertices on a quadrilateral used to create triangles. This is a secondary criteria, but it uses minimal resources.

Manual Mode Select one of the following options: Basic Basic settings appear when you select this option. For descriptions of these settings, see Automatic Mode settings on page 328. When you adjust Basic settings, Maya automatically sets the Advanced settings (which are hidden for simplicity) as follows (see Advanced Tessellation settings on page 331 for details): Advanced Advanced settings appear when you select this option. For descriptions of these settings, see Advanced Tessellation settings on page 331.

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Advanced Tessellation settings Available only in Manual on page 328 mode with the Advanced on page 330 option selected. If you have set the Curvature Tolerance (in either Automatic (default) on page 328mode or Manual on page 328 Basic on page 330 mode) to the highest setting and the object is still not smooth enough, use these settings to have more control over tessellation.

Mode U, Mode V These are Primary Tessellation attributes (see Primary vs. secondary tessellation passes on page 40). These settings tell Maya how to tessellate the surface. The U and V values represent the U and V parametric dimensions of the NURBS surface. You can set these values differently to produce tessellation for each direction of your surface. Per Surf # of Isoparms Ignores the number of surface spans and lets you specify the number of subdivisions you want to create. The result is a sparser number of isoparms on the surface than number of spans. Essentially, this setting pretends that everything is equally spaced. Per Surf # of Isoparms in 3D Same as Per Surf # of Isoparms, but attempts to space the isoparms equally in 3D space (instead of parametric space). Good for converting NURBS to polygons. This mode produces more evenly distributed triangles than other modes. Per Span # of Isoparms This is the most common mode. Divides each span, no matter how large or small, into the same number of subdivisions. Very small spans are divided into the same number of subdivisions as very large spans. The default setting is 3. Per span settings help to prevent cracks between joined surfaces where the spans match, which is particularly important for character building with multiple surfaces. Best Guess Based on Screen Size Creates a bounding box around the NURBS surface, projects it into screen space, and calculates the number of pixels in the space. Maya uses this number to guess at the per surface # of isoparms. The maximum value is 40. With this mode, the more screen space the object uses, the higher the value. This is not good for animation if the camera or the object is moving because the bounding box would change constantly. If the bounding box changes so does the tessellation and texture jitter as a result. (Problems with highlights may occur as well.) NOTE If you have a complicated NURBS surface and have Display Render Tessellation turned on, this setting could delay the update of the display, so be patient.

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Number U, Number V The actual values associated with Mode U, Mode V. Use Chord Height Turn on to enable the Chord Height on page 332slider value. NOTE Use the Chord Height on page 332 or Chord Height Ratio on page 332or Min Screen on page 333option, but not a combination of them. Chord Height Chord height is a physical measurement based on object space units; it’s perpendicular distance at the centre of a triangle edge to the curve that defines the surface. If the actual distance measured is greater that the Chord Height value, the triangle is subdivided. Once it is subdivided, it will be checked again against the same criteria and the process will continue until the criteria is met. Chord height is measured in Object Space. The default is 0.1. Chord Height is based on a default unit and doesn’t always work well for very small models as the chord height values on a small model will be smaller still.

When chord heights are calculated, if any are larger than 0.1, Maya subdivides the triangles and recomputes. This subdivision process continues until all triangles meet this criteria. The smaller the chord height, the better the approximation of the triangle to the surface curve. (This may be useful for industrial designers concerned with the accuracy of a model in relation to a prototype model.) NOTE Do not build models too small. Chord height is measured in Object Space. If you build models on a very small scale and then scale them up, the chord length is always relative to the object, not to World Space, which means tessellation criteria can be very expensive on small objects. For small or scaled objects, select Chord Height Ratio on page 332. Specifies the maximum distance the center of a tessellated span can be from the actual NURBS surface. Use Chord Height Ratio Turn on to enable the Chord Height Ratio on page 332 slider value. Chord Height Ratio Specifies the maximum ratio between the length of a span and the distance the center of that span is from the actual NURBS surface.

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Takes the ratio between the chord height (d) and the Distance (D) between the two points where the triangle intersects the surface, and subtracts it from 1, as shown in the equation: Chord Height Ratio = 1 - d/D

A Chord Height Ratio value of 0.997 and above produces very smooth tessellated surfaces. The default is 0.9830, which means d is very small compared to D (for example, 0.9830 = 1 - d/D). The closer to 1, the tighter the fit of the triangle to the surface.(This is best used in animations.) Use Min Screen Turn on to enable the Min Screen on page 333 box. NOTE ■

Use the Chord Height on page 332or Chord Height Ratio on page 332 or Min Screen on page 333 option, but not a combination of them.

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Don’t turn on Use Min Screen for surfaces that are moving toward or away from the camera during an animation. Min Screen on page 333 causes the tessellation to change over time and can cause unwanted displacement or texture ‘popping’.

Min Screen Bases tessellation on a minimum screen size (default, 14 pixels). All triangles created during tessellation must fit within this screen size. If they don’t, the are further subdivided until they do. This option is good for still images with a setting off 11.0. This option is not recommended for animations because the tessellation will constantly change when an object is moving, causing textures to jitter or jump because the shading for a particular pixel will have different tessellations to deal with on each frame. NOTE If you have a complicated NURBS surface and have Display Render Tessellation turned on, this setting could delay the update of the display, so be patient. Tessellates a surface based on how far it is from the camera and uses the screen space to determine how much tessellation is required (instead of object or world space). All triangles must fit within the specified area. The default is 14 pixels, which means all triangles must fit within a 14X14 pixel area on the screen. Triangles that do not meet this criteria are subdivided iteratively until they fall within the specified area. The smaller you set this value, the smaller the triangles must be to satisfy the criteria. Lowering this value can dramatically increase memory, so use caution.

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Render > Render Using > mental ray Changes the rendering mode to use the mental ray for Maya renderer. For more information about the mental ray for Maya renderer, see About the mental ray for Maya renderer on page 173.

Render > Export All Layers to Toxik 2007 Exports a composite of all layers in your scene from Maya to Autodesk Toxik.

Render > Export All Layers to Toxik 2007> Toxik User Settings The User Name, Server Name, Port Number and Database Name fields directly correspond to settings within Toxik. Enter the same information for these fields as you do in Toxik. For more information, see your Toxik user documentation.

Toxik Scene Settings Composition Name The unique name for the composition created by the plug-in. You can use a new name to create a new composition, or use an existing name to update the existing composition. Project Name The name of the Toxik project you want to use. Destination Folder The name of the Toxik destination folder you want to use. The destination folder contains the media you create when you publish a result. Render Directory Enter a file path or click the Browse button to select a location for the rendered output on the Toxik machine.

Output Settings Output Mode Specifies one of two output modes you can use depending on your Toxik setup. The default output mode is Update Toxik. Export Toxik IMSQ File Use this setting if you are not running Toxik on the same machine that Maya is running on, you should work in the Save Toxik

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Script mode; allowing you to save the Toxik script and run it on another machine where your Toxik database resides. Specify a file name and location in the File Name field. Update Toxik Use this setting if you are running Toxik and Maya on the same machine. The Update Toxik mode automatically updates the Toxik database and makes the Toxik composition available immediately. To work in Update Toxik mode, Python 2.4 is required. For more information on Python, see http://www.python.org. Specify the location of the Python executable file (python.exe) in the Python Location field. File Name Specifies the file name and location for the saved output of the plug-in export results. Only available for use with the Save Toxik Script output mode. Toxik Location Specifies the location of the Toxik executable file (toxik.exe). Only available for use with the Update Toxik output mode. Python Location Specifies the location of the Python executable file (python.exe). Only available for use with the Update Toxik output mode. Python Script Specifies the location of the python script to be used. By default the python script provided with Maya is used. You should only change the python script if you have a custom script for exporting to Toxik. Python Script Arguments Specifies any python arguments that you want to use when the script is executed. For example, you can use --verbose if you need to debug, or use --help to get all the available flags. The output of the python script arguments appears in the Maya Script Editor.

Render > Export Selected Layers to Toxik 2007 Exports a composite of selected layers (in the Render Layer Editor) in your scene from Maya to Autodesk Toxik.

Render > Export Selected Layers to Toxik 2007 > For a description of the options, see Render > Export All Layers to Toxik 2007 on page 334.

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Render > Export to Toxik 2008 Exports a composite of all layers in your scene from Maya to Autodesk Toxik.Beginning Toxik 2008, you will no longer export an IMSQ file. Instead, you will export to a Toxik project file. Note the following: ■

In order to use this functionality, Toxik 2008 must be installed along with Maya 2008 on the same system.

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Both Toxik and Maya should be of the same architecture. If the version of Toxik you are running is 32-bit, then the version of Maya you are running must also be 32-bit, and likewise for 64-bit.

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If you load the Toxik 2007 plug-in in Maya also, there will be two additional menu items under the Render menu: Render > Export All Layers to Toxik 2007 and Render > Export Selected Layers to Toxik 2007. However, these two menu items can only be used with Toxik 2007 and are not compatible with Toxik 2008.

Render > Export to Toxik 2008 > Toxik Export Options You can leave all fields blank with the exception of Toxik Install Directory. By default, Maya will give the Toxik project file the same name as your scene file and save it to the same folder as your scene file.

Toxik Scene Settings Toxik Project File Specifies the file name and location for the saved output of the plug-in export results. Composition Name The unique name for the composition created by the plug-in. You can use a new name to create a new composition, or use an existing name to update the existing composition. The composition contains all cameras, locators and so forth. This folder is not saved to disk. It is only seen by Toxik.

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Destination Folder The name of the Toxik destination folder you want to use. The destination folder contains all the compositions you have created. This folder is not saved to disk. It is only seen by Toxik. Render Layers Foldery The name of the Toxik render layers folder you want to use. The render layers folder contains all the media you have created. This folder is not saved to disk. It is only seen by Toxik. Export Cameras Choose to export all cameras or none of the cameras. Export Layers Choose to export all layers or none of the layers. Export Locators Select this option to export locators.

Configuration Toxik Install Directory Specify the parent directory of the location of the Toxik 2008 executable file (toxik.exe). You must specify this directory in order for the export feature to work.For example, on a typical Windows installation, toxik.exe is saved to: C:\Program Files\Autodesk\Autodesk Toxik 2008\program

You should therefore specify the Toxik Install Directory as: C:\Program Files\Autodesk\Autodesk Toxik 2008

Temporary File Directory Specify the location for a temporary file if you want to export to a separate Maya scene file. Render Directory Specify the location to which the frames are rendered. Toxik will search for rendered frames in this directory. Import Script Arguments Reserved for future development.

Render > Export Pre-Compositing

Select to export your render layers, passes and cameras to Toxik 2009. This option exports your elements using the same filename and settings as your previous export. If you have not performed an export previously, the default filename is scenename.precomp, and all render layers, passes and cameras in your scene are exported.

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Render > Export Pre-Compositing > Select this option to open the Export Pre-Compositing editor. Using this window, you can: ■

Export all render layers, render passes and cameras to a precomp file in Toxik

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Export selected render layers, render passes and cameras to a precomp file in Toxik

The Export Pre-compositing editor is divided into three tabs: Cameras, Render Layers, and Render Passes. Select the appropriate tab depending on the elements that you want to export. icon to expand the render layer, render camera, or render pass Use the hierarchy.

Exporting the elements A icon indicates that all elements are being exported. A that only partial elements are being exported.

icon indicates

In the following example, only the diffuse and incandescence passes are icon beside Bob (render layer) indicates that only exported. Therefore, the partial elements are being exported. NOTE Changing the camera parents (parenting and unparenting) changes the camera unique name, and breaks the precompositing workflow.

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Click the Export All or Export Selection button to export your render layers, passes and cameras to Toxik. The Export PRECOMP file window opens that allows you to enter a filename for your exported file.

Pre-Compositing Scene Anchor Use the Pre-Compositing Scene Anchor to connect the Maya scene to a Toxik master composition (scene composition). All elements in your scene are associated with a scene anchor. Unlike the scene name, which can change, for example, from version one to version two, the scene anchor does not change. All elements that belong to the same composite, for example, cameras, render passes, render layers, and so forth, should have the same scene anchor. After selecting Export All or Export Selection from the Export Pre-Compositing window, Toxik tries to find the scene composition with the specified anchor name. If such a composite does not exist, a new one is built. If the composite exists, then it is updated (depending on the import options in Toxik; there are different update/creation/recreate modes).

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NOTE You cannot perform an export without having a proper scene anchor defined. If you click the Export All or Export Selection buttons without entering a name in the Pre-Compositing Scene Anchor field, you are prompted to either define one, or use the scene name as the anchor. You should avoid using the scene name as your scene anchor since it breaks the unique connection between your Maya scene and your scene composition in your Toxik project. An exception to this rule is if you only plan to export once and do not intend to update your composition in the future. For example, if you only want to create a pre-compositing template in Toxik, then the scene anchor file is not required, since the scene anchor is only used to update an existing scene composition.

Scene Pre-Compositing Notes Use this section to identify the changes in the precomp file.

Panel menus View View > Select Camera Selects the view’s corresponding camera. The attributes for this camera appear in the Channel Box and the Attribute Editor. TIP Selecting the camera is useful if you want to edit the look-at and camera up nodes associated with the camera.

View > Camera settings Perspective If on, the camera is a perspective camera. For more information on perspective cameras, see Maya camera types on page 14. Undoable Movements If on, all camera movements, such as tumble, track, and zoom, are written to the Script Editor (MEL journal) which lets you undo or redo camera movements or copy camera movements to use them for other cameras or scenes.

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Undoable Movements is off by default, but you can still use [ and ] to undo and redo camera moves. No Gate Turns off the Film Gate and Resolution Gate display. Displays no frustum (viewable volume) when not you are not looking through the camera. This is the default. The frustum is the area or space the camera can see. Any object within the camera’s frustum shows up in images rendered from that camera’s view. See Clipping planes on page 21 for an diagram of the frustum. Film Gate Displays a border indicating the area of the camera’s view a real-world camera records on film. The dimensions of the film gate represent the dimensions of the camera aperture. The film gate does not represent the render region. You can customize the render region using the Camera Aperture and Film Fit attributes in the camera Attribute Editor. You can also set the rendering resolution using the Image Size options in the Render Settings window, and choose to lock the Device aspect ratio, or set the Device aspect ratio attribute. The film gate view guide indicates the area of the camera’s view that renders only if the aspect ratios of the camera aperture and rendering resolution are the same.

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Displays the viewable frustum according to the film back size. The aspect ratio of the window (or rendering resolution) determines what you actually see. Also sets the camera Overscan attribute to 1.5. The following illustration shows the film gate representing the maximum viewable (or renderable) area.

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Resolution Gate The dimensions of the Resolution Gate represent the rendering resolution (the region to be rendered). The rendering resolution values are displayed above the Resolution Gate in the view. You can change these dimensions in the Image Size section of the Render Settings window.

Enabling this option displays the renderable area for the current resolution specified in Render Settings window. This often specifies a more exact rendered image than the Film Gate option. Also sets the camera Overscan attribute to 2.0, so that more area outside the specified resolution can be viewed. NOTE If the aspect ratio between the film back and the resolution is the same, then the two resulting rendered images match. Gate Mask Turn Gate Mask on to change the opacity and color of the area outside a Film Gate or Resolution Gate. You can only view the effects of a Gate Mask when the Film Gate or Resolution Gate is on. You can adjust the gate mask’s opacity and color in the camera’s attributes under the Display Options.

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Field Chart Turn Field Chart on to display a grid that represents the twelve standard cell animation field sizes. The largest field size (number 12) is identical to the rendering resolution (the resolution gate). Render Resolution must be set to NTSC dimensions for this option to be meaningful. Safe Action Turn this option on to display a box defining the region that you should keep all of your scene’s action within if you plan to display the rendered images on a television screen. For more information on Safe Action, see Safe display regions for TV production on page 20. Safe Title Turn this option on to display a box defining the region that you should keep all of your scene’s text (titles) within if you plan to display the rendered images on a television screen. Render Resolution must be set to NTSC or PAL dimensions for this option to be meaningful. For more information on Safe Title, see Safe display regions for TV production on page 20.

Fill, Horizontal, Vertical, Overscan (for advanced users) The following options control the size of the Resolution Gate relative to the Film Gate. If the resolution gate and the film gate have the same aspect ratio, these settings have no effect. The default setting is Fill. Fill Fits the resolution gate within the film gate. Automatically selects a horizontal or vertical fit so that the selected image fills the render frame. Horizontal Fits the resolution gate horizontally within the film gate. Selects a horizontal fit for the selected image in the render frame. Vertical Fits the resolution gate vertically within the film gate.

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Selects a vertical fit for the selected image in the render frame. Overscan Fits the film gate within the resolution gate. Selects a slightly larger fit for the selected image in the render frame.

View > Camera Attribute Editor Opens the camera’s Attribute Editor.

Camera attributes TIP If you click the boxes at the right of some of the attributes in this editor, the Create Render Node window appears, which means you can map certain render nodes to the camera attributes. For more information on the Create Render Node window, see Create > Create Render Node in the Shading guide. Controls See Maya camera types on page 14 for information about the type of cameras: Camera; Camera and Aim; and Camera, Aim, and Up. Angle of view For more information on angle of view and how it’s affected by the focal length of the camera, see Angle of view (focal length) on page 19. TIP Try to avoid using a perspective camera with a very small angle (less than 5 degrees). Doing so may result in a much decreased depth precision, resulting in depth-fighting artifacts. Instead, try using an orthographic camera for a similar look. Focal length See Focal Length on page 313. Camera scale See Camera Scale on page 314. Auto Render Clip Plane For Maya software only. If this is on, the near and far clipping planes are automatically set so they enclose all objects within the camera’s view. (For the hardware renderer and mental ray for Maya renderers, you must set the near clip plane and far clip plane manually. You can set the planes manually for Maya software rendering too.) All objects render and depth precision problems are eliminated. Clipping planes are not visible in the views. If off, the near and far clipping planes are set to the Near Clip Plane and Far Clip Plane attribute values. Auto Render Clip Plane is on by default.

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Turn off Auto Render Clip Plane (and set the Near Clip Plane and Far Clip Plane) in the following cases: ■

to limit which objects render based on their distance from the camera if you are compositing based on depth Near Clipping Plane, Far Clipping Plane See Near Clip Plane, Far Clip Plane on page 315.

Stereo

The sections Stereo, Stereo Adjustments, and Stereo Display Controls contain the attributes for the stereoscopic camera (stereoCameraCenterCamShape node):

Stereo Select the method for computing the zero parallax plane from one of the following modes: Off Disables any eye separate, InteraxialSeparation, and Zero Parallax plane calculations on the node. This option disables the stereo effect. Converged Computes the zero parallax plane by toeing in the cameras. You can compare this effect to our focusing on an object by rotating our pupils inwards. However, a dangerous side effect may occur where you get a keystone effect on the pairs of render images, causing visual confusion in other elements in the scene. In a rendered image, our focus tends to saccade over the entire image and we are not focusing on a single object, which is not true in real life. You should only use Converged when an object is at the center of the screen with no scene elements at the render borders on either the left or right camera frustum. Off-axis (Default) Computes the convergence plane by shifting the frustum using camera film back. This is the safer way to compute stereo image pairs and avoids keystone artifacts. Parallel A parallel camera setup where there is effectively no convergence plane. This is useful for landscape settings where objects exist at effectively infinity. Interaxial Separation Distance between left and right cameras. Zero Parallax Distance on the camera view axis where the zero parallax plane occurs, in other words, the point where objects appear off screen. If an object

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is in front of the zero parallax plane, it has negative parallax and if an object is behind the zero parallax plane, it has positive parallax. In general, your object should be behind the zero parallax plane. in other words, the camera distance should be greater than the zero parallax plane value. The zero parallax value, the camera separation, and focal length are all used to determine the shift that must be applied to film back on the respective left and right cameras. The zero parallax distance is only applicable when in Off-Axis or Toe-In modes.

Stereo Adjustments Toe In Adjust Use this attribute to offset the computed toe-in effect when you are in Converged mode. This value is specified in degrees and acts as an offset to the computed toe-in. Film Offset Right Cam Controls the film offset for the right camera. Film Offset Left Cam Controls the film offset for the left camera.

Stereo Display Controls Display Near Clip Display method for the near clipping plane. Valid values are: 0: None. Display is disabled. 1: Left. Display left camera clipping plane. 2: Right. Display right camera clipping plane. 3: LeftRight. Display left and right camera clipping planes. 4: Center. Display center camera clipping plane. 5: All. Display all camera clipping planes. Display Far Clip Display method for far clipping plane. See Display Near Clip for valid values. Display Frustum Display method for frustum. See Display Near Clip on page 347for valid values. Display Zero Parallax Plane Enable this option to disable the display of the zero parallax plane. Zero Parallax Plane Color Use this attribute to set the zero parallax plane color. Parallax Plane Transparency Use this attribute to set the zero parallax plane transparency.

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Display Safe Viewing Volume Enable this option to disable the display of the viewing volume. Safe View Volume Color Use this attribute to set the viewing volume color. Safe View Volume Transparency Use this attribute to set the viewing volume transparency. Safe Stereo The intersection of the left and right viewing frustum. The scene elements visible by both frustums belong in the intersection. In general, do not place a object that can only be seen by one camera.

Film Back The Film Back attributes control the basic properties of a camera (for example, the camera’s film format: 16mm, 35mm, 70mm). Film Gate Lets you select a preset camera type. Maya automatically sets the Camera Aperture, Film Aspect Ratio, and Lens Squeeze Ratio. To set these attributes individually, set Film Gate to User. The default setting is User. Camera Aperture The height and width of the camera’s Film Gate setting, measured in inches. The default values are 1.417 and 0.945. This setting has a direct effect on the camera’s angle of view (see Angle of view on page 345). NOTE The Camera Aperture setting has no effect on the fStop. For more information on fStop, see Focus and blur on page 15. Film Aspect Ratio The ratio of the camera aperture’s width to its height. Maya automatically updates the Film Aspect Ratio (and vice versa). The valid range is 0.01 to 10. The default value is 1.5. Lens Squeeze Ratio See Lens Squeeze Ratio on page 314. Fit Resolution Gate Film fit on page 314. Film Fit Offset Film Fit Offset on page 315. Film Offset Vertically and horizontally offsets the resolution gate and the film gate relative to the scene. Changing the Film Offset produces a two-dimensional track. Film Offset is measured in inches. The default setting is 0. 1

The view guide fills the view. The edges of the view guide may be exactly aligned with the edges of the view, in which case the view guide is not visible.

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>1

The higher the value, the more space is outside the view guide.

Shake Enabled / Shake Use the Shake attributes to apply some amount of 2D translation to the filmback. A curve or expression could be connected to the Shake attribute to specify a realistic shaking effect. The Shake Enabled toggle can be used to turn the effect of the shake on and off. The Shake and Shake Overscan attributes duplicate and combine functionality with the Film Offset attributes and API. They are off by default. Shake Enabled allows the Shake attribute setting to be factored into the camera calculation. By default it is off. Shake specifies a translation on the filmback. The value is specified as a separate horizontal and vertical shake field, both of which default to zero, and are only utilized in the camera calculations when the Shake Enabled attribute is enabled. For camera calculation purposes, Shake and Film Offset provide the exact same effect. Shake provides an additional set of filmback translation inputs on the camera, with the additional feature that Shake can be turned on and off via the Shake Enabled attribute. Use the following MEL command to turn on Shake Enabled: setAttr perspShape.shakeEnabled 1;

Use the following MEL command to set the Shake attribute: setAttr perspShape.shake 0.5 0.5;

Shake Overscan Enabled / Shake Overscan Shake Overscan Enabled allows the Shake Overscan attribute to be factored into the camera calculation. It is disabled by default. Shake Overscan specifies a multiplier to the film aperture. This overscan is used to render a larger area than would be necessary if the camera were not shaking. This attribute will affect the output render. The Shake Overscan attribute is only used when the Shake Overscan Enabled attribute is set to true. By default, Shake Overscan is set to one. Use the following MEL command to turn on Shake Overscan Enabled: setAttr perspShape.shakeOverscanEnabled 1;

Use the following MEL command to set the Shake Overscan: setAttr perspShape.shakeOverscan 1.25;

Pre Scale The Pre Scale value is used in 2D effects. This value indicates the artificial 2D camera zoom. Enter a value into this field. The value is applied before the film roll.

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Film Translate The Film Translate value is used in 2D effects. This value indicates the artificial 2D camera pan. Enter a value into this field. Film Roll Pivot The horizontal pivot point from the center of the film back. The pivot point is used during rotation of the film back. The pivot is the point where the rotation occurs around. This double precision parameter corresponds to the normalized viewport. This value is a part of the post projection matrix. Vertical pivot point used for rotating the film back. This double precision parameter corresponds to the normalized viewport. This value is used to compute the film roll matrix, which is a component of the post projection matrix. Film Roll Value This specifies, in degrees, the amount of rotation around the film back. The rotation occurs around the specified pivot point. This value is used to compute a film roll matrix, which is a component of the post-projection matrix.

Film Roll Order Specifies how the roll is applied with respect to the pivot value. Rotate-Translate The film back is first rotated then translated by the pivot point value. Translate-Rotate The film back is first translated then rotated by the film roll value. Post Scale The Pre Scale value is used in 2D effects. This value indicates the artificial 2D camera zoom. Enter a value into this field. The value is applied after the film roll.

Depth of Field These attributes provide control over the camera’s focus. For more information on depth of field, see Aperture determines Depth of Field (DOF) on page 16. TIP The more out of focus an image is, the longer it takes to generate the final rendered image (that is, the post-render blur takes longer). Depth Of Field If on, some objects in the scene are sharply focused and others are blurred or out of focus, based on their distance from the camera. If off, all objects in the scene are sharply focused. Depth Of Field is off by default. Focus Distance The distance from the camera at which objects appear in sharp focus, measured in the scene’s linear working unit. Decreasing the Focus

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Distance also decreases the depth of field. The valid range is 0 to infinity. The default value is 5. F Stop The range of Camera Aperture settings which affect the Depth of Field. The lower the fStop (for example, f4) the lower amount of Depth of Field. The higher the fStop value (for example, f32) the greater amount of Depth of Field. For more information about fStop, see fStop (aperture) and shutter speed/angle on page 15. Focus Region Scale Scales the Focus Distance value. The valid range is 0 to infinity. The default value is 1.

Output Settings Controls whether the camera generates an image during rendering, and what types of images the camera renders. Renderable If on, the camera can create an image file, mask file, and, or depth file during rendering; that is, it is able to render. By default, Renderable is on for the default perspective camera, and off for all other cameras. This option is affected by the Renderable Camera option in the File Output section of the Render Settings window. For more information on the Render Settings window, see Render Settings window on page 376. Image If on (and Renderable is on), the camera creates an image file during rendering. The default setting is on. Mask If on (and Renderable is on), the camera creates a mask during rendering. A mask is an 8-bit channel (the alpha channel) in the image file that represents objects in shades of gray. Black areas represent areas where there are no objects (or fully transparent objects), and white areas represent areas where there are (solid) objects. Masks are used primarily for compositing. For image formats that do not support mask channels, the mask is stored as a separate image. For more information on mask channels, see Mask and depth channels on page 78. Depth If on (and Renderable is on), the camera creates a depth file during rendering. A depth file is a type of data file that represents the distance of objects from the camera. Depth files are used primarily for compositing. When on, the Depth Type attributes (next) are enabled. For image formats that do not support depth channels, the depth is stored as a separate image.

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For more information on mask channels, see Mask and depth channels on page 78.

Depth Type Determines how to compute the depth of each pixel. Closest Visible Depth Uses the closest object to the camera. When transparent objects are located in front of other objects, turn on “Transparency Based Depth” to ignore the transparent object. Furthest Visible Depth Most often used when a particle effect is occluded by an opaque object. Maya uses the Furthest Visible Depth to create a Depth file. Transparency Based Depth Turns on Threshold, which determines which object is closest to the camera, based on transparency. Transparency Based Depth is only enabled when you select Closest Visible Depth. TIP When transparent objects are located in front of other objects, you can turn on Transparency Based Depth to ignore the transparent object. Threshold Used when compositing multiple layers of transparency (which varies from 0 to 1). For example, if Threshold is 0.9 (the default), when transparent surfaces add up to 0.9 or larger, the surface becomes opaque. Pre-Compositing template

Use this attribute for Toxik pre-compositing. You can specify a pre-compositing template for each render layer in the Passes tab of the Render Settings window. See Toxik pre-compositing template for on page 406 and Exporting the multi-render passes for compositing in Toxik on page 233 for more information. The pre-compositing template on a layer assembles the passes. The pre-compositing template on a camera, however, assembles the layers. The default behavior, if no template is specified, is to stack the layers in a linear chain of blend nodes that follow the order and blend nodes in Maya.

Environment Control the appearance of the scene’s background as seen from the camera. Different cameras can use different backgrounds. Background Color The color of the scene’s background. The default color is black.

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NOTE The background color of a camera cannot be texture mapped. If a procedural background is required, use an image plane instead. Image Plane For Maya software and mental ray for Maya rendering. Creates an image plane and attaches it to the camera. Clicking the Create button automatically changes the focus of the Attribute Editor to include attributes for an image plane. For more information on image planes, see Create, edit, or position an image plane in the Shading guide.

Special Effects Shutter Angle Controls the blurriness of motion blurred objects. In a real-world camera, the shutter is actually a metal disk that is missing a pie-shaped section. This disk sits between the lens and the film, and rotates at a constant rate. When the missing section is in front of the film, it allows light from the lens to pass through and expose the film. The larger the angle of the pie-shaped section, the longer the exposure time, and moving objects are more blurred. Shutter Angle is measured in degrees. The valid range is 1 to 360. The default value is 144. See Shutter Angle on page 316for more information. NOTE Motion Blur must be on in the Render Settings window. For Maya software rendering, motion blur must also be set in at least one object’s Attribute Editor for the Shutter Angle to have any effect.

Display Options Controls the display of view guides in the camera’s view, and provides options for moving the camera. You can also access most of these attributes in any panel’s View > Camera Settings menu. Display Film Gate Film Gate on page 341. Display Resolution Displays a rectangle that indicates the area of the camera’s view that renders. The dimensions of the resolution gate represent the rendering resolution. The rendering resolution values are displayed above the resolution gate. See Resolution Gate on page 343 for more information. Display Gate Mask Gate Mask on page 343 Gate Mask Opacity The amount of the scene you can see through the masked area of a Gate Mask. This option is only available when Gate Mask is on.

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Gate Mask Color The color of the masked area of a Gate Mask. This option is only available when Gate Mask is on. Display Field Chart Field Chart on page 344. Display Safe Action Safe Action on page 344. Display Safe Title Safe Title on page 344. Display Film Pivot Displays of the film pivot guide when looking through the camera. Display Film Origin Displays the film origin guide when looking through the camera. Overscan Overscan on page 315

Movement Options Undoable Movements Undoable Movements on page 340. Center of Interest The distance from the camera to the center of interest, measured in the scene’s linear working unit. Tumble Pivot The point the Tumble tool pivots the camera about when Tumble Camera About is set to Tumble Pivot in the Tumble Tool settings window. Use Pivot As Local Space Enable this attribute so that the tumble tool does a local axis tumble, using the camera's tumble pivot as a relative tumble point.

Orthographic Views See Orthographic Views on page 316 for more information.

View > Camera Tools Selects one of the camera tools. For information on the camera tools, see Camera tools on page 17.

View > Camera Tools > Tumble Tool View > Camera Tools > Tumble Tool > For a description of the Tumble tool, see Tumble on page 17.

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Tumble scale Scales the speed of the camera movement. The slider range is 0.01 to 10. The default value is 1.

Tumble camera about Select one of the following options: Center of Interest The camera tumbles about its center of interest. Tumble camera about is set to Center of interest by default. Tumble Pivot The camera tumbles about its pivot point. This tumble pivot can also be set in the camera’s Attribute Editor (see “Tumble Pivot” for details). These values are stored in world space coordinates. View operations such as Frame Selection, Frame All, Look at Selection, Default Home, and Bookmarks all set the tumble pivot.

Orthographic views Select one of the following options: Locked If on, you cannot tumble an orthographic camera. If off, you can tumble an orthographic camera. Locked is on by default. Stepped If on, you can tumble an orthographic camera in discrete steps. The Stepped operation lets you easily return to the Default Home positions. If off, you can tumble an orthographic camera smoothly. Stepped is only available if Locked is off. Stepped is on by default. Ortho step The angle of steps (in degrees) that you can tumble an orthographic camera when Locked is off and Stepped is on. The valid range is 0.01 to 180. The default value is 5.

View > Camera Tools > Track Tool > For a description of the Track tool, see Track on page 17. TIP You can also press Alt+middle-drag to use the Track tool. Press the Shift key to constrain movement in horizontal or vertical directions. Track Geometry If off, as the camera moves an object moves at a speed that may be different than the speed of the cursor. This problem occurs with objects far from the camera. Track Geometry is off by default. If on, as the camera moves, an object moves at the same speed as the cursor. The object selected at the beginning of the Track operation remains under the cursor. Tracking is slower (especially if there are many objects in the scene) if Track Geometry is on.

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Track Scale Scales the speed of the camera movement. The slider range is 0 to 100. The default value is 1.

View > Camera Tools > Dolly Tool > For a description of the Dolly tool and tips on how to use it, see Dolly on page 17. Scale Scales the speed of the camera movement. The slider range is 0.01 to 10. The default value is 1.

Dolly Select one of the following options: Local If on, drag in the camera’s view to move the camera toward or away from its center of interest. If off, drag in the camera’s view to move both the camera and its center of interest along the camera’s sight line. Local is on by default. Center of Interest If Center of Interest is on, middle-drag in the camera’s view to move the camera’s center of interest toward or away from the camera. If off, drag in the camera’s view to move the camera toward or away from its center of interest. drag a region and snap the center of interest to the center of those objects. Center of Interest is off by default. If Center of Interest (and, or Local) and Bounding box are on, when you drag in the views, a red line with a small x at the end points to indicate the Center of Interest. Snap box dolly to A box dolly moves the center of interest to the marquee region when you use the Ctrl+Alt+drag method to dolly the camera. Surface If on, when you perform a box dolly (Ctrl+drag) on an object, the center of interest moves onto the surface of the object. Calculating the surface point is slower if Smooth Shade mode is off (and especially if there are many visible objects in the scene). Bounding box If on, when you perform a box dolly (Ctrl+drag) on an object, the center of interest moves to the center of the object’s bounding box. Bounding Box is on by default.

View > Camera Tools > Zoom Tool > For a description of the Zoom tool, see Zoom on page 18. Zoom Scale Scales the speed of the camera movement. The slider range is 0.01 to 3. The default value is 1.

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View > Camera Tools > Roll Tool > For a description of the Roll tool, see Roll on page 18. Roll Scale Scales the speed of the camera movement. The slider range is 0.01 to 10. The default value is 1.

View > Camera Tools > Azimuth Elevation Tool For a description of the Azimuth tool, see Azimuth Elevation on page 18. Scale Scales the speed of the camera movement. The slider range is 0.01 to 10. The default value is 1. Rotation type Controls whether the camera movement is an Azimuth Elevation movement or a Yaw Pitch movement. TIP Press Shift to constrain the camera’s movement.

View > Camera Tools > Yaw-Pitch Tool > For a description of the YawPitch tool, see Yaw-Pitch on page 18. Scale Scales the speed of the camera movement. The slider range is 0.01 to 10. The default value is 1. Rotation type Controls whether the camera movement is a Yaw Pitch movement or an Azimuth Elevation movement. TIP Press Shift to constrain the camera’s movement.

View > Image plane Provides you with options to import a file to use an image plane and access the Image Plane’s attributes. For more information on image planes, see Create, edit, or position an image plane in the Shading guide. Import Image Import a file to use as an image plane. Image plane attributes Access the image plane’s attributes.

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Stereo Stereo > Center Eye

Look through the center stereo camera. This is the default option.

Stereo > Active

Use your graphics card for stereo viewing. If you are using the NVidia Quadro line graphics cards, and you have turned on stereo mode, the Active menu becomes live. The CRT monitor uses the page flipping method of stereo imaging. The settings that you have chosen for your stereo mode in your graphics card are respected; for example, the DIN connector will send signal to your 3D glasses.

Stereo > Horizontal Interlace

This viewing mode interlaces one row of pixels from the left camera with one row of pixels from the right camera and so forth. You obtain half the vertical resolution through this mode. Select this mode for polarized LCD monitors.

Stereo > Checkerboard

This viewing mode alternates between one pixel from the left camera with one pixel from the right camera, forming a checkerboard pattern. You obtain

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half the vertical resolution and half the horizontal resolution through this mode. Select this mode for Samsung DLP 3D displays.

Stereo > Anaglyph

Maya supports the red/cyan anaglyph mode. Maya composites the color output from the left camera with the color output from the right camera.

Stereo > Luminance Anaglyph

The Luminance Anaglyph mode is similar to the Anaglyph mode, but the color output from the left and right cameras are first converted to greyscale before being composited on top of each other.

Stereo > Freeview (Parallel)

Select this mode to see the left and right camera output side by side in the same window.

Stereo > Freeview (Crossed)

This mode is similar to Freeview (Parallel), but the left camera output is displayed on the right while the right camera output is displayed on the left.

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Stereo > Background Color

Black is the default background color for stereo mode. Choose this option to select an alternate background color from the Color Chooser.

Stereo > Set Color Using Preferences

Black is the default background color for stereo mode. Select this option to use the background color you have set in Window > Settings/Preferences > Color Settings instead.

Renderer Renderer > Default Quality Rendering Select Default Quality Rendering when you do not require a high quality render but wish to reduce draw time in the scene view and increase efficiency. When this option is turned on, the scene views are drawn with low quality settings by the hardware renderer.

Renderer > High Quality Rendering When high quality interactive shading is turned on, the scene views are drawn in high quality by the hardware renderer. This lets you see a very good representation of the look of the final render without having to software render the scene. The following is not supported: ■

motion blur

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software multi sampling

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TIP If you require faster playback or camera tumbling while using Maya’s High Quality shading, turn on Interactive Shading (Shading > Interactive Shading).

To turn on high quality shading 1 Make sure smooth shading (or higher) is on (press 5, 6 or 7). 2 In the desired scene view, select Shading > High Quality Rendering.

Renderer > High Quality Rendering > These are descriptions of the options in the Hardware Renderer Display Options window.

Display Quality Low Quality Lighting Low quality lighting is essentially per-vertex lighting, which calculates light only on vertices, then blends the results. Renders are faster and of reasonably good quality. Match Viewport Lights When turned on, only as many lights as are supported by the graphics card (typically 8 lights) are used. Transparent Shadow Maps Those regions of an object which are fully transparent will not cast a shadow. For example if you map the transparency channel of a shader (on an object) to a checker texture the fully transparent portions of the object would not cast a shadow.

Display Parameters Occlusion Culling This option improves performance for scenes with many objects, where one or more objects can be obscured from the viewpoint of the active camera. When turned on, this option increases performance by preventing out-of-view objects from being drawn. Culling Override Every position on a surface has a normal which points in the direction that is considered (for culling purposes) to be the "front side" of the surface. ■

Single sided means the surface is illuminated by a light if that normal is visible from the light.

■

Double sided means that the surface is illuminated on the front and the back sides.

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Color Texture Resolution If hardware rendering cannot process a shading network on board the graphics hardware, the shading network is evaluated and converted to a file texture (2D image) that the hardware renderer can use. This option specifies the dimension of the resulting texture. Affected channels are color, incandescence, ambient, reflected color, and transparency. The default value is 128, which means that any baked color images will have a dimension of 128 by 128 pixels. Bump Texture Resolution If hardware rendering cannot directly process a shading network on board the graphics hardware, the shading network is evaluated and converted to a file texture (2D image) that the hardware renderer can use. This option specifies the dimension of the resulting texture. The default value for this option is 256, which means that any baked bump images will have a dimension of 256 by 256 pixels.

Renderer > You now have the ability to write your own plug-in and override the scene view renderer with the interactive renderer that you created. Once you have loaded your plug-in via the Plug-in Manager, the name of your custom renderer will appear under the Renderer Panel menu (for example, Renderer > openGLViewport Renderer). If you choose to load multiple custom renderers, they will be listed in the order that they are loaded. Two example plug-ins have been provided with the SDK, one for OpenGL and one for Direct 3D. (Note that these example plug-ins have not yet been compiled and need to be compiled before they can be accessed via the Plug-in Manager.) For more details on API classes that can be used to create these plug-ins, see the API Guide in the Maya documentation.

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10

Approximation Editor mental ray Approximation Editor Window > Rendering Editors > mental ray > Approximation Editor Derive from Maya The default setting for mental ray for Maya approximation (see also Derive from Maya (default approximation) settings on page 181). This setting uses the Fine displacement approximation setting. This advanced technique produces memory-efficient tessellations that capture extremely fine details in displacement maps. By default, the algorithm is set to use a view-dependent technique that tessellates details as small as 1 pixel across.

Surface Approximation settings (Attribute Editor) The following settings appear when an approximation node is selected in the Approximation Editor, or when an object to which an approximation node has been assigned is selected in the scene view. Most of these settings are similar to other types of approximation nodes: trim curve, and displacement approximations.

Presets This drop-down list provides many useful preset tessellation settings.

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You can select an item from this list to load the preset values for the approximation node's attributes. You can use these settings as-is, or as a starting points for tweaking. By default, the Presets tab is set to Custom, which means that you have control over all approximation attributes. Parametric Grid (Low/Mid/High) Quality Uses the Parametric approximation method to tessellate a surface into triangles. With this method, each patch (area between isoparms) is subdivided into a fixed number of triangles. Use this preset to produce tessellations where triangles are distributed roughly according to the spacing of isoparms on the surface, with closer isoparms producing higher triangle densities. Regular Grid (Low/Mid/High) Quality Uses the Regular Parametric approximation method, where the surface as a whole is subdivided into a fixed number of triangles (instead of each patch, as is the case with the Parametric method). Use this preset to ensure an even triangulation over surfaces where the spacing of isoparms is uneven. Angle Detailed (Low/Mid/High) Quality Uses an adaptive tessellation method in which more triangles are added to areas of high curvature. The goal of this method is to add triangles where they are needed to capture sharp features, while at the same time using just a few triangles in large, flat areas where they are not needed. Pixel Area (Low/Mid/High) Quality Tessellates surfaces based on their size (in pixels) in the final rendered image. Surfaces that are close to the camera will be tessellated heavily, while surfaces that are far away from the camera will receive coarser tessellations. The goal of this preset is to focus the most attention on surfaces that are more significant to the final image.

Approx Style Determines the general subdivision scheme that is used to break the surface into triangles. For examples, see Approximation styles on page 183. Grid Works on a grid of isolines that allows subdivision only by adding more isolines. Since isolines always run from one edge of the surface to the opposite edge, and since only whole isolines can be added, this produces regular triangle meshes which can sometimes contain many more triangles than necessary. Tree Specifies a hierarchical subdivision style that allows local subdivisions without affecting other areas. The local subdivisions are similar to the Grid method, but do not cross over to other surface patches. Delaunay Specifies a mesh refinement technique based on Delaunay triangulation, which attempts to maximize triangle compactness and to avoid

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thin triangles. Triangle vertices are generally not restricted to rectangular isoline grid points as in the Grid and Tree styles. The Delaunay style is supported only for free-form surfaces (NURBS), not for polygons. The "Max Triangles" and "Grading" attributes can be used to fine-tune tessellations using the Delaunay style. Fine Subdivides surfaces into a large number of roughly uniformly-sized small triangles in order to guarantee a smooth result. To deal with the large number of triangles resulting from this approximation style, mental ray breaks the surface up into independent sub-objects that are each tessellated and cached separately. This allows the tessellator to generate a large number of triangles without incurring a huge memory cost. This approximation style is similar to the one used by Pixar® Renderman® software, and only supports the "Spatial" approximation method, which specifies the size of triangles to be generated.

Approx Method Determines the criteria that the tessellator uses for determining when to subdivide a part of the surface. Some approximation methods simply break the surface into a fixed number of triangles, while others use adaptive criteria to iteratively add more and more triangles until some condition is satisfied. Parametric This method is driven solely by the "U Subdivisions" and "V Subdivisions" attributes. Each patch is subdivided into N triangles, where N = (U Subdivisions) * (V Subdivisions) * degree^2 * 2 Thus, with U Subdivisions set to 1.333 and V Subdivisions set to 4 on a degree-3 NURBS surface, each patch will be subdivided into 1.333*4*3*3*2 = 96 triangles. Regular Parametric This method is also driven solely by the "U Subdivisions" and "V Subdivisions" attributes. With this method, though, the surface as a whole is subdivided into N triangles, where N = (U Subdivisions) * (V Subdivisions) With this method, the density of triangles will be constant over the entire surface, unlike the Parametric method, which tessellates each patch independently. Length/Distance/Angle This is an adaptive approximation method, meaning that the tessellator continually subdivides the surface until certain criteria are met. There are 3 criteria: Length: Subdivide until no triangle has an edge longer than a certain length. The Length attribute is used to specify this desired edge length. If the View Dependent attribute is turned on, this value is specified in pixels, otherwise it is specified in object-space units. The Length criterion is especially useful in conjunction with view dependency, for example a view-dependent value of Length=0.5 means subdivide until all triangles are no bigger than half a

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pixel in the resulting image. If the Length attribute is set to 0.0, this criterion is ignored by the tessellator. Distance: Subdivide until the resulting triangles are at no point further than a certain distance away from the exact NURBS surface. The Distance attribute is used to specify the desired distance. If the View Dependent flag is turned on, this distance is expressed in pixels, otherwise it is expressed in object-space units. The lower the value, the more closely the tessellated surface will match the exact NURBS surface. Small values such as 0.1 work well (with view dependency disabled). If the Distance attribute is set to 0.0, this criterion is ignored by the tessellator. Angle: Subdivide until the normals of neighboring triangles form an angle of less than a certain tolerance. The Angle attribute specifies the angular tolerance. The Angle value should be chosen carefully, as small values can cause the number of triangles to increase rapidly. 45 degrees is a good starting point. If this value is set to 0.0, then this criterion is ignored by the tessellator. There are several other attributes that influence the Length/Distance/Angle approximation method: View Dependent: When enabled, means that the Length and Distance attribute values are assumed to be expressed in pixels. Otherwise, these values are assumed to be expressed in object-space units. The advantage of using view-dependent values is that objects that are close to the camera will receive many triangles, while objects that are far away (or not visible at all) will be approximated much more coarsely. Any Satisfied: When more than one of the Length/Distance/Angle criteria are enabled, this flag determines when subdivision will stop. If Any Satisfied is enabled, then subdivision stops when any one of the criteria is satisfied (for example, triangles are smaller than a certain size or distance from the surface is less than a certain amount or angles between triangles are less than a specified amount). If Any Satisfied is disabled, then subdivision continues until all criteria are satisfied (for example, triangles are smaller than a certain size and distance from the surface is less than a certain amount and angles between triangles are less than a specified amount). Spatial The Spatial approximation method is the same as the Length criteria from the Length/Distance/Angle method. Using this method, the mesh will be subdivided until all triangles are less than a certain size, determined by the Length attribute. This value is expressed in either pixels or object-space units, as determined by the View Dependent flag. This method is the only one available when using the Fine approximation type. Curvature This approximation method is the same as the Distance and Angle criteria from the Length/Distance/Angle method. This method is included for backwards compatibility only.

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Render Layer Editor

Window > Rendering Editors > Render Layer Editor

From the Render Layer Editor, you can create, manage, and delete layers, layer blends, and layer overrides. You can also create render pass contribution maps for your render layers. A render pass contribution map is a subset of the objects in your render layer that you can create render passes for. NOTE The multi-render pass feature is supported for the mental ray renderer. The rendering API allows other 3rd party renderers and custom renderers to support it moving forward. You can open the Render Layer Editor in a separate window or view it in the same docked area as the Channel Box. To open the Render Layer Editor in a new window, select Layers > Floating Window.

The general workflow for using the Render Layer Editor is as follows:

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Create layers

Click the icons at the top to create a new layer assign selected objects

, or create a layer and

.

Ordering of layers Render layers are ordered based on their compositing order. The bottom of the list are the background elements, and the top of the list are the front most elements. The render layer compositing order can only be edited from the Render Layer Editor.

Use the up and down buttons to move render layers up and down. The buttons are only active if a single render layer is selected. You can also use the middle mouse button to drag the layers up and down.

Per layer overrides Follow these guidelines to perform per layer overrides: ■

between red and On any previously rendered layer, toggle this icon green to re-render the layer or to recycle the previously rendered image. To reuse the last rendered image for this layer, toggle this icon to green . To re-render the selected layer, toggle this icon to red

.

NOTE

■

■

This feature is applicable only if the selected layer has been rendered at least once. The recycle icon remains grey until a recyclable image is available.

■

Render output is only held in memory for your current session of Maya. Any render output is lost after you quit and restart Maya.

(controls) to display render settings (including which Click this icon renderer is selected) for that layer. If there’s a renderer override, this icon becomes an active controls icon. NOTE Individual, per object overrides are not shown in this interface.

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Previewing layers ■

Select a blend mode for each layer from the drop-down list.

■

The Render All Layers option (Options > Render All Layers) selects whether all layers are composited and rendered to the Render View, or whether just the selected layer is rendered. In the options for this command (Option > Render All Layers > ), you can further select whether to show the composite image, the composite image and the individual rendered layers, or just the individual rendered layers.

■

Click the or not.

icon next to each layer to set whether a layer is renderable

Render pass contribution maps You can create render pass contribution maps for each render layer. For example, if your render layer consists of 5 objects and 2 lights, you can create a diffuse pass, an ambient pass, and a specular pass for only 3 of the objects and 1 of the lights. To do so, create a pass contribution map containing the 3 objects and the light that you would like to create your diffuse, ambient and specular pass for. You can create multiple pass contribution maps for each render layer. You can also share pass contribution maps between render layers. icon to expand or collapses the list of pass contribution maps Click the associated with the selected layer. This icon appears after you have associated a pass contribution map with the layer.

Render Layer Editor menus Layers menu Create Empty Layer Creates a new render layer, depending on the selection in the pull-down menu, with a default name, for example layer1. Create Layer from Selected Creates a new render layer and populates it with the selected objects.

Copy Layer > Duplicates the selected layer. There are two options available with this feature:

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With membership and overrides Select this option to copy both the objects and render layer properties to the new layer. With membership Select this option to copy only the objects to the new layer and create new overrides for the duplicated layer. Select Objects in Selected Layers Selects the objects contained in the selected layer(s). Remove Selected Objects from Selected Layers Removes selected objects from the selected layer(s) Membership Opens the Relationship Editor for removing or adding objects to layers. Attributes Opens the Attribute Editor for the selected layer(s). There are some attributes in the Attribute Editor not available through the Edit Layer window. Delete Selected Layers Deletes the selected layer(s), but not the objects in the layer. Delete Unused Layers Delete layers if they have no content. Floating Window Select this option to open a separate, floating Render Layer Editor window.

Contribution menu You can create your render pass contribution maps using this menu. Create and Associate Pass Contribution Map Create a new pass contribution map and associate it with the selected layer. Associate Existing Contribution Map The submenu provides a list of pass contribution maps available in the scene. Select the desired contribution map to associate it with the current layer. Copy Pass Contribution Map Duplicate your selected contribution map. Select Objects in Selected Pass Contribution Maps This option indicates which objects belong in the selected pass contribution maps. All objects in the pass contribution map are selected. Add Selected Objects to Selected Pass Contribution Maps Use this option to add the selected objects to the selected pass contribution maps. Remove Selected Objects from Selected Pass Contribution Maps Use this option to remove objects from the selected pass contribution maps.

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Delete Selected Pass Contribution Maps To remove a pass contribution map or multiple pass contribution maps, select the map(s) and then choose this option. Delete Unused Pass Contribution Maps Pass contribution maps that do not have geometries and lights assigned to them are removed with this option. Membership Opens the Relationship Editor window. Attributes Opens the pass contribution map Attribute Editor.

Options menu You can set the following binary options: ■

Make New Layers Current

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Add New Objects to Current Layer

■

Auto Overrides

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Show Namespace Render All Layers Renders all the layers in the scene based on the default Render All Layers Options.

Render All Layers > Select one of the following options: Composite layers Renders a composited result of all layers and displays it in the Render View. This is the default for Render All Layers. Composite and keep layers Renders all your layers as individual images, but displays a composited result. Keep layers Renders all your layers as individual images. NOTE Using Keep layers significantly increases memory usage in Maya. Consecutive use populates the Render View with more and more images. You must clear out images manually as needed.

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Auto Overrides The Auto Overrides option simplifies the workflow for creating layer overrides for attributes such as Casts Shadows, Receive Shadows, and Visible in Reflections. The Auto Overrides option is applicable to the following attributes: ■

■

Under the Render Stats section (of the Attribute Editor) of the object's shape node: ■

Casts Shadows

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Receive Shadows

■

Motion Blur

■

Primary Visibility

■

Visible In Reflections

■

Visible In Refractions

Under the Display section (of the Attribute Editor) of the object's transform node: ■

Visibility

When the Auto Overrides option is on, you can simply click on each of these attributes and an override will be created for the selected layer. Upon being unchecked, the attribute name immediately turns orange to indicate that a layer override has been created. This eliminates the need to right-click the attribute and select Create Layer Override.

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TIP If your scene contains a lot of surfaces, you can also use the Attribute Spread Sheet to create a layer override. As in the case of the Attribute Editor, when the Auto Overrides option is on, you can simply change the setting for each of the attributes and a layer override is automatically created.

This feature is most useful when there are multiple objects/layers in the scene for which overrides need to be created. This feature simplifies the workflow by eliminating the need to select Create Layer Override. Show Namespace When using namespaces, object names can sometimes get very long. This can make it difficult to differentiate objects by name. Turning off the display of namespaces replaces the namespace portion of a node’s name (if any) with “...:”. The shortened name makes it easier to distinguish between different objects in your scene. NOTE Namespaces are the preferred method for managing naming when working with file references in Maya. It is not recommended that you employ Maya's renaming prefix convention when using file referencing. While the DAG path or long name of a node may make it unique when using renaming prefixes, they do not work consistently within file referencing and complicate the hierarchical DAG changes, which may cause problems later on.

Render Layer Editor Context-sensitive menus Context-sensitive menu for render layers The following commands are available when you right-click a layer: Add Selected Objects /Remove Selected Objects Add or remove objects from a render layer. Select Objects in Layer Selects objects that belong to the current layer. Empty Render Layer Removes all objects from a layer, leaving it empty.

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Copy Layer Duplicates the layer. Delete Layer Deletes the layer. Overrides Expand the submenu to select the desired override. Remove Render Setting Overrides Removes any render setting overrides for the current layer. For more information, see Work with layer overrides on page 102. Remove Render Flag Overrides Removes any render flag (layer attributes) overrides for the current layer. For more information, see Work with layer overrides on page 102. Remove Material Override Removes the current material override for the select object(s) on the current layer. For more information, see Work with layer overrides on page 102. Create New Material Override Allows you to select a new material override for the current layer. For more information, see Work with layer overrides on page 102. Assign Existing Material Override Allows you to select an existing material override for the current layer. For more information, see Work with layer overrides on page 102. Pass Contribution Maps Expand the submenu to choose among one of the following options. Create Empty Pass Contribution Maps Create a new empty contribution map for the selected layer. Create Pass Contribution Maps and Add Selected Create a new contribution map for the current layer containing the selected objects. Associate Existing Pass Contribution Maps The submenu provides a list of pass contribution maps available in the scene. Select the desired contribution map to associate it with the current layer. Add New Render Pass Allows you to add a new render pass to your layer. Expand the submenu to choose among one of the available render passes. Membership Opens the Relationship Editor for removing or adding objects to layers. Attributes Opens the Attribute Editor for the selected layer(s). There are some attributes in the Attribute Editor not available through the Edit Layer window.

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Context-sensitive menu for pass contribution maps The following commands are available when you right-click a render pass contribution map. NOTE Pass contribution maps can be shared between several render layers. In this case, removing a geometry or light from a pass contribution map in one layer also removes it from the same contribution map in the other layers. Therefore, you should exercise caution if you change the membership of a pass contribution map that is shared between layers. To avoid this problem, create separate pass contribution maps for each render layer.

Select the pass contribution map name to display its Attribute Editor. Add Selected Objects / Remove Selected Objects Add or remove objects from both the render layer and the current pass contribution map. Select Objects in Pass Contribution Map This option indicates which objects belong in the current pass contribution map. All objects in the pass contribution map are selected. Remove Pass Contribution Map from Layer Remove render pass contribution map from the current layer. Empty Pass Contribution Map Remove all objects from render pass contribution map. Delete Pass Contribution Map Removes render pass contribution map from all layers.

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Active Sets the pass contribution map as active so that it is respected when render passes are created. Add New Render Pass Allows you to add a new render pass to your render pass contribution map. Expand the submenu to choose among one of the available render passes. Membership Opens the Relationship Editor for removing or adding objects to layers.

Render Settings Render Settings window Window > Rendering Editors > Render Settings

Render settings (scene settings) for the Maya Hardware renderer, the mental ray for Maya renderer, the Maya Software renderer, the Maya Vector renderer are consolidated into one Render Settings window. Use the settings in this window to set scene-wide render options. Especially when used in conjunction with per-object render settings (see the particular object or render subject matter for details), the render settings give you a great deal of control over quality of rendered images and the speed with which they are rendered. To open the Render Settings window, see Open the Render Settings window on page 84.

Render Layer Select from the drop-down list the layer that you want to render from.

Render Using Select from the drop-down list the renderer that you want to use.

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Common tab The common tab contains settings that are common to all renderers. For information on the Common tab, see Render Settings: Common tab on page 377.

Render-specific tabs The other tab changes, depending on which renderer is selected. ■

For information on the Maya Software tab, see Render Settings: Maya Software tab on page 388.

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For information on the Maya Hardware tab, see Render Settings: Maya Hardware tab on page 454.

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For information on the mental ray for Maya tabs, see Render Settings: mental ray tabs on page 404.

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For information on the Maya Vector tab, see Render Settings: Maya Vector tab on page 459.

Render Settings: Common tab

For information on the render settings, see Render Settings window on page 376. Not all options are available for all renderers.

File Output The name of rendered image files can consist of three separate components: file name, frame number extension, and file format extension. A combination of these three components is referred to as the file name syntax. File name prefix Right-click the File name prefix attribute to add one or more of these fields to the file name for your scene, for example, scene name, layer name, camera name, version number, current date or current time. Each of these fields are described in more detail below.

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You can also create subdirectories to save out rendered images by adding a / (slash) in your file name prefix. For more information about the file name syntax, see Subfolders and names of rendered images on page 60. NOTE When choosing basic file names for an animation, avoid using periods; use underscores instead. For example, use: xxx_yyy.iff.1

instead of xxx.yyy.iff.1

Select this render token to add the scene name to your output file name. Select this render token to add the render layer name to your output file name. Select this render token to add the camera name to your output file name.

When rendering using passes, you can group render passes into logical file groups. Each render pass node has an attribute Pass Group Name that allows you to create a logical group. Select this render token to add the Pass Group Name to your output file name. See Render pass Attribute Editor on page 501 for more information. NOTE The multi-render passes feature is not supported for the Maya Software renderer and these tokens will be replaced with an empty string.

Select this render token to add the render pass node name (for example, diffuseNoShadow) to your output file name (for mental ray rendering only).

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Many different types of render passes are available for selection using the Render pass Attribute Editor on page 501, for example, beauty, shadow, specular, refraction, and so forth. When you use this render token, a unique abbreviation of the pass type, of less than 6 characters, is appended to your output file name, for example, REFR for refraction pass.

Select this render token to add the extension to your output file name. In many cases, you do not need this token, since the file extension is automatically appended by Maya. However, you may want to create a directory structure using the file type. For example, if you are using the.iff format, /_ can create files such as the following: images/iff/bob_camera1_diffuse.1.iff . Select this render token to add the version to your output file name. You can set your version using the Version Label attribute. current date Select to add the current date to your output file name. This field is not dynamic and captures the date and time at the moment that the token is inserted. Therefore, the date and time does not update once the token has been inserted. current time Select to add the current time to your output file name. This field is not dynamic and captures the date and time at the moment that the token is inserted. Therefore, the date and time does not update once the token has been inserted. Image format The format for saving rendered image files. See also File formats on page 53. The default setting is Maya IFF. NOTE Among the available multi-channel file formats, OpenEXR is the only file format where multi-channel is being leveraged. When using the multi-render pass feature, you can concatenate multiple render passes into a single multi-channel .exr file. Upon selection of the OpenEXR format, the Frame Buffer Naming option becomes active. Select the Automatic option to name each pass using the :. tokens, or, choose Custom to select the render tokens of your choice. See Frame Buffer Naming on page 380 for more information.

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Compression... Click this button to select the compression method for AVI (Windows) or Quicktime movie (Mac OS X) files. When you click this button, the Video Compression dialog box appears. Select the desired compression method from the Compressor drop-down list. Currently, Maya only supports the Uncompressed and Cinepack Codec compression methods. This button only becomes active when you select AVI (Windows) or Quicktime movie (Mac OS X) as your image format (for Maya Software renderer only). NOTE The settings for this option are saved in the Windows registry and not in the scene file. Copying a scene file from one machine to another does not transfer these settings. Frame/Animation ext The format (syntax) of rendered image file names. This attribute can be used to determine if a static image is to be rendered or a sequence. If the latter, several presets are available for you to choose how the frame number is appended to the filename. Frame padding The number of digits in frame number extensions. For example, if Frame/Animation ext is set to name.ext, and Frame padding is 3, Maya names rendered image files name.001, name.002, and so on. The default value is 1. Frame Buffer Naming

Use this field in conjunction with the multi-render passes feature. This attribute becomes active when you select the OpenEXR file format, and when your scene contains one or more render passes. Select the Automatic option to name each pass using the :. tokens, or, choose Custom to select the render tokens of your choice. Your framebuffer name must be less than or equal to 31 characters in length. Otherwise, the framebuffer name is truncated. See Image format on page 379 for more information on the OpenEXR format. Custom Naming String

Selecting the Custom option under the Frame Buffer Naming attribute to activate this field. Use this field to select the render tokens of your choice to customize the naming of the channels in your OpenEXR file.

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Use custom extension / Extension You can use a custom file format extension for rendered image file names by turning on Use custom extension, and entering the extension in the Extension text field. This extension replaces the standard extension based on file format, such as .IFF, .GIF, and so on. Version Label You can add a version label to your render output filename. Use this attribute to customize the token in the File name prefix field in the File Output on page 377 section. You can select one of the following options: a version number (for example, 1, 2, or 3), the current date, or the current time. Right-click this attribute to add the version label you desire. The first two options available (use number: n) are automatically updated each time you insert a numeric version number. For example, if you have added version number 3, the first option automatically updates to use number: 2 and use number: 4. Alternatively, you can create your own custom version label.

Frame Range Start frame, End frame Specifies the first (Start frame) and last (End frame) frames to render. Start Frame and End Frame are only available if Frame/Animation ext is set to an option containing # (see also Set file name syntax). The default value for Start Frame is 1; the default value for End Frame is 10. By frame The increment between the frames you want to render. By frame is only available if Frame/Animation ext is set to an option containing #. The default value is 1. If you use a value less than 1, make sure the Renumber frames using on page 381 option is turned on. Otherwise, many frames will appear to be missing when they are just being overwritten. Renumber frames using Lets you change the numbering of rendered image files for an animation. The Renumber frames attributes are only available if Frame/Animation ext is set to an option with # (such as name.#.ext). If on, Maya uses the frame number extensions beginning at Start Number and increasing by By Frame for rendered image file names. Start number The frame number extension you want the first rendered image file name to have. By frame The increment between frame number extensions you want rendered image file names to have.

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Renderable Cameras

Renderable Cameras Render a scene from one or more cameras. The default is to render from one camera. If you are rendering the scene from one camera (only), select the camera from the drop-down list. By default, the perspShape camera is the renderable camera. The drop-down list is divided into sections, separated by dashes:

The first section is the camera currently selected as renderable. The second and third sections list existing cameras that you can select as renderable, for example, stereo cameras and the front and side cameras. NOTE If you select Stereo Pair from the list, both the left and right stereo cameras are rendered. The third section is the Add Renderable Camera option. If you want to add another existing camera to the list of renderable cameras, you can select Add Renderable Camera. When you select this option, a new Renderable Camera section appears. Select the additional renderable camera from which you want to render the scene from the drop-down list. If you render from more than one camera, the rendered image output from each camera is stored in a different directory by default. For example, if you are rendering from camera1 and camera2, then the rendered images are stored respectively in camera1/scene.gif and camera2/scene.gif. You can also override the default settings by using the File Name Prefix attribute. Right-click the File Name Prefix attribute and select Insert camera name . This way, all rendered images are saved to the same directory and identified with the camera name (for example, _.gif

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produces camera1_scene.gif and camera2_scene.gif). See File name prefix on page 377for more information. For each renderable camera, you can also turn on or off the Alpha or Mask channel for that camera. Alpha channel (Mask) Controls whether rendered images contain a mask channel. The default setting is on. Depth channel (Z Depth) Controls whether rendered images contain a depth channel. The default setting is off. To make a camera non-renderable, remove it from the list by clicking the button beside the camera name. You should have at least one renderable camera in the scene. The remove button does not appear if only one renderable camera is listed. Override renderable camera On any render layer, you can also override the list of renderable cameras for that layer. For example, you can set cameras 1, 3, and 5 as your renderable cameras for your master layer and then set cameras 1, 2, and 4 as renderable for layer 1. To override the settings in a layer and render the scene from a different camera, select the layer, and then, in the Render Settings window, right-click Renderable Camera beside the camera name and select Create Layer Override from the drop-down menu that appears. Renderable Camera turns red to indicate that a layer override has been incorporated.

TIP If you accidentally delete the only renderable camera in your scene, you can add a renderable camera by selecting the camera name from the drop-down menu in the Renderable Cameras section.

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Image Size The Image Size attributes control the resolution and pixel aspect ratio of rendered images. For more information about resolution, see Resolution on page 65. NOTE ■

The resolution limit for the Vector renderer is 1600x1600, with the exception of EPS and AI file formats.

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When rendering larger than 6k x 6k resolutions using the Maya Software renderer, Maya requires large amounts of memory if the saved output image is one of: tiff, Avid Softimage, Autodesk-PIX, JPEG, EPS, or Cineon. In such cases, you can render to any other Maya supported image format, and use conversion tools (such as imgcvt) to convert those images to the desired format.

Presets Select a film- or video-industry standard resolution. When you select an option from 7the Presets drop-down list, Maya automatically sets the Width, Height, Device Aspect Ratio, and Pixel Aspect Ratio. You can also add a Presets option to output to an unlisted device. Render Resolution

Width

Height

Device Aspect Ratio

Pixel Aspect Ratio

Custom

any

any

any

any

320x240

320

240

1.333

1.000

640x480

640

480

1.333

1.000

1k Square

1024

1024

1.000

1.000

2k Square

2048

2048

1.000

1.000

3k Square

3072

3072

1.000

1.000

4k Square

4096

4096

1.000

1.000

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Render Resolution

Width

Height

Device Aspect Ratio

Pixel Aspect Ratio

CCIR PAL/Quantel PAL

720

576

1.333

1.066

CCIR 601/Quantel NTSC

720

486

1.333

0.900

Full 1024

1024

768

1.333

1.000

Full 1280/Screen

1280

1024

1.333

1.066

HD 720

1280

720

1.777

1.000

HD 1080

1920

1080

1.777

1.000

NTSC 4d

646

485

1.333

1.001

PAL 768

768

576

1.333

1.000

PAL 780

780

576

1.333

0.984

Targa 486 (tga)

512

486

1.333

1.265

Targa NTSC (tga)

512

482

1.333

1.255

Targa PAL (tga)

512

576

1.333

1.500

Letter

2550

3300

0.773

1.000

Legal

2550

4200

0.67

1.000

Tabloid

5100

3300

1.545

1.000

A4

2480

3508

0.707

1.000

A3

3507

4962

0.707

1.000

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Render Resolution

Width

Height

Device Aspect Ratio

Pixel Aspect Ratio

B5

2079

2952

0.704

1.000

B4

2952

4170

0.708

1.000

B3

4170

5907

0.706

1.000

2” x 3”

600

900

0.667

1.000

4” x 6”

1200

1800

0.667

1.000

5” x 7”

1500

2100

0.714

1.000

8” x 10”

2400

3000

0.800

1.000

Maintain width/height ratio Turn on this setting when you want to scale the image size proportionally in width and height. When you enter a value for either Width or Height, the other value is automatically calculated. Maintain ratio Specifies the type of rendering resolution ratio you want to use, Pixel aspect or Device aspect. The Pixel aspect ratio is the number of pixels in width to height, that compose the image. Most display devices (for example, a computer monitor) have square pixels, and their Pixel aspect ratio is 1. Some devices, however, have non-square pixels (for example, NTSC video has a Pixel aspect ratio of 0.9). The Device aspect ratio is the number of units wide by the number of units high of your display. A 4:3 (1.33) display produces an image that is more square, and a 16:9 (1.78) ratio produces an image that is more panoramic in shape. Width Specifies the width of the image in the unit specified in the Size units setting. Height Specifies the height of the image in the unit specified in the Size units setting. Size units Sets the unit that you want to specify the image size in. Select from pixels, inches, cm (centimeter), mm (millimeter), points and picas.

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Resolution Specifies the resolution of the image in the unit specified in the Resolution Units setting. TIFF, IFF and JPEG formats are able to store this information, so that it is maintained when the image is opened in a third party application such as Adobe® Photoshop®. Resolution units Sets the unit that you want to specify the image resolution. Select from pixels/inch or pixels/cm (centimeter). Device aspect ratio The aspect ratio of the display device on which you view the rendered image. The device aspect ratio represents the image aspect ratio multiplied by the pixel aspect ratio. Pixel aspect ratio The aspect ratio of the individual pixels of the display device on which you are viewing the rendered image. For more information about the pixel aspect ratio, see Pixel aspect ratio on page 65.

Render Options Enable Default Light Not available for Vector Rendering. Turn the default lighting on or off during rendering. For more information about Maya’s default lighting, see Default lighting in Maya in the Lighting guide. Pre render frame MEL, Post render frame MEL A MEL command or script to run before rendering each frame (Pre render frame MEL), or after rendering each frame (Post render frame MEL). For more information Pre render frame MEL scripts and Post render frame MEL scripts, see Pre Render MEL and Post Render MEL scripts on page 68. NOTE ■

If you need to use multiple sets of quotations in the pre frame MEL or post frame MEL fields in render settings, be sure to use \" for every quotation mark except the first and last. print("Time to render my Maya scene, called\"bingo.mb\"");

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Do not enter the .mel extension when entering the name of the script. You get an error message similar to the following:Error: Cannot link to "name.mel". Check number and types of arguments expected on procedure definition.

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Render Settings: Maya Software tab For information on the render settings, see Render Settings window on page 376.

Anti-aliasing Quality Controls how Maya anti-aliases objects during rendering. For more information about anti-aliasing and image quality, see Anti-aliasing and flicker on page 154.

Quality Select a preset anti-aliasing quality from the drop-down list. When you select a preset, Maya automatically sets all Anti-aliasing Quality attributes. The default setting is Custom. Custom When you change anti-aliasing attributes that do not match any of preset attribute values, Maya automatically sets Presets to Custom. Preview quality When test rendering scenes (fastest). Intermediate quality When test rendering scenes to produce slightly better quality than preview quality. Production quality When testing or final rendering scenes that do not contain 3D motion blur or low-contrast scenes. Contrast sensitive production When testing or final rendering high-contrast scenes (such as when you raytrace a scene. Also useful for anti-aliasing noisy bump maps). 3D motion blur production When testing or final rendering scenes that contain 3D motion blur.

Edge anti-aliasing Controls how the edges of objects are anti-aliased during rendering. Select a quality setting from the drop-down list. The lower the quality, the more jagged the object’s edges appear, but the faster the render; the higher the quality, the smoother the object’s edges appear, but the render is slower. When you select an Edge anti-aliasing quality from the drop-down list, Maya automatically sets all Anti-aliasing Quality attributes (in the subsections).

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Low quality Fastest anti-aliasing setting. For each rendered pixel, two points are analyzed and used to determine which part of the object is visible, producing low quality edge anti-aliasing. Medium quality For each rendered pixel, eight points are analyzed and used to determine which part of the object is visible, producing medium quality edge anti-aliasing. Although a little slower, produces moderately good edge anti-aliasing. This can be good for test rendering moderately complex scenes. High quality For each rendered pixel, 32 points are analyzed and used to determine which part of the object is visible, producing high quality edge anti-aliasing. Can be used for testing as well as production rendering. Highest quality Highest quality anti-aliasing computes the image in two passes, looking for color contrasts within pixels and in surrounding pixels, such as highlights. The first pass is the High quality computation—the second pass looks for color contrast in the results of the first pass. In the regions where color contrast is high (for example, in regions containing highlights), more shading samples are taken. Improves on the High quality and is excellent for picking up highlights that may be missed by a single pass (when you use High quality).

Number of Samples Shading The number of shading samples for all surfaces. This option works in conjunction with Shading Samples, an attribute available from the Render Stats section of a surface’s Attribute Editor. Shading Samples sets the number of times Maya shades in a pixel. For details, see Render Stats and Shading Samples. Max Shading Not available if you choose Preview Quality from the Presets menu as the Anti-aliasing Quality. The maximum number of shading samples for all surfaces. This option works in conjunction with Max Shading Samples, an attribute available from the Render Stats section of a surface’s Attribute Editor. Max Shading Samples sets the maximum number of times a pixel is shaded during the second pass of a Highest Quality render. The higher the number, the longer the rendering takes, but the more accurate the resulting image. 3D blur visib. The number of visibility samples Maya takes to accurately compute a moving object’s visibility as it passes over another object

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TIP ■

3D Blur Visib and Max 3D Blur Visib, are associated with Max Visib Samples available in the 3D Motion Blur section of a surface’s Attribute Editor. For details, see 3D Motion Blur on page 514.

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3D Blur Visib and Max 3D Blur Visib.are only available when you turn 3D Motion Blur on in the Motion Blur section of the Render Settings window on page 376.

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Max Visib Samples is the maximum number of times a pixel is sampled for visibility when Motion Blur is turned on.

Max 3D blur visib. The maximum number of times a pixel is sampled for visibility when Motion Blur is turned on. Particles The number of shading samples for particles. This option works with Shading Samples, an attribute available from the Render Stats section of a surface’s Attribute Editor. Shading samples sets the number of times Maya shades each fragment in a pixel. See Render Stats and Shading Samples for more details.

Multi-pixel Filtering Multipixel filtering blurs or softens the entire rendered image to help eliminate aliasing or jagged edges in rendered images, or roping or flicking in rendered animations. These options are only available when the “Edge Anti-aliasing” quality is set to either High Quality or Highest Quality. Use multi pixel filter If on, Maya process, filters, or softens the entire rendered image by interpolating each pixel in the rendered image with its neighboring pixels, based on the Pixel filter type and the Pixel filter width X, Y settings. NOTE If you are rendering fields, Maya does not filter rendered images, even if Use multi pixel filter is on. Pixel filter type Controls how much the rendered image is blurred or softened when Use multi pixel filter is on. There are five preset filters to choose from—Box filter (very soft), Triangle filter (soft), Gaussian filter (only slightly soft), Quadratic B-Spline filter (the filter used in Maya 1.0) and Plug-in filter. The default is Triangle filter. To use a custom filter, select Plug-in Filter.

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To create a plug-in filter, Create and load a plug-in multipixel filter on page 94. Pixel filter width X, Y Controls the filter width used to interpolate each pixel in the rendered image when Use multi pixel filter is on. If larger than 1, it uses information from neighboring pixels. The larger the value, the more the image is blurred. The valid range is 1 to 3. The default value is 2.2. TIP The Pixel filter width X and Pixel filter width Y values do not need to be the same; however, to blur the rendered image equally in both directions, these values should be the same.

Contrast Threshold Determines adaptive sampling. Controls the number of shading samples taken during the second pass computation when Edge anti-aliasing is set to Highest quality. Red, Green, Blue Each color channel is evaluated and if the contrast of the neighboring pixel exceeds the threshold, more samples are taken. The valid range is 0 to 1. The default values are 0.4 (Red), 0.3 (Green), and 0.6 (Blue). If Presets is set to Contrast Sensitive Production, the default values are 0.2 (Red), 0.15 (Green), and 0.3 (Blue). TIP ■

Reducing RGB values sometimes bring out interesting features in rendered images (for example, small highlights or shadow boundaries), but can also increase rendering times.

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In relatively colorless images that exhibit shading aliasing (for example, gray shadows that look ropy), try setting Red to 0.3, Green to 0.2, and Blue to 0.5.

Coverage Only available when 3D motion Blur is on. Controls number of Visibility Samples taken during 3D motion blur computation. If visibility variation exceeds the threshold, more samples are taken. For example, reducing this number helps the renderer detect the change of visible objects in a pixel (but also increases rendering times). The valid range is 0 to 1. The default value is 0.125.

Field Options Use these options to control how Maya renders images as fields.

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To find out more about frames and fields, see Frames vs. Fields on page 65 and Specify frame or field rendering on page 91.

Render Controls whether Maya renders images as frames or fields, which is useful for output to video. NOTE You can use interlace (Linux), or fieldAssembler (Windows), or a compositing or NLE application (Mac OS X) to interlace the fields. See interlace in the Rendering Utilities guide for details on interlacing. Frames Renders regular frames. Both fields, interlaced Renders both odd and even fields (for video) and automatically interlaces the results into a full frame. Both fields, separate Same as above, except no interlacing occurs. The result is a sequence of odd and even field images. Odd fields Renders odd fields only. Even fields Renders even fields only. Field dominance Controls whether Maya renders Odd fields at time x and even fields at time x+0.5, or Even fields at time x and odd fields at time x+0.5. NOTE If the Render attribute under Field Options is set to Frames, the Field dominance options are not available. If set to Both fields, interlaced, Maya sets the appropriate field dominance based on the format standard (NTSC or PAL).

Zeroth scanline (For advanced users only.) Controls whether the first line of the first field Maya renders is at the top of the image or at the bottom. NOTE If the Render attribute under Field Options is set to Frames or Both Fields, Interlaced, the Zeroth Scanline options are not available. Maya chooses the appropriate setting based on the format standard, NTSC or PAL. At top/At bottom At Top is on by default. If you encounter problems in an animation where field order appears wrong (for example, objects vibrate up and down), change the Zeroth Scanline setting and render the animation again. If this does not solve the problem, or if objects in the animation vibrate left to right, try different combinations of Field Dominance and Zeroth Scanline, until the problem is solved.

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Field extension Select one of the following options: No field extension The attributes in this section do not take effect if the fields are interlaced automatically. No extension is added to odd and even field file names. Default field extension (o and e) The attributes in this section do not take effect if the fields are interlaced automatically. Maya saves the two field image files by adding an e (for even fields) and an o (for odd fields) onto the frame number extension or file name. For example, name.001e.iff and name.001o.iff. This is the default setting. Custom extension The attributes in this section do not take effect if the fields are interlaced automatically. Set on to specify custom extensions to add to odd and even field file names. For example, if you type x, the result is name.001x.iff. Odd field The extension to add to odd field file names. Even field The extension to add to even field file names.

Raytracing Quality Controls whether a scene is raytraced during rendering, and controls the quality of raytraced images. When you change these global settings, the associated material attribute values also change. The resulting value is the smaller value of the two attribute settings. For more information about raytracing, see Depth map and raytraced shadows in the Lighting guide. Raytracing If on, Maya raytraces the scene during rendering. Raytracing can produce accurate reflections, refractions, and shadows (this can increase rendering times considerably, so try to use sparingly). Reflections The maximum number of times a light ray can be reflected. The valid range is 0 to 10. The default value is 1. For details, see Reflection Limit. Refractions The maximum number of times a light ray can be refracted. The valid range is 0 to 10. The default value is 6. For details, see Refraction Limit. TIP If refractions turn black, make sure the refraction limits is set to a high enough value and that Visible in Refractions is turned on for the object in the Attribute Spreadsheet (Window > General Editors > Attribute Spread Sheet) and the Rendering Flags window (Window > Rendering Editors > Rendering Flags).

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Shadows The maximum number of times a light ray can be reflected and, or refracted and still cause an object to cast a shadow. A value of 0 turns off shadows. For example, if the Shadows value is 2, only light rays that have been reflected and, or refracted once cause an object to cast a shadow. The valid range is 0 to 10. The default value is 2. Bias If the scene contains 3D motion blurred objects and raytraced shadows, you may notice dark areas or incorrect shadows on the motion-blurred objects. To solve this problem, set the Bias value between 0.05 and 0.1. If the scene does not contain 3D motion blurred objects or raytraced shadows, leave the Bias value as 0. The valid range is 0 to 1. The default value is 0.

Motion Blur When you render an animation, motion blur gives the effect of movement by blurring objects in the scene. You can turn Motion blur on or off for objects. Maya uses the relationship between the Shutter Angle and Motion blur attributes to determine how much blur is applied to an object. For information about how a camera’s shutter speed/angle affect motion blur, see Motion blur on page 16. Motion Blur If on, the 3D Motion blur type is enabled as well as Blur by frame. This means that moving objects appear blurred. If off, moving objects appear sharp. Motion blur is off by default.

Motion blur type The method Maya uses to motion blur objects. 2D 2D motion blur is a post-process; Maya blurs each object in the image after rendering the entire image based on the object’s motion vector (its speed and direction). 3D 3D motion blur is similar to real-world motion blur, but takes longer to render than 2D motion blur. The default setting is 3D. Blur by frame The amount moving objects are blurred. The higher the value the more motion blur is applied to objects. For example, if you motion blur by 1 frame, blur is calculated based on the motion of objects from one frame to the next; if you motion blur by 4 frames, blur is calculated based on the motion of objects every four frame lengths, during which time much motion is detected, and therefore much blur is applied. The default value is 1. The amount that moving objects are blurred is also based on the Shutter Angle of the camera. The length of the frame is determined by: (Shutter Angle/360) * Blur by Frame

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The Shutter Angle can be modified in the Special Effects section of the Camera’s Attribute Editor. Blur length Scales the amount that moving objects are blurred.The valid range is 0 to infinity. The default value is 1. Use Shutter Open/Close Enable this option to customize the Shutter Open and Shutter Close values. Shutter Open /Shutter Close Shuttter open and close values. Default values are -0.5 for Shutter Open and 0.5 for Shutter Close. The Use Shutter Open/Close, Shutter Open and Shutter Close attributes can also be set using the renderGlobals node. The shutter duration cannot be negative. If a user alters the values in the Render Settings window such that the shutter duration is negative, the values will be altered to suit a positive duration. If a negative shutter duration is set on the renderGlobals node, the software renderer will disregard these values and render as if the Shutter Open / Shutter Close values have never been set. This feature is an addition to the motion blur feature. If both Motion Blur and Use Shutter Open/Close are disabled, then motion blur is not used in the render. If Motion Blur is enabled but Use Shutter Open/Close is disabled, then Maya renders with motion blur and with the shutter opening and closing at their default values, which is [-0.5, 0.5]. If both Motion Blur and Use Shutter Open/Close are enabled, then Maya will open and close the shutter of the camera at the times you specified. Blur sharpness The sharpness of motion blurred objects. The larger the Blur sharpness, the more spread out the blur. The valid range is 0 to infinity. The default value is 1.

Smooth Select one of the following options: Alpha/Color Sometimes, anti-aliasing performed by the Smooth Value attribute can fail and produce artifacts corresponding to edges in the alpha channel of the unblurred image. For example, when bright opaque objects pass in front of dark light fog. Turning on Alpha or Color in such cases eliminates artifacts by additionally blurring the objects. Smooth value The amount Maya blurs motion blur edges. The larger the value, the more the motion blur is anti-aliased.The valid range is 0 to infinity. The default value is 2.

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TIP ■

Increasing the Smooth value may also blur the edges of static objects, so if you do not want this effect, set Smooth value to 0.

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You may not want extra blurring all the time, so only use this attribute when necessary. You can also try setting Smooth value to 0, which results in less anti-aliasing, but that may only be acceptable in some situations.

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For objects shaded with the Ramp Shader, 2D motion blur provides better results than 3D motion blur (artifacting), but the Smooth attribute must be set to Color, not Alpha.

Keep motion vectors If on, Maya saves the motion vector information for all visible objects in the rendered image but does not blur the image. This lets you blur the rendered images using the vector data with other 2D blur software (for example blur2d). NOTE This only works for Maya IFF images. If off, Maya blurs the rendered image but does not save the motion vector information. Keep motion vectors is off by default. Use 2d blur memory limit You can specify the maximum amount of memory used by the 2D blur operation. Maya uses whatever memory is available to finish the 2D blur operation. 2D blur memory limit You can specify the maximum amount of memory the operation uses. If Motion blur is on and the Motion blur type is set to 2D, the Use 2d blur memory limit is on by default and provides a default memory limit of 200 MB. This default limit should be sufficient to eliminate most problems. However, you can specify the size of the memory cap (in MB) in the field provided.

Render Options Post Processing Environment fog Creates an environment fog node. Environment fog (a Volumetric material) is used to simulate the effect of fine particles (fog, smoke, or dust) in the air. These particles affect the appearance of the atmosphere and the appearance of objects in the atmosphere. For more information on Environment fog, see Environment Fog in the Shading guide.

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Apply fog in post Only render the fog as a post-process. When on, you can set the Post fog blur. Post fog blur When used in combination with Apply fog in post, allows environment fog effects to appear as if they are spilling over the geometry edges. Increase this value for more blur. NOTE The results of this option cannot be seen in IPR.

Camera Ignore film gate If on, Maya renders the area of the scene visible in the Resolution Gate. If off, Maya renders the area of the scene visible in the Film Gate and the region outside is rendered background color. See Camera Settings and Film Gate for information on how to viewing the film gate boundary interactively. Ignore Film Gate is on by default.

Lights and Shadows Shadow linking You can reduce the rendering time required for your scene by linking lights with surfaces so that only the specified surfaces are included in the calculation of shadows (shadow linking) or illumination (light linking) by a given light. Use the drop-down list to select one of the three choices available with this option: ■

Shadows obey shadow linking

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Shadows obey light linking

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Shadows ignore linking

The shadows in your scene can obey only one of light linking or shadow linking and not both. Therefore, you must decide whether to incorporate light linking or shadow linking in your scene and make your selection from the drop-down list accordingly. You can also render part of your scene using the default settings (instead of obeying the links that you have created). Select Shadows ignore linking so that all links that you have established or broken using shadow linking or light linking are ignored. The default is set to Shadows obey light linking. See Shadow linking for more information regarding shadow linking. See Light linking for more information regarding light linking.

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Enable depth maps If on, Maya renders all depth map shadows for all lights which have depth map shadows turned on. If off, Maya does not render depth map shadows. Enable depth maps is on by default.

Color/Compositing Gamma correction Color corrects rendered images according to the following formulas. The default value is 1 (no color correction).

NOTE The behavior of the Gamma correction attribute for the Maya software renderer is the reverse of that of the Gamma on page 429 attribute for the mental ray renderer. For the Maya Software renderer, a higher gamma value lightens the mid-tones of the image. For the mental ray renderer, a higher gamma value darkens the mid-tones of the image. Clip final shaded Color If on, all color values in the rendered image are kept between 0 and 1. This ensures that no parts of the image (for example, foreground objects) are overexposed. If off, color values in the rendered image may be greater than 1. Clip final shaded color is on by default. Jitter final color If on, the image color is jittered to reduce banding. Premultiply If this option is on (default), premultiplication takes place (see Premultiplied images on page 78). If this option is off, the premultiply threshold option is enabled. If off, Maya renders objects so that they are not anti-aliased against the background. For example, a pixel on the edge of an object is not mixed with the background color. (In TIFF terms, Maya generates unassociated alpha.) If on, Maya anti-aliases objects against the background. Premultiply is on by default. TIP If you are rendering images for film or video, turn Premultiply off. If you are rendering images for a video game, turn Premultiply on.

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Premultiply threshold If this option is enabled (when the default premultiply is turned off), per-pixel color values are output only if the pixel’s alpha channel value is above the threshold set here. Controls the amount of edge anti-aliasing in a matte if Premultiply is on. If you are rendering images for use in a video game, and you are using 8 or 16 bit color, set Premultiply threshold to 1 for smooth matte edges, with no jagged edges. The default value is 0.

Memory and Performance Options The Memory and Performance Options attributes help you optimize rendering to make scenes render faster. For more information on render speed and image quality, see The speed/quality tradeoff on page 153.

Tessellation Helps manage how Maya handles tessellation information for surfaces. Use file cache Enables the storing of geometry information into a “cache” file in the directory specified by the system’s TEMP (Windows and Mac OS X) or TMPDIR (Linux) environment variable to reduce the amount of memory used to store geometric data. Turning on this option lets the renderer perform its own swapping. In the Maya.env file, enter TEMP = defaultPath, where defaultPath is the pathname of the new temporary directory. ■

(Linux). If TMPDIR is set, Maya uses that directory unless it has write permission problems, in which case Maya defaults to /usr/tmp. If still not able to write to /usr/tmp, a warning message appears.

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(Windows). If TEMP is set, it uses that directory provided it’s writable. If it’s not writable, a warning message appears.

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(Mac OS X). If TEMP is set, Maya checks for write permissions, and the directory if not writable, it defaults to using the Documents/temp directory under your Home directory. If not able to write to Documents/temp, a warning message appears.

If the above still fails to find a temporary directory, a final attempt is made to set the current directory you are working in as the temporary directory.

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NOTE Use file cache helps to prevent maxing out memory bandwidth and disk space when you are rendering a heavy scene on a multi-processor machine. Before rendering very large, type: Linux: setenv TMPDIR NAMEOFDIR

Windows: SET TEMP=NAMEOFDIR

where NAMEOFDIR is the location of a partition with a lot disk space. Optimize instances If on and the scene contains several identical surfaces (for example, instanced surfaces or identical surfaces created independently), Maya tessellates only one of them, saving time and disk space. Optimize instances is on by default. Reuse tessellations If on, Maya temporarily saves tessellation information to disk for each frame. This is useful if a scene contains depth map shadows. For example, Maya tessellates surfaces when generating the depth map for a light (and saves the tessellation information to disk), and then reuses the tessellation information when generating depth maps for other lights and when rendering the frame. (Maya removes the tessellation information from disk, and recalculates it for the next frame.) Reuse tessellations is on by default. NOTE Reuse Tessellations is an I/O-bound process that can max out the bandwidth when running multiple render jobs on the same machine. Reuse Tessellations is useful when running up to four jobs on a multi-processor machine. You can try turning off Render Settings > Use file cache. Use displacement bounding box Rendering can take a long time when you use displacement mapping because before rendering tiles, Maya tessellates all the displacement-mapped surfaces and calculates their bounding boxes. When you turn on Use displacement bounding box, Maya calculates the bounding box scale that you define for all displacement-mapped surfaces. This makes rendering faster. When off, Maya pre-tessellates all the displacement-mapped objects before rendering. See Bounding Box Scale for details.

Ray Tracing Helps control raytracing. For information on raytracing attributes, see Raytracing Quality.

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For more information on raytracing, see Depth map and raytraced shadows in the Lighting guide. Recursion depth Determines how many levels of recursion to use for the raytracing voxel data structure of the rendering. For very complex scenes, this should be set to 2 or 3. For less complicated scenes, a setting of 1 should be fine. The default is 2. Leaf primitives Determines the maximum number of triangles to allow in a voxel before going to the next recursive level. The default is 200. Subdivision power Represents the power that the number of triangles in a voxel is raised to in order to calculate how many voxels should be created when recursion is required. The default is 0.2500, which should be appropriate for most scenes. For extremely complex scenes or scenes with complex parts, this value can be increased slightly.

Multi Processing Multi-threaded interactive rendering is available for the Render View. It provides the same kind of performance gain for the batch renderer. The number of CPUs to use for interactive rendering and IPR are set separately. Maya saves the value you set with the scene. For more information, see Network render with Maya software on page 171. Use all available CPUs By default, all available CPUs are used. If off, the slider below the option is enabled. Num. CPUs to use The slider can be dragged from values 1 to 8, but larger values up to 256 can be entered if needed. Entering a value of 0 or turning the option on enables all CPUs for interactive rendering. NOTE ■

If you want a Multi-Processor batch render, set the number of processors to use in the Batch Render window, or use the -n flag (for Maya software rendering), for command line rendering.

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If IPR is in use, the number of CPUs cannot be changed until the current IPR session is closed. The following warning appears:// Warning: IPR will need to be closed before this change in CPUs will take effect. //

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IPR Options These attributes determine which shading elements are saved to disk when you perform an IPR render. This can save time and disk space. For more information on IPR, see Interactive Photorealistic Rendering (IPR) on page 47. Render shading, lighting and glow Determines whether to process shading, lighting and glow characteristics of the next IPR Render. Render shadow maps Depth map shadows are included in IPR renders. Turn on to show depth map shadows in the scene and be able to update them when tuning. Because generating a depth map is a time consuming and processor-intensive operation (like a full rendering from the light’s point of view), IPR does not automatically generate depth maps when you adjust attributes. NOTE ■

Attributes in the first part of the Depth Map Shadow Attributes section of a light’s Attribute Editor affect how the depth map is created; you must select IPR > Update Shadow Maps to see the effect of changes you make to these attributes.

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Attributes in the second part of the Depth Map Shadow Attributes section of a light’s Attribute Editor affect how the depth map is used; you can adjust these attributes, and see the results immediately in your IPR session.

Render 2D motion blur Turn on to adjust 2D motion blur for the next IPR Render. Only 2D motion blur is tunable.

Paint Effects Rendering Options For more information about Paint Effects, see What is Painting in Maya? in the Paint Effects and 3D Paint Tool guide. The following describes only render options for the Paint Tool. Enable stroke rendering Turn on to render the Paint Effects strokes in the scene. If off, the scene renders without strokes. This option is turned on by default. Oversample Renders the Paint Effects at double resolution for better anti-aliasing.

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Oversample post filter Applies a weighted filter to the oversampled image for better smoothing. NOTE The Oversample and Oversample post filter options are particularly useful when rendering Paint Effects fur or hair. Also the new Mesh Brush Type requires oversample be used to anti-alias the tube edges if you don’t convert the Paint Effects to Polygons. Only render strokes Turn on to render only the Paint Effects strokes in the scene. You may want to render the strokes separately from the rest of the scene, then composite the strokes with the scene. See For more information about Paint Effects, see What is Painting in Maya? in the Paint Effects and 3D Paint Tool for details. Read this depth file If compositing the rendered scene with rendered Paint Effects strokes, type the location and name of the depth file for the rendered scene. Use the absolute path name (for example, /h/username/rainyday.iff (Linux), or c:\username\rainyday.iff (Windows), or /username/rainyday.iff (Mac OS X)). NOTE When you render strokes only, you must also specify an .IFF file in the Read this depth file field (see next). The file can be empty. It does not have to have depth. If rendering an animation and have an animated input file, place the # character where the frame number is in the source input files. For example, for files foo1.iff, foo2.iff, and so on, enter foo#.iff. For files foo1, foo2, and so on, enter foo#. When you render, the # character is replaced with the current frame number. For more information about Paint Effects strokes, see What is Painting in Maya? in the Paint Effects and 3D Paint Tool guide. NOTE It is best to supply a depth file and allow Maya Paint Effects to do the compositing rather than attempt to composite Paint Effects as a post process using a compositor. Maya Paint Effects uses a multi-layer depth and RGB buffers to perform the compositing with the scene and can achieve a much better composite than a post process compositor can achieve. Also, if you do not supply a depth file (an .IFF file with depth information), Paint Effects strokes that are behind objects in your scene are rendered. Maya does not overwrite your existing images supplied as a depth file—the output is named as shown at the top of the Render Settings window on page 376.

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Render Settings: mental ray tabs

For information on other render settings, see Render Settings window on page 376. The mental ray tabs consists of five tabs: Passes tab on page 404, Features tab on page 406, Quality tab on page 415, Indirect Lighting tab on page 432, and Options tab on page 444.

Passes tab

Use this tab to do the following: ■

create, edit and delete a render pass

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create, edit and delete a render pass set. A render pass set is a group of render passes.

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create, edit and delete a render pass contribution map

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manage the list of render passes for the current layer

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manage the list of render passes for each of the pass contribution maps in your current layer

NOTE See Multi-render passes on page 187 for more information regarding render passes.

Render Passes Use the and buttons to add a new render pass or a new render pass set to the current layer.

New Pass Click to open the Create Render Passes window. See Create Render Passes window on page 470 for more information.

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New Set

Click to create a new render pass set.

Edit Click to open the Attribute Editor for the selected render pass or render pass set. Alternatively, you can double-click a pass or pass set in the Scene Passes, Associated Passes, or Passes Used by Contribution Map sections to open its Attribute Editor.

Delete

Deletes the selected render pass(es).

Pass Set Relationship Editor Click to open the Relationship Editor. You can use the Relationship Editor to manage the membership of each pass set. Scene Passes Lists all the render passes and render pass sets that are available to be assigned to the current layer. After a render pass or render pass set is assigned to the render layer, it no longer belongs to the Scene Passes list. In other words, this list shows only passes that not assigned to the current render layer. Associated Passes Use the left and right arrow buttons to associate and de-associate render passes from the current active render layer. NOTE You can also right-click a render pass/pass set to set it as renderable; or, create an override for the pass/pass to make it renderable. Associated Pass Contribution Map Use this section to manage the render passes for each pass contribution map. Select the pass contribution map that you want to manage from the drop-down list. See Render Layer Editor on page 367 and Render pass contribution maps on page 190for more information regarding pass contribution maps.

New pass contribution map contribution map.

Click to create a new render pass

Edit pass contribution map Click to open the Attribute Editor for the selected pass contribution map.

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Delete pass contribution map map.

Delete the selected pass contribution

Passes Used by Contribution Map Use the up and down arrow buttons to manage the list of passes for the current pass contribution map. NOTE Any pass in the Associated Passes section that is not affiliated with a pass contribution map is generated for the layer.

Toxik Toxik pre-compositing template for Use this section for Toxik pre-compositing. Each render layer can have an optional toxik pre-compositing template file associated with it. This pre-compositing file (enter a file path and file name) is used when Render > Export Pre-Compositing is selected. If this field is left empty, a Toxik composite is constructed without a template and provides only the passes that have been rendered. The user must then wire the render passes to create a composite. A default template is provided which covers all render passes available in Maya. See Exporting the multi-render passes for compositing in Toxik on page 233for more information.

Features tab Render Mode

Select one of the following options: Normal Render all features set in the Render Settings window. Final Gathering Only Performs final gather computation only. Use this mode to create or update an final gather map file associated with the render layer. It can also be used to create a final gather map file for each frame or for specific frames. Once the final gather map has been created, the user can switch back to Normal mode, and reuse the pre-computed final gather map files for final gather rendering. Shadow Map Only Each light can, optionally, enable shadow maps (normal or detailed). During a normal render, shadow maps are computed "on demand" for the portion of the shadow map required. The Shadow Map Only mode is designed to pre-compute shadow map files without triggering any other rendering process. This can greatly help rendering speed since the pre-computed shadow maps can be used by several other machines on the

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render farm. A shadow map is dependent on light position and object position; if any of these elements are to be moved, the shadow map is most likely to require a recomputation. This mode does not detect which lights needs to be updated, but instead systematically re-computes all lights with shadow map statements. Light Map Only Light maps are used for two purposes: custom baking (requires a special shading network for each object) and for subsurface scattering. The Light Map Only mode is most useful for forcing all lights maps to be computed without triggering any other rendering process. By doing so, this mode allows you to precompute light map based shading such as sub-surface scattering. The user can precompute all light maps and subsurface scattering maps as pre-render passes. Rendering on the farm is therefore much more efficient, since the sub-surface scattering maps have already been computed.

Primary Renderer Select one of the following options: Scanline Scanline rendering is faster for smaller scenes. When rendering large and complex scenes, use the rasterizer or raytracer as the primary renderer instead. Scanline requires extra memory requirements during rendering which raytracer and rasterizer do not. Rasterizer (Rapid Motion) A substantially faster motion blur algorithm alternative. Formerly named Rapid Scanline. The rasterizer offers a much greater control over rendering quality without impacting rendering times. For example, if you render using scanline rendering with the Min Sample Level and Max Sample Level set to 0 and 1, then, if there are artifacts due to bad aliasing, you would increase the min and max sample level to 1 and 2. Doing so quadruples the number of samples in each pixel. The rasterizer has greater control over quality. It increases quality without systematically quadrupling rendering time; instead rendering time increases linearly. Raytracing Turn off the scanline renderer and force mental ray to use raytracing for the primary rays. NOTE ■

For small or static scenes, scenes with final gather, or scenes without much depth complexity, scanline rendering is a faster way of rendering. However, for large scenes, scenes with a lot of hair, or scenes with a lot of motion blur, you should use rasterizer rendering instead.

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Contour rendering does not currently work with the rasterizer.

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Default quality settings for the Rasterizer are typically higher than those of the default scanline. For example, the default value of 0 for Visibility Samples is equivalent to a Min/Max Sample Level of 1 for scanline.

Secondary Effects Select one of the following options: Raytracing Turns raytracing on or off. Enables reflections and refractions. Global Illumination Turns global illumination on or off. Caustics Turns caustics on or off. Importons

Turns importons on or off. Importons can be used when raytracing is enabled and in combination with global illumination, caustics and irradiance particles. See Importons on page 437for more information regarding importons. Final Gathering Turns final gather on or off. Irradiance Particles

Turns irradiance particles on or off. Enabling irradiance particles also enables importons by default. If final gathering is enabled, then irradiance particles is disabled. Ambient Occlusion

Turns ambient occlusion on or off. NOTE You must enable Ambient Occlusion if you are creating an ambient occlusion pass. See Multi-render passes on page 187 for more information. Shadows Turns shadows on or off.

Motion Blur Select one of the following options:

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Off Turns motion blur off. No Deformation No Deformation only considers the position of objects at the Shutter beginning and end point (open and close points). It performs object-based interpolation and is fast but limited. Full Full is slower to render, but gives true (that is, exact) motion blur results. Each deformed surface is being translated "per vertex", instead of per object transform.

Extra Features Faces Determines whether to render double-sided or single-sided for the entire scene. Front Only front-facing (that is, the side whose normal vectors face away from) are rendered. Back Only back-facing are rendered. Both Works especially well if volume effects are used. Turn these options off, to globally disable the following features in your scene:

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Geometry Shaders

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Light Maps

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Lens Shaders

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Displacement Shaders

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Displacement Pre-sample Enables pre-computation of displacement maps to find optimal bounding boxes.

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Volume Shaders

Volume Samples This setting specifies the default value for the number of volume samples for any volume effects in Maya shaders. The default value is 1. NOTE When Auto Volume is turned on, Raytracing is automatically enabled and greyed out.

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Auto Volume If enabled, mental ray manages volume levels and the volume stack automatically.

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Output Shaders

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Photon Auto Volume

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Merge Surfaces

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Render Fur/Hair

Contours The following attributes control the location and characteristics of contour line rendering. Enable Contour Rendering Turn on or off (default) contour rendering. Hide Source When turned on, only the contour is visible (that is, the object that causes the contour invisible). Flood Color When Hide Source is turned on, this is the conlour used to flood or fill the entire frame as the background color before rendering the contour. In other words, this is the color onto which the contours caused by Hide Source are drawn. Over-Sample Improves the quality by processing at N times larger than sampling down to the correct size. If this value is set to 2, the contours are processed at twice the resolution, so the quality (anti-aliasing mostly) will be approximately twice as good. Filter Type The filter type used when downsampling contours to image resolution. Filter Support The filter support as (fractional) number of pixels.

Draw By Property Difference Options in the detection section let you define the locations at which mental ray for Maya detects and draws contour lines. Around silhouette (coverage) Draw contour lines based on pixel coverage (where rendering samples detect objects are present) based on a pixel being covered by the object.

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Around all poly faces Draw contour lines around each poly face on an object.

Around coplanar faces Draw contour lines between different normals.

Between different instances Draw contour lines between different instances.

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Between different materials Draw contour lines between primitives with different materials.

Between different labels Draw contour lines between different labels (these are not the same as character labels). Around render tesselation Draw contour lines between different primitives. (Enabling this in effect draws tessellations.)

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Front vs. back face contours Draw contour lines between, if the sign of the dot product of the normal vector and the view vector differs from one sample to the other.

Draw By Sample Contrast Enable Color Contrast Turns on or off (default) the color contrast setting. Color Contrast Draw contour lines between pixels that have a color difference that is larger than the set value.

Enable Depth Contrast Turns on or off (default) the depth contrast setting. Depth Contrast Draw contour lines between pixels whose depth difference (in camera space) is larger than the set value.

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Enable Distance Contrast Turns on or off (default) the distance contrast setting. Distance Contrast Draw contour lines between pixels whose distance is larger than the set value.

Enable Normal Contrast Turns on or off (default) the normal contrast setting. Normal Contrast Draw contour lines between pixels whose normal difference is larger than the set value. (Normal difference is measured in degrees.)

Enable UV Contours Turns on or off (default) the UV contour setting.

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UV Contours Draws contour at every Uth and Vth isoline of the primary UV space.

Custom Shaders You can connect mental ray for Maya base contour store and contrast shaders here. Any shaders connected here override the integrated contour rendering feature.

Quality tab Quality Presets When you select a Preset here, settings in the applicable sections in the mental ray tabs are automatically set (for example, Preview: Global Illumination turns on Global Illumination and sets other defaults in the Caustics and Global Illumination section). Use these settings as a starting point for rendering your image at a given quality and with a certain effect. Custom Lets you specify the mental ray for Maya quality settings independently. Draft Gives you a relatively good indication as to what scene will look like while taking the least amount of processing time. Draft: Motion Blur Gives you a relatively good indication as to what scene will look like, with motion blur, while taking the least amount of processing time. Draft: Rapid Motion Gives you a relatively good indication as to what the scene will look like, when using Rasterizer (Rapid Motion), while taking the least amount of processing time.

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Preview Slightly better than Draft, takes a little more processing time, but achieves a good balance between quality and time. Preview: Caustics Slightly better than draft (but includes caustics), takes a little more processing time, but achieves a good balance between quality and time. Preview: Final Gather Slightly better than draft (but includes final gather), takes a little more processing time, but achieves a good balance between quality and time. Preview: Global Illumination Slightly better than draft (but includes global illumination), takes a little more processing time, but achieves a good balance between quality and time. Preview: Motion Blur Slightly better than draft (but includes motion blur), takes a little more processing time, but achieves a good balance between quality and time. Preview: Rapid Motion Slightly better than Draft (when using Rasterizer (Rapid Motion)), takes a little more processing time, but achieves a good balance between quality and time. Production Use this when testing the final rendering or rendering the final image(s) that do not contain motion blur. Production: Motion Blur Use this when testing the final rendering or rendering the final image(s) that contain motion blur. Production: Rapid Fur Production quality results using Rasterizer (Rapid Motion) for scenes with fur. Production: Rapid Hair Production quality results using Rasterizer (Rapid Motion) for scenes with hair. Production: Rapid Motion Use this when testing the final rendering, or rendering the final image(s) when using Rasterizer (Rapid Motion). Production: Fine Trace Production quality results for scenes with raytracing. This preset turns on Scanline raytracing, and provides quick results.

Anti-Aliasing Quality Controls how mental ray for Maya anti-aliases objects during rendering. For more information about anti-aliasing and image quality, see Anti-aliasing and flicker on page 154.

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Raytrace/Scanline Quality Sampling Mode Select one of the following options: Fixed Sampling Use a fixed number of samples per pixel when processing an image. Adaptive Sampling The number of samples used per pixel varies depending on the contrast of your scene. The Max Sample Level and Min Sample Level will not differ by more than 2. Custom Sampling The number of samples used per pixel varies depending on the contrast of your scene. Custom Sampling allows you to tune the Min Sample Level and Max Sample Level independently, while retaining true adaptive sampling (unless the min and max sample level are set to the same value). Custom Sampling also allows you to set the min and max sample level to greater than two. In general, the min and max sample level should not differ by more than 3. Min Sample Level This is the guaranteed minimum number of samples per pixel used when processing an image. Based on Anti-aliasing Contrast on page 418 settings, mental ray for Maya will increase these samples as needed. You can enter a negative value for this field. Instead of super sampling, infra-sampling is performed, where 1 pixel is sampled for each N pixels, depending on your Min Sample Level. Max Sample Level This is the absolute maximum number of samples per pixel used when processing an image. Number of Samples Indicates the actual number of samples to be calculated based on the current settings. NOTE When Adaptive Sampling is selected, the Max Sample Level and Min Sample Level will not differ by more than 2. This is the recommended setting. For advanced users: if you wish to override the default recommended setting for per object sampling, choose Custom Sampling. Diagnose Samples Shows how spatial supersamples were placed in the rendered image, by producing a grayscale image signifying sample density. This is useful when tuning the level and the contrast threshold for spatial supersampling. More diagnostic attributes are available in the Diagnostics section under the Options tab on page 444.

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Anti-aliasing Contrast Use the slider to set your contrast threshold. Lowering this value increases sampling (up to the Max Sample Level on page 417), which results in higher quality but longer processing time. Depending on the actual contrast of the image, you may not be able to get better results (that is, results are limited by the amount of contrast). NOTE This attribute was previously named Contrast Threshold, with one slider for an RGB value and one slider for an alpha value. The single slider sets RGBA to the same value under the hood. If you want different values for RGBA, you can do this through scripting or through the miDefaultOptions node.

Rasterizer Quality Visibility Samples This value indicates the number of samples used for anti-aliasing. The default value is 0. Shading Quality This value indicates the number of shading samples per image pixel. The default value is 1.0 and the minimum value is 0.001.

Multi-Pixel Filtering Filter This is processing performed on the results of the sampling to blend pixels into a coherent entity. Black and white = noisy. Filtering looks at neighboring info and unifies the two. It is better to apply filtering in the renderer, since there is more information (samples) to work with and filtering can offer better control when applied to samples than as a post-process and applied to pixels. Box (default) The fastest way to get relatively good results. NOTE See mental ray for Maya reference documentation, Scene Description Language section, Scene Entities sub-section, Options page for more information on various filter methods. Triangle More processor intensive than box, but offers even better results. Samples at the center of the pixel will have the highest contribution weight. As samples move further away from the center of the pixel, their contribution weight fall off linearly. This causes samples and details at the center of the pixel to be more "present" in the final computed pixel in the framebuffer. Gauss Produces the best results, but is the slowest to render. Gauss uses a curved fall-off for sample contributions. Almost all samples at the center of the pixel have virtually the same contribution weight, but rapidly falloff

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(smooth). Gauss requires a minimum filter size of 3 and this filter mode is know to make the images more blurry. Mitchell, Lanczos Mitchell (clip) and Lanczos (clip) are alternatives to Gaussian that offers slight variations in contrast (tends to increase). Mitchell increases less than Lanczos. Because “plain” Lanczos and Mitchell may produce negative values the new filter types are “clipped” variants to ensure positive values. The filtered result samples are clipped to the min/max range of input samples. The final pixel in the image will therefore not contain any out-of-range values _produced by the filter_, as might be the case for regular Mitchell and Lanczos filters. These filters tends to sharpen the final computed pixels. Therefore, if you want to enhance the image details, choose Mitchell and Lanczos as your filter method. Filter Size Controls the filter size used to interpolate each pixel in the rendered image. The larger the value, the more info from neighboring pixels. The larger the value, the more the image is blurred. The value should be at least 1,1. Filter size and filter mode are disabled whenever the Min Sample Level and Max Sample Level settings are below -1 0. mental ray for Maya does not filter when rendering using a Min Sample Level and Max Sample Level below these threshold values.

Sample Options Jitter Reduces artifacts by introducing systematic variations into sample locations. Without jittering, samples are taken at the corners of pixels or subpixels; jittering displaces the samples by an amount determined by lighting analysis. Sample Lock Locks the location in which you sample within pixels. When turned on, this option ensures that the sub-pixel samples occur at the same location within in each pixel, which is important to help eliminate noise and flickering results. Turn it off only if you get sampling problems, such as moire patterns.

Raytracing Raytracing Select raytracing as the secondary renderer so that, when the primary renderer (scanline or rasterizeror raytracing) detects that refractions or reflections are needed, it will switch to raytracing only mode. Raytracing can produce the most physically accurate reflections, refractions, shadows, global illumination, caustics and final gather.

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Reflections The maximum number of times a ray can be reflected off reflective surfaces. See also Max Trace Depth on page 420. NOTE Maya performs unlimited transparencies, but limited refractions. Refraction limits do not control transparency limits. The rasterizer has a special transparency control to either limit or expand transparency levels. This is particularly useful for sprite and hair/fur rendering. Refractions The maximum number of times a ray can be refracted through non-opaque surfaces. See also Max Trace Depth. TIP If refractions turn black, make sure Refraction is set to a high enough value. Max Trace Depth While the Reflections on page 420 setting and Refractions on page 420 setting each set the maximum number of times a ray can reflect or refract (respectively), this setting sets total number of penetrations that can occur regardless of whether the penetration is a result of reflection or refraction. For example, if reflections = 5, refractions = 5, but max depth trace = 4, then any combination of reflection and refraction bounces can take place, up to a maximum of 4. TIP The Max Trace Depth attribute applies only to refraction and not to transparency. Transparency is unlimited while refraction is limited by the Max Trace Depth. When raytracing is turned off, refraction becomes transparency and the Max Trace Depth is not applicable. Shadows The maximum number of times a shadow ray will penetrate a transparent or refracting object. Consider, as an example, a glass sphere and a metal sphere. The shadow of the glass sphere is not as dark as the shadow of the metal sphere because some light passes through the glass sphere. In mental ray, this model is represented by a shadow ray penetrating the glass sphere. The shadow ray only stops when one of the following is reached: 1) all light is blocked, 2) the number of times that the ray has penetrated the sphere is equal to the value of this attribute. Reflection/Refraction Blur Limit Determines the blurriness of secondary reflections or refractions. The higher the Reflection/Refraction Blur Limit, the more the secondary reflections/refractions are blurred.

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Acceleration Acceleration Method Select one of the following options: Regular BSP

The BSP (binary space partitioning) acceleration method recursively subdivides 3D space into a nested set of voxels, small boxes with triangles in them. It is efficient, but careful attention should be given to the size and depth parameters, which can have a large impact on speed and memory usage. See also Use average BSP (mental ray for Maya) settings on page 248. Large BSP Use for very large scenes. It breaks the scene into small data blocks that do not need to be stored in memory at all times. However, it may increase rendering time. BSP2

This is the default. BSP2 stands for Binary Space Partition, second generation. It enables a new BSP raytracing acceleration designed to cope with large scenes. BSP2 does not need to adjust any attributes like the old generation BSP and Large BSP, which frees the user from the tedious tuning required to achieve optimal rendering performance. BSP2 can be used whenever instances are heavily used in a scene. If you choose the grid acceleration method, which is no longer exposed in mental ray for Maya but is still accessible from the mental ray standalone command line, mental ray defaults back to BSP2 internally.

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BSP BSP Size Determines the maximum number of triangles in one bsp voxel. If you decrease this number, you will have more voxels and a heavier bsp structure, resulting in higher memory usage and better performance. BSP Depth Determines the maximum number of voxel subdivisions. Separate Shadow Bsp This option enables mental ray for Maya to use a secondary Bsp tree for objects that have low-detail shadow stand-ins to improve performance. Diagnose Bsp Shows the cost of creating and traversing the BSP tree used for raytracing. Both the depth and the leaf size can be visualized. If the diagnostic image shows that mental ray has been operating near the limit in large parts of the image (indicated by red or white pixels), this helps tuning the BSP parameters in the options block.

Rasterizer Rasterizer Transparency

If set to a positive value, then the transparency compositing for the rasterizer ends at the specified depth. This can be used to tune performance for scenes where it is known that the main color information is provided by the first few depth layers. It also allows you to limit the amount of hair/fur being rendered. You should exercise caution as you lower the transparency depth, since it is possible for the final pixel intensity to shift as less surfaces are contributing to the final pixel.

Shadows Shadow Method Select one of the following options: Disabled Select this option to turn shadows off. This option is automatically selected if shadows are disabled under the Quality tab. Simple (Unsorted Occluders) Enables simple shadows, which are standard for the provided libraries. This is the most efficient of the three shadow modes.

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If shadows overlap because multiple objects obscure the light source, the order in which these objects are considered (and their shadow shaders are called) is undefined. If one object completely obscures the light, no other obscuring objects are considered. NOTE When you use Simple shadows, you are limited to only one shadow ray per light source. Therefore, if you want to create soft shadows, which require more than one shadow ray to be cast, you should use Segments shadows instead. Sorted (Presorted Occluders) Enables shadow sorting. Similar to Simple, it ensures that the shadow shaders of obscuring objects are called in the correct order, object closest to the illuminated point first. This mode is slightly slower but allows custom shadow shaders to record information about obscuring objects. If no such custom shader is used, this mode offers no advantage over simple shadow on. Segments (Traced Occluders) Like Sorted, the shadow shaders are called in order. Shadow rays are traced much like regular rays, passing from one obscuring object to the next, from the light source to the illuminated point; each such ray is a shadow segment. Use this mode if you want volume effects (like fluids, particles, fur and smoke) to cast shadows. This mode requires support from the shadow shader, which must use the mi_trace_shadow_seg function to cast the next shadow ray segment. For more information about the mi_trace_shadow_seg node, see the mental ray Shaders Guide in the Maya Help. NOTE The Shadow Method is set to Simple by default. Simple shadows are not compatible with volume effects such as fluids, volume fur, particles and volume shaders and therefore may not render shadow volume effects correctly. Shadow Linking You can reduce the rendering time required for your scene by linking lights with surfaces so that only the specified surfaces are included in the calculation of shadows (shadow linking) or illumination (light linking) by a given light. NOTE You can also use render pass contribution maps for light and shadow linking. For instance, if you have a scene with 150 lights associated to your render layers, and you create a simple pass contribution map where only one light is associated with it, only that light is evaluated by the shader. For more information regarding render pass contribution maps, see Multi-render passes on page 187 Use the drop-down list to select one of the three choices available with this option:

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■

On

■

Obeys Light Linking

■

Off

The shadows in your scene can obey only one of light linking or shadow linking and not both. Therefore, you must decide whether to incorporate light linking or shadow linking in your scene and make your selection from the drop-down list accordingly. You can also render part of your scene using the default settings (instead of obeying the links that you have created). Select Off so that all links that you have established using shadow linking or light linking are ignored. The default is set to Obeys Light Linking. See Shadow linking for more information regarding shadow linking. See Light linking for more information regarding light linking.

Shadow Maps Format Select one of the following options: Shadow Maps Disabled Select this option to turn off shadow maps. Regular (OpenGL Accelerated) Causes mental ray for Maya to use OpenGL acceleration (if available with your graphics hardware) when rendering shadow maps. The same limitations apply as mentioned with the Scanline on page 407option. Shadow maps rendered with this option contain slightly different information from those generated with the regular (On) algorithm, and the soft areas of shadows tend to be smaller. Some areas may incorrectly be determined to not be in shadow. When OpenGL rendering of shadow maps is enabled, only the local workstation (master) participates since the computation cost of the map is so small that the networking overhead would be more costly. Detail / Regular The Detail shadow map option is a combination of features from regular shadow maps and raytraced shadows, meaning that it collects more information about shadow-casting objects. Unlike the regular shadow map, a detail shadow map also takes into account surface and lighting properties, such as transparency. Detail shadow maps store a list of depth values together with the light transmission coefficients

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at each depth. This provides similar quality shadows as raytraced shadows, but at processing times similar to depth map shadows. Detail shadow maps may require more time to calculate because they compute and store more per-pixel information. NOTE Detail shadow maps are more sensitive to the Softness attribute (in the Attribute Editor, Shadow Map Attributes section for the light shape node). A large Softness value results in a penumbra spread well beyond the shadow area.

Rebuild Mode Determines whether all shadow maps are recomputed. Reuse Existing Maps Shadow maps are loaded from files or reused from previously rendered frames if possible. Otherwise, created from new. Rebuild All and Overwrite Shadow maps are recomputed and the existing points are overwritten by the recomputed points. This is the default option. Rebuild All and Merge Specifies that shadow maps should be loaded from files, if available. The default shadow map calculations are still performed and the existing points are overwritten by the recomputed points, but only if the new points are closer to the light source. This option is useful for building shadow maps for use in multi-pass rendering because it allows shadow maps from a previous render pass to be reused for the current pass. Only shadow map changes are recalculated, not the entire shadow map. Motion Blur Shadow Maps Determines whether shadow maps should be motion blurred so that moving objects cast shadows along the path of motion. Turning this option off (default is on) can cause shadow maps to render slightly faster. NOTE Since shadow maps do not deal with transparent objects and motion blurring introduces a form of transparency at the edges, shadow map shadows can appear too large in the direction of motion if the object moves quickly. Rasterizer Pixel Samples

Controls the anti-aliasing quality when computing shadow maps with the rasterizer. This attribute sets the samples collect option for shadow map rendering to the specified value. A value of 0 uses the rasterizer default for shadow map rendering.

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Motion Blur See also mental ray for Maya motion blur on page 180.

Motion Blur Select one of the following options: Off Turns motion blur off. No Deformation No Deformation only considers the position of objects at the Shutter beginning and end point (open and close points). It performs object-based interpolation and is fast but limited. Full Full is slower to render, but gives true (that is, exact) motion blur results. Each deformed surface is being translated "per vertex", instead of per object transform. Select this method for motion blur of objects being deformed by animation, such as jiggling arms and jello-like motions, where the vertices are moving and jiggling as the animation occurs.

Motion Blur By This is a multiplier used to amplify the motion blur effect. Increasing this value reduces the realistic results achieved, but may produce an enhanced effect if that’s what you want to achieve. The higher the value, the longer the time interval used in the motion blur’s computation. Shutter Open, Shutter Close Defines the point in time at which the shutter opens and closes within the frame interval to control motion blurring.

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The defaults for Shutter Open and Shutter Close are 0.0 and 1.0, respectively. If the values for Shutter Open and Shutter Close are equal, motion blurring is disabled; if Shutter Close is greater than Shutter Open, motion blurring is enabled. The normal range is (0, 1), which uses the full length of the motion vectors or motion vector paths. It can be useful to set both to 0.5, which disables motion blurring but renders with an offset of one half frame, which allows bidirectional post-blurring in an output shader. NOTE The mental ray for Maya renderer draws its shutter setting from this section in the Render Settings window, unlike the Maya renderer (for which the shutter setting is on the camera). Motion Blur Shadow Maps Determines whether shadow maps should be motion blurred so that moving objects cast shadows along the path of motion. Turning this option off (default is on) can cause shadow maps to render slightly faster. NOTE Since shadow maps do not deal with transparent objects and motion blurring introduces a form of transparency at the edges, shadow map shadows can appear too large in the direction of motion if the object moves quickly.

Quality See also mental ray for Maya motion blur on page 180. Displace Motion Factor

Controls the fine displacement quality according to the amount of visual motion. Allows a reduction in tesselation density as objects move faster. This option is compatible with all renderer types: raytracing, scanline and rasterizer. For moving polygonal objects with displacement, this attribute automatically controls the quality of displacement according to the amount of visual motion.

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For fast moving objects, images with comparable visual quality may require fewer displacement tessellation details as compared to static or slow moving objects. Although it is also possible to tweak displacement approximation on a per-object basis, this process is tedious and is rarely done in practice. Per-object granularity may also not be fine enough to accommodate objects with different amount of motion in different parts. This attribute provides an automatic way of adjusting the displacement quality according to the amount of motion for a given object part. For view-dependent fine poly displacement, the adaptive subdivision checks for the motion length in screen space. The measured motion length is used to modify the use of the approximation constant. Geometry is reduced only in the areas of the object with strong motion. This attribute modifies the amount of geometry reduction as compared to the static case. A value of 0 disables the feature. 1 is the default and higher values provide more reduction. The simplification of geometry has an effect on motion of approximately 16 pixels. For slower motion, higher values should be used. For example, the factor value of 8 reduces geometry in areas with objects moving at the speed of 2 pixels per frame. Motion Quality Factor When you use the rasterizer with motion blur, you must decide between using higher values, which yield better quality, and lower values, which yield a faster render. Setting this attribute to values larger than 0.0 automatically lowers shading samples for fast-moving objects, at a rate proportional to the magnitude of the setting and the speed of the instance in screen-space. You should exercise caution when tuning this value, but 1.0 (the default) provides a good starting point. A value of 0.0 disables the setting. Motion Steps See also diagram in Shutter Open, Shutter Close on page 426. If motion blurring is enabled, mental ray can create motion paths from motion transforms, much like multiple motion vectors on vertices can create motion paths. This option specifies how many motion path segments should be created for all motion transforms in the scene. The number must be in the range 1 to 15. The default is 1. Time Samples Primary control for the quality of motion blur. This attribute defines the number of temporal shading samples per spatial sample. Increasing the number of samples gives better quality of motion blur. However, increasing the number of samples also increases rendering times. Spatial samples are samples taken from the perspective of the xy plane of the image. For still images, spatial samples are affected by the Anti-Aliasing Quality controls. At each spatial sample location, mental ray can take a number of temporal samples. Temporal samples are samples that are taken at different

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times between shutter open and close and add an extra dimension, time, to the x and y dimensions of spatial samples. Each spatial sample at location x,y is a combination of multiple temporal samples, each taken at a different time. Time Contrast These settings determine a threshold for adaptive time sampling. Lower values cause more time samples, which result in more accurate motion blur but increased render times. NOTE This attribute is not for use with the rasterizer. In general, use of the Time Samples attribute should be enough to control the quality of motion blur.

Motion Offsets Custom Motion Offsets Turn on this option if you want to set values for Motion Back Offset and Static Object Offset. Use these custom motion offsets to define the time steps where motion blur information is captured. This option is off by default. Motion Back Offset This value determines the start point of the time interval used for motion blurring. It is an offset to the current time in frames. The default value is 0.5, and corresponds to Maya. Static Object Offset This value determines the time used to render static objects. The default value is 0, and corresponds to Maya.

Framebuffer Primary Framebuffer Data Type Select the kind of information the framebuffer contains. Each image file format supports one or more data types. In addition, each file format is associated with a default data type. If you select a data type that is not supported by the file format that you have chosen, then mental ray for Maya will use the default data type associated with the file format instead. For example, if you have chosen to save the image as a tif file, but you have selected RGBA (Half) 4x16 Bit as your data type, then mental ray for Maya will render as an 8-bit RGBA (the default data type) instead, since RGBA (Half) 4x16 Bit is not supported by the tif format. For a list of data types supported by each file format, refer to the mental ray documentation. NOTE When creating multi-render passes, this is the MasterBeauty pass. Gamma Use this setting to apply gamma correction to rendered color pixels to compensate for output devices with a nonlinear color response. Inverse

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gamma is applied to textures as well. The reverse correction is applied to all quantized texture images. All R, G, B, and alpha component values are raised to 1overgamma_factor. The default gamma factor is 1.0, which turns gamma correction off. NOTE The behavior of the Gamma correction on page 398 attribute for the Maya software renderer is the reverse of that of the Gamma attribute for the mental ray renderer. mental ray Gamma is basically an un-gamma, where it removes Gamma correction to ensure it is in linear space prior to computing raytracing. Therefore, mental ray Gamma is not a display gamma, but an ungamma feature. For the Maya Software renderer, a higher gamma value lightens the mid-tones of the image. For the mental ray renderer, a higher gamma value darkens the mid-tones of the image.

Colorclip Controls how colors are clipped into a valid range [0, 1] before being written to a non-floating point frame buffer or file. In all modes, the RGB components are clipped as specified by the desaturate option. The RGB and alpha modes ensure that the resulting color is a valid premultiplied color. Clipping occurs only in 8-bit integer and 16-bit integer frame buffers. if you are using float and half-float, no clipping occurs. RGB RGB is first clipped to [0, 1] and alpha subsequently to [max(R, G, B), 1]. Use RGB if the alpha channel is considered less important than preserving the RGB color and intensity. Alpha Alpha is first clipped to [0, 1] and RGB subsequently to [0, A]. Alpha mode is intended for alpha compositing, where the alpha channel is more important than the absolute color value to preserve correct transparencies. Raw (default) RGB and A are both clipped to [0, 1] independently of each other. Use Raw mode only if no layering based on alpha is going to take place. This mode turns Premultiply on, so use it with care because shaders might receive colors that cannot be composited in standard ways. Interpolate Samples This option causes mental ray for Maya to interpolate sample values between two known pixel sample values. If interpolation is turned off, the last sample value in each pixel is stored, and pixels without samples get a copy of a neighboring pixel. When this option is turned on, the resulting image has a higher quality, but takes more time to process. This option is on by default.

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Desaturate If a color is output to a frame buffer that does not have 32-bit (floating-point) and half-float (16-bit float) precision, and its RGB components are outside the range [0, max], mental ray clips the color to this legal range. If desaturation is turned off (on by default), the individual components are simply clipped into range. Otherwise, mental ray tries to maintain the brightness of the color by moving it towards the grayscale axis of the color cube, until the RGB components are in the legal range. The max is determined by the colorclip mode. Premultiply If this option is on (default), premultiplication takes place (see Premultiplied images on page 78). If on, mental ray for Maya renders objects so that they are not anti-aliased against the background. For example, a pixel on the edge of an object is not mixed with the background color. (In TIFF terms, Maya generates unassociated alpha.) The premultiply off option instructs mental ray to always store colors unpremultiplied into frame buffers and files. When this option is off, mental ray does not premultiply the textures or the output frame buffers. This option is ignored if the colorclip raw mode is in effect. Dither mental ray for Maya supports 8, 16, or 32 bits per color component. In some cases, 8 bits per pixel, as supported by all popular picture file formats, can cause visible banding when the floating-point color values calculated by the material shader are quantized to the 8-bit values used in the picture file. Dithering mitigates the problem by introducing noise into the pixel such that the round-off errors are evened out. Note that this can cause run-length encoded picture files to be larger than without dithering. Dithering is turned off by default. Rasterizer use opacity

When using the rasterizer, enabling this setting enforces transparency/opacity compositing to be performed on all color user framebuffers (in other words, non-primary color buffers) regardless of the individual setting on the framebuffer. By default, only the primary color frame buffer and explicitly marked user buffers are considered for rasterizer compositing. This option may be used in combination with the user framebuffer interface in Maya 2008 or below. You must enable this option to ensure that the rasterizer renders passes that are identical to those rendered using raytracing/scanline (primary renderer).

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Contrast All Buffers

Use in conjunction with the multi-render passes feature. See Multi-render passes on page 187for more information. Occasionally, you may notice aliasing on the edges of your render passes that does not exist in your overall beauty pass. Mental Ray's adaptive sampling algorithm analyzes the local contrast in the rendered image to determine whether or not a given image region requires finer sampling. This is a performance optimization technique that allows mental ray to sample the image more coarsely in regions of uniform color, and finely in areas that contain detail, such as object edges and intricate textures. Therefore, this algorithm may yield aliasing in render passes that contain high contrast detail in areas where the master beauty pass is smooth. Enable this option so that the adaptive sampling algorithm analyzes the contrast in all color frame buffers being rendered, rather than for just the master beauty pass. The render may be faster when the option is turned off, at the risk of compromising image quality when the multi-render pass workflow is used.

Indirect Lighting tab Environment Image Based Lighting When you click the Create button, a new IBL node is created, replacing any currently connected node. (Though multiple IBL environments can exist in a scene, only one can be used at a time.) For more information, see Image-based lighting (sky-like illumination) and also Render infinitely distant (sky-like) illumination and reflection in the Lighting guide. For descriptions of the attributes in the IBL node, see Image based lighting node attributes in the Lighting guide.

Physical Sun and Sky When you click the Create button, a network containing the mia_physicalsky, mia physicalsun, mia_exposure_simple and directionalLight is created. Maya automatically connects all the necessary attributes from the four nodes for you. This network is connected to all existing renderable cameras.

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The Attribute Editor for the mia_physicalsky shader also contains two buttons that allow you to edit your camera connections. Choose between Update Camera Connections and Remove Camera Connections. For more information, see Simulating the sun and sky and Adding sun and sky to your scene of the Lighting guide. NOTE Image based lighting and physical sun and sky are not designed to work together at the same time. It is therefore recommended that you either use one or the other.

Global Illumination Global Illumination Use this to turn on or off (default) Global illumination, a process that allows for indirect lighting and effects like color bleeding. The default is off. Global illumination is computed only for light sources for which photon emission is enabled. Accuracy Change the number of photons used to compute the local intensity of global illumination. The default number is 64; larger numbers make the global illumination smoother but increase render time. Scale Use this setting to control the influence of indirect illumination effects for global illumination. You can select a color with the Color Chooser or use the slider to set the Scale value. Scale is off by default. Radius Controls the maximum distance at which mental ray for Maya considers photons for global illumination. When left at 0 (the default), mental ray for Maya calculates an appropriate amount of radius, based on the bounding box size of the scene. If the result is too noisy, increasing this value (to 1 to start, then by small increments up to 2) decreases noise but gives a more blurry result. To reduce the blur, you must increase the number of global illumination photons (Global illumination Accuracy) emitted by the light source. Merge Distance

The photons within the specified world-space distance are merged. For scenes with uneven photon distribution, this attribute can greatly reduce the size of your photon map.

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Caustics Caustics Turn caustics on or off (default). Caustics are produced only by light sources for which photon emission is enabled. The material shader (which must have a non-zero diffuse component) that receives the caustics must be set to receive caustics. Accuracy Controls the number of photons used to estimate the caustic brightness. The default is 64. Higher settings (up to 100 to start, tested in small increments) larger numbers make the caustic smoother. Scale Use this setting to control the influence of indirect illumination effects for caustics. You can select a color with the Color Chooser or use the slider to set the Scale value. Scale is off by default. Radius Controls the maximum distance at which mental ray for Maya considers photons for caustics. When left at 0 (the default), mental ray for Maya calculates an appropriate amount of radius, based on the bounding box size of the scene. If the result is too noisy, increasing this value (to 1 to start, then by small increments up to 2) decreases noise but gives a more blurry result. To reduce the blur, you must increase the number of caustic photons (Accuracy) emitted by the light source. Merge Distance

The caustic photons within the specified world-space distance are merged. This attribute can greatly reduce the size of your caustic photon map.

Caustic Filter Type Controls the sharpness of the caustics. Filtering increases the weight of photons that are close to the point of interest, and reduces the amount of blur at the edges of a caustic. Box Generally makes caustics looks sharper. It is faster, but less precise. Cone Generally makes caustics looks smoother. It is more precise, but slower. Gauss Caustic Filter Kernel The bigger the kernel, the softer the caustic.

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Photon Tracing Photon Reflections Use this to limit the number of times a photon will reflect in a scene (after the first bounce, which is taken care of by direct illumination). It works in conjunction with Max Photon Depth on page 435. Photon Refractions Use this to limit the number of times a photon will refract in a scene (after the first bounce, which is taken care of by direct illumination). It works in conjunction with Max Photon Depth on page 435. Max Photon Depth Use this to limit the number of times a photon will bounce around (reflect or refract) after the first bounce (which is taken care of by direct illumination) in a scene. Default is 5, but correct value depends on how many surfaces the photon must go through or bounce off of before hitting a diffuse surface to stop. For example, if a photon goes through 6 transparent surfaces, the default 5 would produce incorrect results. After the depth trace limit has been met, photons are not re-emitted and instead are absorbed. Custom shaders may override these values.

Photon Map Rebuild Photon Map If a filename is specified for the photon map (in Photon Map File on page 435), the map is loaded and used (providing the file exists). If this option is turned on, any existing file will be ignored, and the photon map will be recomputed and an existing file will be overwritten. The default is off. In other words, if you want to build a map, turn this option on; if not, turn this option off and specify the file to be used in Photon Map File on page 435. Photon Map File Specify the photon map file that mental ray for Maya should use as the current photon map. It will be loaded and used without computing a new photon map. If the photon map file does not exist, one will be created and saved. Enable Map Visualizer Causes Maya to create a visualization of stored photon and final gather maps. The visualization appears in the scene view immediately after rendering is complete. See Final Gathering Map on page 439. Direct Illumination Shadow Effects This should be turned ON if you use transparent shadows with Global illumination and, or caustics. The attribute does not affect performance if the scene does not use any shadow effects (for example, material shaders setting shadow attenuation).

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By default, mental ray automatically detects if additional shadow shaders should be exported to render shadow effects such as attenuation and colored shadows. For global illumination, this procedure is disabled by default, since shadowing should already result from indirect lighting and caustics with photons. But the shadow attenuation effect through transparent objects is not easily achievable with global illumination. This option enables shadow effects detection, and produces shadow effects from direct lights in addition to indirect shadowing from photons.

Diagnose photon Select one of the following options: Density When photon maps are used, select this option to replace all material shaders in the scene with an internal shader that produces a false-color rendering of the photon density. Irradiance When photon maps are used, select this option to replace all material shaders in the scene with an internal shader that produces a false-color rendering of the average of the red, green and blue irradiance components. Photon density Shows a false color rendering of photon density on all materials. This is useful when tuning the number of photons to trace in a scene, and to select the optimum accuracy settings for estimation of global illumination or caustics. It also works well in combination with the Grid Mode.

Photon Volume Photon Auto Volume Check this option to enable a volume-tracking mode that keeps track of the volumes that the camera is in and takes over inside/outside decisions. This option helps render a camera passing through volumes such as light cones from streetlights. Accuracy Controls how the photon map is used to estimate the intensity of caustics or global illumination within a participating medium. It applies to photon volume shaders, which compute light patterns in 3D space, such as volume caustics created by focused shafts of light cast by objects acting as lenses. Radius Controls the maximum distance at which mental ray for Maya considers photons for a participating medium. Merge Distance

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The volume photons within the specified world-space distance are merged. For scenes with uneven photon distribution, this attribute can reduce the size of your volume photon map.

Importons Importons

Enable this option to turn on importon emission.Importons are particles similar to photons. However, they are shot from the camera and traverse the scene in the opposite order. Instead of energy, they hold a quality which is an importance of the contribution to the final image. The information from importons is used by the kernel for distribution of rendering efforts according to the final contribution to the rendered image, in other words, importance-driven sampling. Importons are thus a foundation for new view-dependent indirect illumination techniques. Density Number of importons shot from the camera per pixel. The minimum value for this attribute is 0.02, which is approximately 1 importon per 50 pixels. The default and recommended value is 1. Lower values speed up importon emission but could also decrease final image quality. Merge Distance The importons within the specified world-space distance are merged. The default value is 0, which means that merging is disabled. Max Depth Controls the diffusion of importons in the scene. If set to zero, importons will not scatter on the diffuse bounces. The default is zero. In some cases you may need to use more than a single diffuse bounce, for example, when you are using final gather, or when the Traverse option is disabled. Traverse Enable this attribute so that importons are not blocked by even completely opaque geometry. Instead, they are stored for all intersections with geometry on the ray from the camera to infinity. This leads to a significantly higher number of importons stored in the scene. However, it removes the discontinuity in the distribution of the importons originated from the visibility to the camera function.

Final Gathering Final Gathering Use this to turn Final Gathering for global illumination on or off. The default is off. Final gathering is a different means of calculating

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indirect illumination. For more information, see Final gather in the Lighting guide. Accuracy Controls how many rays are shot in each final gathering step to compute the indirect illumination. The default is 100 per sample point. Higher values are required for final renders. Increasing the value reduces noise but also increases the rendering time. NOTE When the Final Gather Accuracy is changed, the Primary Final Gather File on page 439is always ignored and new Final Gather rays are emitted. You can see, in the Output window, when this happens: ■

RCFG 0.2 info: finalgMap/test1:final gather options differ from ones currently used, content ignored.

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RCFG 0.2 info: overwriting final gather file "finalgMap/test1".

Point Density Controls the number of final gather points to be computed, performing the full and time-consuming final gather tracing. Point Interpolation The number of final gather points to be considered for interpolation at a shading sample during rendering. Higher values smooth the final gathering result at little cost. Primary Diffuse Scale The Scale value allows you to easily control the intensity and color of the final gather contribution on a global scene level. You can use the Color Chooser or use the slider to set the Scale value. Secondary Diffuse Scale Scale the contribution of final gathering secondary bounce to the final render result. Secondary Diffuse Bounces Use this attribute to set multiple diffuse bounces for final gathering. This option controls whether indirect diffuse lighting contributes to final gather, up to a sum of the Final Gather Reflection and Final Gather Refraction values. Use this attribute to add more light and color bleeding to your final gather results. Also, use this option to prevent unnatural darkening of corners in your scene. The higher the value, the longer the final gather computation process.

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Final Gathering Map Rebuild If this is on (default), any previously generated Final Gather file is ignored and all final gather points are recomputed. See Primary Final Gather File on page 439for more information about the file. If this file is off, Final Gather is forced to use the results from a previous Final Gather render. Existing final gather points are not recalculated, and any new final gather points are appended to the existing file. Freeze The Freeze option stops any new data from being written to the final gather file. It is useful to reduce light flickering in your animation. See Troubleshoot final gather causes flicker on page 283. TIP ■

If you are rendering out a still image and are not changing the Final Gather settings, turn this attribute off to save rendering time.

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If you are rendering out a camera animation sequence, you may be able to use previous frames’ Final Gather results (that is, you can turn this attribute off), depending on how the irradiance changes during the animation. However, if objects in the scene move, this option must be on.

Primary Final Gather File This is the file that stores the Final Gather results that mental ray for Maya can use for irradiance lookups. You can reuse Final Gather results from a frame rendered earlier, or from a previous scene render: ■

If no filename is specified and Rebuild is turned on, rendered results are placed in a default file.

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If you specify previously non-existent filename, the rendered results are placed in the file with that name.

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If you specify an existing filename here, and Rebuild is turned on, the specified file is overwritten with the newly rendered Final Gather results.

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If you specify an existing filename here, and Rebuild is turned off, the newly rendered results are appended to the existing file. (This means that the file may grow without bounds.)

Secondary Final Gather File

You can provide several final gather map files as lookup map files for the rendering. You can therefore use the final gather map rendered from different cameras and combine the lookups at render time. Also, a secondary final gather map can be used to lookup final gather map files from different frames. For example, you can make the primary final gather map file lookup the final gather map file for the current frame T, and the secondary final gather map file to look up other final gather map files from other frames such as T+1 and T-1 (assuming that you have pre-generated a final gather map file using the Render Mode Final Gathering Only). Enable Map Visualizer Causes Maya to create a visualization of stored photon and final gather maps. The visualization appears in the scene view immediately after rendering is complete. See Photon Map on page 435. Preview Final Gather Tiles If turned on, this setting lets you see tiles as they render. That is, you can see the image as it renders. Precompute Photon Lookup This option (which also turns on Final Gather) causes photon tracing to compute and store an estimate of the local irradiance at every photon location. This means that far fewer final gathering points are required because the photon map carried a good approximation of the irradiance in the scene—mental ray for Maya can estimate irradiance with a single lookup, instead of many photons. In this case, photon tracing takes longer than before and requires slightly more memory, but rendering is faster. Diagnose finalgather This option allows you to render by final gathering points in green for initial raster-space, and in red for render-time final gathering points. This is useful in fine tuning final gather settings to distinguish between view dependant and non-view dependant results to better distribute final gather points. This option is off by default.

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Final Gather Quality Filter Use this to control how Final Gather uses a speckle elimination filter to prevent samples with extreme brightness from skewing the overall energy stored in a Final Gather sampling region. Neighboring samples are filtered so that extreme values are discarded in the filter size. By default, the filter size is 1. Setting this to 0 disables speckle elimination, which can add speckles but will better converge towards the correct total image brightness for extremely low accuracy settings. Size values greater than 1 eliminate more speckles and soften sample contrasts. Sizes greater than 4 or so are not normally useful. Falloff Start, Falloff Stop Use these settings to limit the reach of indirect light for Final Gather (but not photons). If no object is found within a distance of start, the ray defaults to the environment color. Objects farther away than stop from the illuminated point will not cast light. An extra advantage is that this speeds up final gather computation, since final gather does not evaluate all visible surfaces, but only the ones visible within defined ranges.

Final Gather Tracing Reflections Use this to limit the number of times subrays will reflect in a scene. It works in conjunction with Max Trace Depth on page 441. Refractions Use this to limit the number of times subrays will refract in a scene. It works in conjunction with Max Trace Depth on page 441. Max Trace Depth Use this option to specify the number of subrays for the final gather render. The default is 0, which means that indirect illumination computed by final gathering cannot pass through glass or bounce off mirrors, for example. A depth of 1 would allow a single refraction or reflection. Typically, a depth greater than 2 is not necessary. Optimize for Animations Enable multi-frame final gather mode to reduce flickering in animation. The accuracy of the render may suffer in some parts of the animation because a constant number of final gather points is used for the entire animation and therefore some parts of the scene may not contain the sufficient number of points. This option sets the final gather mode to multiframe. See Final Gathering Modes in the mental ray for Maya reference guide for more information. Use Radius Quality Control Switch back to the first generation final gather algorithm where the radius is used to control final gathering sampling and interpolation.

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Min Radius, Max Radius Max Radius and Min Radius control the size of the sampling region within which Final Gather rays search for irradiance information from other surfaces. With the default values, Maya calculates values that seem appropriate based on scene dimensions to speed up the render, but this calculation doesn’t allow for complex geometry. Generally, enter a value that is 10% of scene’s overall dimension for the Max Radius, then enter 10% of that for Min Radius. Make further adjustments based on scene geometry detail, how the geometry is arranged in the scene, and how the render looks. For example, use these settings to achieve better diffuse detailing in nooks and crannies in your scene. View (Radii in Pixel Size) This option causes the Min Radius and Max Radius of final gather rays to be calculated in pixel size, rather than in object space. This allows you to set the visual quality in pixel size, without knowing the object or scene bounds.

Irradiance Particles

Irradiance particles is a global illumination technique which is sometimes superior to final gather and/or photon mapping in terms of image quality, usability and performance. Before rendering, importons are shot to the scene from the camera. Data regarding their hit positions with information on the amount of direct (and possibly indirect) illumination coming at their position (hence the name "irradiance particles") are combined into a map. One or more passes of indirect illumination can be computed. During rendering, Irradiance Particles are used to estimate the irradiance for every shading point. If only direct illumination is collected for irradiance particles, then this is equivalent to one bounce of indirect lighting. Irradiance can also be interpolated from precomputed values at particle positions. Irradiance Particles cannot be used in combination with global illumination and final gathering However, Irradiance Particles are compatible with caustic photons. Irradiance Particles Select to enable irradiance particles. Rays The number of rays shot while estimating the irradiance. This attribute is similar to the number of rays used for final gathering, but instead, it specifies the maximum number of rays and delivers better quality than final gathering

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does with the same number of rays. The minimum value is 2 and the default value is 256. Indirect Passes The number of possible passes of indirect lighting. If >0, then a sequence of passes is computed to collect the irradiance coming from multiple indirect illumination bounces and irradiance Particles would have both direct illumination and indirect illumination information. If =0, then Irradiance Particles will only have direct illumination information. The default value is 0. Scale Global scale factor applied to the intensity of the irradiance during rendering. Values other than the default do not lead to a physically correct rendering but are useful for artistic purposes. The value is expanded to a color having the same R, G and B components. The default value is 1.0. Interpolate Controls the use of interpolation. Choose among no interpolation, interpolating always, or interpolate only for secondary rays (that is, no interpolation for eye rays and interpolation for reflections, retractions, and so forth). The default is always. Interpoints The number of irradiance particles used for the lookup interpolation. The default value is 64. Environment Enables the use of the environment maps for irradiance computation. A separate particle map is built for the environment (if an environment shader is present) and used during rendering for image based lighting. Env. Rays The number of rays used for the computation of irradiance coming from the environment map. The default for Env. Rays is the same as the number of Rays set for the Irradiance Particles option. For outdoor scenes, the default works fine, but increase this value for indoor scenes. Env. Scale Global scale factor applied to the irradiance contribution of the environment. The scaling factor is relative because it applies to the environment irradiance only. The environment irradiance can be further scaled (multiplicatively) if the user specifies a global scaling factor with the Scale option. The default value 1. Rebuild If enabled, mental ray for Maya computes the irradiance particle map even if a file with the specified name already exists. If disabled, mental ray reads the irradiance particle map from the specified file, or, it reuses the irradiance particle map that comes from the previous frame rendered. Disabling this feature is useful for animations, which are flicker-free. However, the irradiance particle map may lose quality if the objects and camera are moving, so this is only recommended for fly-throughs. In addition, since the

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particle map is view dependent, inaccuracies may show up on the frame image borders. This option is enabled by default. Map File Specifies the map file for the irradiance particle map. If the specified file exists, mental ray for Maya tries to read the irradiance particle map from this file (unless Rebuild is enabled). If the irradiance particle map is not successfully read from the file, mental ray for Maya computes it and saves it to a file with the given name. This behavior is consistent with the photon maps option.

Ambient Occlusion Ambient Occlusion

Enable ambient occlusion support. Computation is performed on demand of shaders only. NOTE You must enable ambient occlusion if you are creating an ambient occlusion render pass. See Multi-render passes on page 187for more information regarding render passes. Rays Number of ambient occlusion rays used for the computation of each ambient occlusion value. mental ray shaders using ambient occlusion API can override this value internally. Caching Control creation of the ambient occlusion cache in memory. If caching is disabled but the feature is enabled, then ambient occlusion is performed on demand only when shaders call for its computation. Cache Density Upper bound to the number of ambient occlusion points per pixel. Cache Points Number of cache points close to the lookup location used for interpolation. Default is 64.

Options tab Diagnostics Diagnose samples Shows how spatial supersamples were placed in the rendered image, by producing a grayscale image signifying sample density. This is useful when tuning the level and the contrast threshold for spatial supersampling.

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Diagnose Bsp Shows the cost of creating and traversing the BSP tree used for raytracing. Both the depth and the leaf size can be visualized. If the diagnostic image shows that mental ray has been operating near the limit in large parts of the image (indicated by red or white pixels), this helps tuning the BSP parameters in the options block Diagnose grid Renders a grid on top of all objects in the scene, in object, camera, or world space. Gives you an idea of the scene scale and rough estimates of distances and areas. Grid size Defines the size of the grid (in Diagnose grid).

Diagnose photon Select one of the following options: Density When photon maps are used, select this option to replace all material shaders in the scene with an internal shader that produces a false-color rendering of the photon density. Irradiance When photon maps are used, select this option to replace all material shaders in the scene with an internal shader that produces a false-color rendering of the average of the red, green and blue irradiance components. Photon density Shows a false color rendering of photon density on all materials. This is useful when tuning the number of photons to trace in a scene, and to select the optimum accuracy settings for estimation of global illumination or caustics. It also works well in combination with the Grid Mode. Diagnose finalgather This option allows you to render by final gathering points in green for initial raster-space, and in red for render-time final gathering points. This is useful in fine tuning final gather settings to distinguish between view dependant and non-view dependant results to better distribute final gather points. This option is off by default.

Preview Contains options for specifying what to include in a preview render in Render View. Please refer to the mental ray User Manual, available from the Maya help, for more information about this setting. Preview Animation Render subsequent frames of the set animation range and preview all intermediate images inside Render View. Preview Motion Blur Calculate and preview render motion blur if enabled in the Render Settings. The Preview Animation option doesn’t need to be turned on for this to work.

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Preview Render Tiles Updates the Render Preview window in regular time intervals to show render progress. If this is turned off, only the final image is shown at the end of rendering. Preview Convert Tiles This option enables a plug-in conversion procedure for previewing image tiles when the primary framebuffer type is of a type that is not supported by Maya’s Render View (for example, floating point framebuffers, or color framebuffers with components larger than 8 bit). The conversion procedure involves the clipping and rescaling (desaturation) of colors for display. This option is on by default. Preview Tonemap Tiles and Tonemap Scale The Preview Tonemap Tiles option previews image tiles for floating-point framebuffer types where the color values exceed the typical 0-1 range (because the color values are RGB). This option is on by default. The Tonemap Scale value is used to rescale the color data of image tiles prior to clipping. This is useful when rendering high dynamic range images. The final rendered image is not affected by this value. The default value is 1.

mental ray Overrides Displacement Max Displace Specifies the maximum displacement applied to object control points in a normal direction. This provides control over the otherwise automated displacement range to better focus tessellation where most needed. Set this value if you have any displaced objects in your scene. A Max Displace value that is too large results in a correct image, but takes more time and uses more memory. If the Max Displace value is too small, parts of the displaced object may be clipped. The default value of 0 means the setting is not active. A warning message appears if a displacement shader returns a value greater than the Max Displace value. This can result in rendered geometry appearing clipped.

Shadow Map Shadow Map Bias This option applies the specified Shadow Map Bias value to all light sources that do not have their own biases. This adds a slight offset to the shadow depths, resulting in a slightly shifted shadow. This option is useful in tuning shadows in specific cases, such as when rendering Fur.

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The bias value should be smaller than the smallest distance between a shadow caster and a shadow receiver. However, bias values that are too small may cause self-shadowing.

Global Illumination/Caustics Turn caustics and global illumination generators and receivers on or off for the entire scene.

Tessellation Use these options to create and assign a Surface and, or Displace approximation globally to the scene.

Translation Contains options for specifying the settings and items to be included when rendering a Maya scene with mental ray for Maya. NOTE In Maya 8.0, the Export Verbosity attribute was used to control the rendering verbosity. In Maya 2009, this control has been moved to the mental ray Render Option editor and the mental ray Batch Render Option editor. See Render > Render Current Frame on page 320 and Render > Batch Render on page 324 for more information. Export Exact Hierarchy Tries to preserve the DAG hierarchy during processing. This produces additional mental ray instgroup entities. There are certain unresolved material inheritance issues in this mode, but it works well in the general case. Deeply nested DAG hierarchies may be translated much faster compared to the standard Maya iterator mode that always flattens the DAG. Default is off. Export Full Dagpath Uses the full DAG path names instead of the shortest possible name for mental ray scene entities. This is not required to generate a valid scene, but ensures reproducible names even if DAG entity names are reused in Maya. On the other hand, with deeply nested DAG hierarchy names, you may exceed the maximum supported name length in mental ray. Default is off. Export Textures First Collects all file texture references in the scene first. This ensures that missing texture files are reported early in the process, but may slow down scene processing depending on the number of file textures being used. It may also write out textures references that are never used in the

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shading graph, because it doesn't perform a complete scene graph traversal for performance reasons. Default is on. Export Particles Lets you export particles. Export Particle Instances Lets you export particle instances. Export Fluids Lets you export fluids.

Export Hair Select one of the following options: Hair Geometry Shader The geometry shader creates the hair. This option should be used for rendering interactively in Maya and offers the best Maya Hair translation performance. Off Select this option if you do not want to export hair. Hair Primitive Select this option to convert Maya hair to native mental ray hair so that it can be rendered with mental ray standalone. This option can be used for rendering interactively in Maya or for exporting the file to render with standalone but better suited for mi file rendering. Export Post Effects Lets you export post effects. Export Vertex Colors Lets you force the export of all the CPV (color per vertex) data for all the meshes in your scene. Exporting CPV data can be process-intensive, so do not turn on this attribute unless necessary.

Performance (Performance options are within the Translation section.) Prune Objects Without Material This option ignores objects without materials during translation so that they are not part of the final rendered scene. This option is on by default. Optimize Non-animated Display Visibility This option ignores non-animated invisible scene entities during translation so that they are not part of the final rendered scene. This option is on by default. NOTE You should turn Optimize Non-animated Display Visibility off if an object’s visibility is animated. Optimize Animation Detection When this option is turned on, the processing of non-animated geometry is significantly optimized because mental ray for Maya detects animated nodes prior to processing the scene. This is

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especially useful for scenes that contain many static objects and only a few simply animated objects. This option is on by default. NOTE Optimize Animation Detection is limited in several ways, as it currently can only detect key frame animations, but not a) pre and post infinity curve cycles and b) animations generated by expressions and pre/post RenderMel scripts. Optimize Vertex Sharing This is to produce a more compact vertex representation (vertex lists) for meshes that exhibit a lot of vertex sharing. Only first-level sharing is exploited in mental ray for Maya. Optimize Raytrace Shadows This option optimizes the algorithm used to assign mental ray shadow shaders to materials. When turned on, mental ray determines whether shadow shaders are necessary before assigning the shader. This option is on by default. Export Render Proxy

Select this option to render the proxies in your scene instead of the placeholder geometry that you used. For more information regarding render proxies, see Using render proxies in your scene on page 242. Export Motion Segments This option enables detection and translation of motion vector segments of shape nodes, a method to render non-linear motion paths from shape animations with mental ray. If this option is enabled, then the Motion Steps on page 428option triggers this number of extra evaluations of the scene at equi-distant times within the Maya shutter interval (render camera shutter * motion blur by). Any shape deformation appearing in these time steps is expressed as a motion segment vector in mental ray. The resulting motion trail when rendering with motion blur matches the actual shape animation more closely, since it approximates any non-linear movement with a set of linear segments (up to 15). NOTE Raising the Motion Steps on page 428 value beyond 1 (the default) implies a performance degradation of translation caused by extra subframe scene evaluations in Maya and computations in the plug-in. Export Triangulated Polygons This option processes all polygon meshes as tessellated triangles, based on Maya’s tessellation. This allows more efficient use of memory so that large scenes with large polygon meshes render with less memory usage. This option is on by default.

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The Export triangulated polygons option automatically switches back to exporting mesh geometry if it encounters subdivision meshes in the scene.

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In some rare cases, Export triangulated polygons may cause a decrease in render quality. Turn this option off if this occurs.

Export Shape Deformation Compare actual geometry to determine any kind of shape deformation during animation and motion blur, required to produce exact motion blur information and support incremental changes in mental ray. If none of these conditions are true, turning this off may speed-up scene processing. Default is on. Force Motion Vector Computation

This option forces the computation of motion transform and per vertex motion vector. Normally, this is automatically done when you enable motion blur; however, if you do not want mental ray to render the motion blur effect, but you want the motion vectors and motion transforms to be available during rendering (without blurring the image), you can enable this option so that mental ray for Maya provides the motion data. For example, you must enable this option if you creating the motion vector type passes (2D Motion Vector, 3D Motion Vector, Normalized 2D Motion Vector). Export Polygon Derivatives Calculate and export first order derivatives for polygons. This is required for bump mapping and shader filtering to produce comparable results to Maya. When on (default), the Maya derivatives and Smooth Polygon Derivatives options are available. Maya Derivatives This option uses Maya’s derivatives calculation for bump mapping and shader filtering, providing compatibility with Maya. This option is off by default, and is only available when Export Polygon Derivatives is on. Smooth Polygon Derivatives This option calculates derivatives by taking into account vertex sharing to decide if texture seams can be ignored. This calculation avoids artifacts due to UV seams. This option is off by default, and is only available when Export Polygon Derivatives is on.

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Export Nurbs Derivatives Enable calculation of first order derivatives for NURBS objects in mental ray. This is required for bump mapping and shader filtering to produce comparable results to Maya. Default is on. Export Objects On Demand/Threshold Use the Export Objects On Demand option to control the processing of objects in your scene. This option is particularly effective in scenes that have objects beyond the view of the camera. In this case, mental ray does not process the objects beyond the camera view, therefore reducing processing time. When Export Objects On Demand is on, it includes a Threshold value that lets you tune on demand translation for objects. Objects with a number of vertices or controlled vertices greater than the threshold value are not translated until a ray hits the bounding box. A value of 0 results in all objects processed on demand. In this case, translation is quick, but render time may not improve. You can select larger objects for on demand translation by raising the Threshold value. For polygons, the Threshold value relates to the number of vertices. For NURBS, the Threshold value relates to the number of control points. For Hair, the Threshold value relates to the number of hair. This option is off by default.

Customization (Customization options are within the Translation section.) Please refer to the mental ray User Manual, available from the Maya help, for more information about this setting. Render Shaders With Filtering This option causes mental ray shaders to perform filtering in individual shaders. This option reduces texture and bump mapping artifacts, and is on by default. Render Shaders With Filtering requires that the Export Polygon Derivatives option be turned on (Render Settings window, Options tab, Translation > Performance section). Use Legacy Maya Base Shaders

Disable this option to use render pass compliant shaders. This option is off by default. Enable this option to use legacy Maya base shaders. Export State Shader This should only be turned off when exporting to .mi file and only the standard mental ray base shaders are used exclusively (for example, when no Maya shaders are used). Default is on.

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This option should be enabled when you use the multi-render pass feature. Export Light Linker This controls the export of the Maya Light Linker node. Default is on. Export Maya Options This enables the export of special options as mental ray user data, to control several advanced Maya features performed in the mayabase shaders. Default is on. Export Custom Colors Common mental ray shaders often use 4-component RGBA color parameters instead of the usual 3-component Maya color compounds. With this option enabled all custom nodes are provided with full RGBA colors, with the alpha component set to 1.0 (fully opaque). Default is off. If this option is disabled, then mental ray shaders should ensure that they can set the alpha component explicitly to reasonable values, away from mental ray’s default, which is 0 (fully transparent). Export Custom Text This should only be turned on for .mi file export to recognize and translate Custom Text nodes. It is automatically turned off for the integrated rendering if Preview Custom has been turned off. Export Custom Data If enabled, special custom attributes on polygon meshes are recognized and exported as vertex user vectors to mental ray. Export Custom Vectors This option enables recognition of an optional miCustomMotion boolean dynamic attribute on geometry shape nodes. If such an attribute has been found then motion vectors are always generated and exported, even if they are of zero length. This is required for certain mental ray shaders that are allowed to perform motion blur calculation in the shader, for example for displacement motion blur.

Custom Entities Contains controls for creating and managing custom global text, textures, and scene element text. Use these options to take advantage of alternate channel computations when writing custom shaders. Pass Custom Alpha Channel This option passes the mental ray alpha component of the final color as the alpha channel, ignoring the Maya alpha component. This is useful when a custom shader is producing an alpha value. This option is off by default. Pass Custom Depth Channel This option overrides the Maya depth channel calculation with the default mental ray depth channel calculation. This option

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is useful when you want to revert to using the mental ray depth calculation, instead of the default Maya calculation. This option is off by default. Pass Custom Label Channel This option passes label data untouched, rather than allowing adjustment for Maya shaders. This option is off by default.

Custom Globals These allow for the customized output of version, link, and include statements. If these text boxes are empty, mental ray for Maya generates the usual default statements that are required for rendering Maya scenes. Otherwise, it expects a space separated list of entries, which are exported in the appropriate section of the mi stream instead of the defaults. In the Versions text box, the first entry is written as the min version, the second entry as the max version statement. The Includes text base.mi mayabase.mi

in the text box results in: $include "base.mi" $include "mayabase.mi"

in the final output. The same happens for the Links text.

Custom Scene Text Global Text The global text control is especially useful for adding custom link, $include and code statements. It can also be used to add texture and shader declarations. Within a scene many types of text nodes can be created, but just the selected one gets exported. The contained text is written once at the beginning of the .mi stream right before the first option block gets written. Certain modes are available which determine how the custom text should be applied to the generated output. Note that incorrect .mi text could be introduced that cannot be recognized nor corrected by mental ray for Maya processing. Options Text Similar to Global Text, Options Text is provided to allow customized mental ray option settings. It offers the ability to extend or replace the generated option settings. For example, custom framebuffer statements should be added here.

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Lights, Cameras, and Scene Text These enable custom text on certain sequentially exported sections like lights section, camera section, and scene section, in this order. Those sections can be extended or completely replaced, similar to the Global Text. For example, custom lights can be appended to the generated output. This would require that the scene section be extended with the incremental change of the new root instance group including the new light. Root Group Text The Root Group Text control can be used to customize the final root group specifying all cameras and objects to be rendered. This control is applied to the content of the root group, not the whole root group section (like other types of scene text). Render Text The Render Text control can be used to customize render commands for renderable cameras. For example, it can be used to perform operations between renderings, like file operations.

Render Settings: Maya Hardware tab For information on the render settings, see Render Settings window on page 376.

Quality For more information about render speed and image quality, see The speed/quality tradeoff on page 153.

Presets When you select a Preset here, settings in the applicable sections in the rest of the tab are automatically set. Use these settings as a starting point for rendering your image at a given quality and with a certain effect. At higher quality settings, objects appear smooth, but may take more time to render. At lower quality settings, objects may appear a little more jagged, but render quickly. Custom Lets you specify the hardware quality settings independently. Preview quality The Number Of Samples is set to 1. Color resolution is set to 128.Bump resolution is set to 256. Intermediate quality The Number Of Samples is set to 1. Color resolution is set to 256. Bump resolution is set to 512.

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Production quality The Number Of Samples is set to 9. Color resolution is set to 512. Bump resolution is set to 1024. Production quality with transparency The Number Of Samples is set to 9. Color resolution is set to 512. Bump resolution is set to 1024. Allows for transparency. Number Of Samples Lets you select the exact number of samples per pixel used to control the anti-aliasing of objects during rendering. For software rendering, each pixel is sampled first in the center, then slightly off center for subsequent samples. For hardware, each pixel is sampled in the center. For subsequent samples, the image is then re-rendered slightly offset, and each pixel is sampled in the center again. The images are then aligned to produce the final image. Frame buffer format A frame buffer is the video memory that holds the pixels from which the video display (frame) is refreshed. Select the type of frame buffer you want to use from the drop-down list: ■

RGBA: 8 bytes per channel

■

RGBA: 16-bit float per channel Transparent shadow maps Turn on if you want to use transparent shadow maps.

Transparency sorting The method by which sorting is performed prior to rendering to improve transparency. Per object Transparent objects are sorted and drawn from furthest to closest in distance. This option provides faster results buy may not render complex transparent objects correctly. Per polygon Each object's polygons are sorted and drawn from furthest to closest in distance from the viewer. This option provides more accurate transparency representation but may take longer to process. Color resolution If hardware rendering cannot directly evaluate a shading network, the shading network is baked to a 2D image that the hardware renderer can use. This option specifies the dimension of the baked image for supported mapped color channels on a material. Supported channels include color, incandescence, ambient, reflected color, and transparency. The default value is 128, which means that any baked color images have dimensions 128 by 128 pixels.

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Bump resolution If hardware rendering cannot directly evaluate a shading network, the shading network is baked to a 2D image that the hardware renderer can use. This option specifies the dimension of the baked image for supported bump maps, which typically must be of a higher resolution than that used for mapped color channels. The default value for this option is 256, which means that any baked bump images have dimensions 256 by 256 pixels.

Texture compression Enable or disable this option. Disabled/Enabled Texture compression can reduce memory usage by up to 75%, and may increase draw performance. The algorithm used (DXT5) typically introduces very little compression artifacts, so it's generally appropriate for a wide range of textures.

Render Options For more information about render layers and passes, see Render layer overview on page 68 and Render passes on page 301. Shading Model

Culling Lets you control the type of culling used for rendering. Per object The Culling option is based on the per object settings found in the Render Stats section of the selected object’s Attribute Editor. The current options are: Double Sided renders double sided lighting with the current normals on the object. Single Sided renders with single sided lighting with the current normals on the object. Opposite renders with single sided lighting with the reversed normals on the object. All Double Sided Forces all objects to render using the All Double Sided option, whether or not you set that option on the object. All Single Sided offers better rendering performance than All Double Sided. All Single Sided Forces all objects to render using the All Singled Sided options whether or not you set that option on the object. If the Opposite suboption is enabled then that suboption is used. All Single Sided offers better rendering performance than All Double Sided.

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Small object culling threshold When this performance-improving option is enabled (default), opaque objects that are smaller than the specified threshold are not drawn. This option provides the same functionality as the Occlusion Culling option found in High Quality Rendering mode in scene views. Percent of image size This is the threshold suboption for the Small Object Culling option. The threshold you provide is the percentage of the image size that an object occupies in the output image. If an object is less than that percentage in size then it is not drawn. Size is measure in pixels in screen space (relative to the camera used for rendering). The default percentage is 0 percent. This option ignores View->Camera Settings options (such as Gate and Fill options), which are used for image output only. E.g. % = 10.0. Image size 100 by 100 (pixels). The threshold in pixels would be 100X100 * .10 = 1000 pixels. If an object was less than 1000 pixels in size then it would not be drawn. E.g. % = 0.0 Image size 100 by 100 (pixels). The threshold in pixels would be 100X100 * 0 = 0 pixels. If an object was less than 0 pixels in size then it would not be drawn. This can occur when one opaque object completely obscures another object with respect to the current camera used for rendering. Hardware geometry cache Turn on this setting to cache geometry to your video card, when the video card memory is not being used elsewhere. In some cases, this can improve performance. You can set the Maximum cache size (in MB) if you want to limit the usage to a particular portion of the available video card memory, up to 512 MB. Hardware Environment Lookup Select Consistent with Software to interpret the Env Ball/Env Cube map in the same way as the Maya Software renderer. Select Respects Hardware to interpret the Env Ball/Env Cube map according to the Maya Hardware Renderer. Motion blur If this option is on, you can change Motion Blur by Frame option and the Number of Exposures option. Motion blur by frame In the hardware renderer, motion blur is achieved by rendering the scene at specific points in time and blending the resulting sample renders into a single image. Blur by frame represents the absolute time range, starting from the current frame, that is blurred. This determines the approximate start and end times of the blur. This time range is then adjusted in accordance with the camera’s Camera Shutter Angle attribute in the Attribute Editor.

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Number of exposures The number of exposures divides the above time range determined by the Motion Blur by Frame option into discrete moments in time, where the entire scene is re-rendered. The final image is the accumulated average of all the exposures. So to obtain a smooth blur, a larger number of exposures is desired. Similarly, for a motion trail, a smaller number of exposures is preferable. Enable Geometry Mask For hardware rendering. When this option is turned on, opaque geometry objects mask out particle objects, and transparent geometry is not drawn. This is especially useful when compositing particles over software-rendered geometry. Blend Specular With Alpha Enable this option to avoid the specular appearing as if it is floating on top of a surface. When this option is enabled, the specular is multiplied with the alpha and the resulting highlight only appears on the opaque surface and not the transparent surface. Shadow linking You can reduce the rendering time required for your scene by linking lights with surfaces so that only the specified surfaces are included in the calculation of shadows (shadow linking) or illumination (light linking) by a given light. Use the drop-down list to select one of the three choices available with this option: ■

Shadows obey shadow linking

■

Shadows obey light linking

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Shadows ignore linking

The shadows in your scene can obey only one of light linking or shadow linking and not both. Therefore, you must decide whether to incorporate light linking or shadow linking in your scene and make your selection from the drop-down list accordingly. You can also render part of your scene using the default settings (instead of obeying the links that you have created). Select Shadows Ignore Linking so that all links that you have established or broken using shadow linking or light linking are ignored. The default is set to Shadows Obey Light Linking. See Shadow linking for more information regarding shadow linking. See Light linking for more information regarding light linking.

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Render Settings: Maya Vector tab To select a renderer to see the Maya Vector tab, see Select a renderer on page 11. Render Settings that apply to all renderers are in the Render Settings: Common tab on page 377. For information on the render settings, see Maya Vector renderer on page 8.

Image Format Options Frame Rate (SWF and SVG only) The frame rate of the Flash Player file or SVG file (measured in frames per second). Flash Version (SWF only) The version of the rendered Flash Player file: Flash 3, Flash 4, or Flash 5. The rendered Flash Player file plays back in any version of the Flash Player (and import into any version of the Flash authoring application) that is equal to or greater than the Flash Version. NOTE When Flash Version is Flash 4, and Fill Style is Area Gradient or Mesh Gradient, the rendered animation contains a dummy frame at its beginning. (This is to compensate for a limitation in the Flash 4 authoring application.) After importing your animation into the Flash 4 authoring application, delete this extra frame. Open in Browser (SWF only) Displays the vector image or animation in your default browser after it is rendered (using Render > Render Current Frame, Render > Batch Render, or mayaVectorRender). NOTE You must have the Flash browser plug-in installed on your system in order to display the rendered image or animation. Combine Fills and Edges (SWF only) When Combine Fills and Edges is on, outlines and fills for a surface are a single object. If you import the file into the Flash authoring application, you cannot separate the outlines and fills unless you break apart the object. However, the size of the rendered file is smaller than when Combine Fills and Edges is off. When Combine Fills and Edges is off, outlines and fills for a surface are separate objects. If you import the file into the Flash authoring application, you can separate the outlines and fills without breaking apart the object. However, the size of the rendered file is larger than when Combine Fills and Edges is on. Svg Animation (SVG only) If Svg Animation is Native, Maya creates one SVG file containing the frames of your animation and the scripting that drives it.

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If Svg Animation is HTML Script, Maya creates an SVG file containing the frames of your animation and an HTML file containing the JavaScript that drives it. If your animation is long (approximately 40 frames or more), file size increases when Svg Animation is Native. Compress (SVG only) Compresses the rendered SVG file, significantly reducing its file size. If you plan to publish the SVG file directly to the web, you may want to turn on Compress. If you plan to import the SVG file into another application and edit it, turn off Compress. You cannot edit a compressed SVG file.

Appearance Options Curve Tolerance A value from 0 to 15 that determines how object outlines are represented with either curved lines or a series of straight line segments. When Curve Tolerance is 0, object outlines are represented by a series of straight line segments (one segment for each polygon edge). This produces an outline that exactly matches the outline of polygons, but also produces larger file sizes. When Curve Tolerance is 15, object outlines are represented by curved lines. This produces an outline that may appear slightly distorted compared to the original object’s outline, but also produces smaller file sizes. You may need to adjust the Curve Tolerance setting on a scene by scene basis to produce the best compromise between outline accuracy and file size. Begin by setting Curve Tolerance to 7.5 (the default). If the rendered file size is too large, try increasing Curve Tolerance. If object outlines appear distorted, or the animation appears jumpy where there are curved outlines, try decreasing Curve Tolerance. NOTE Adjusting the Curve Tolerance value may have no apparent effect on file size when another setting (for example, Fill Style) is the dominant factor affecting file size. Secondary Curve Fitting Provides more control over the conversion of line segments into curves by adding a second pass. Typically this results in more linear segments converted to curves. While this option increases render time, it can help produce better results and smaller files. Detail Level Preset, Detail Level Determines the level of detail in the rendered image. A High Detail Level (30) produces a more detailed image and a more accurate render than a Low Detail Level (10), but takes longer to render and

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increases file size. (When the Detail Level is Low, small polygons are combined with adjacent polygons.) You may need to adjust the Detail Level on a scene by scene basis to produce the best compromise between image quality and file size. Begin by setting Detail Level to Low, and increase it as necessary to produce acceptable image quality. Set Detail Level to Automatic to allow Maya to choose the appropriate level of detail for your scene. Set Detail Level to Custom and use the numeric field or slider to set the Detail Level to any value between 1 and 50. (Setting Detail Level to 0 is the same as choosing the Automatic preset.) NOTE ■

Doubling the Detail Level value produces twice as much detail in the rendered image.

■

Setting Detail Level less than 4 is not recommended.

Fill Options Fill Objects Surfaces are shaded based on the Fill Style. To render surfaces as unfilled outlines, turn off Fill Objects and turn on Include Edges. Fill Style The style of shading used to fill surfaces in the rendered image. For all fill styles (except Single Color) the fill color is based on surface material color and lighting from point lights only; all other types of lights are ignored. If your scene does not contain point lights, a default point light (located at the camera) is automatically created during rendering (and removed after rendering). NOTE Surface fills are re-calculated for each frame and may appear to change, shift or jump during an animation. Single Color Fills each surface with one solid color based on the surface material color.

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Single Color can produce nice cartoon-like results, especially when your model is composed of separate surfaces that each have a different colored material. NOTE The Single Color fill color is actually based on the surface material color and an ambient light (located at the camera) that is automatically created during rendering (and removed after rendering). Therefore, the fill color may not exactly match the surface material color. The fill color should not change during an animation. TIP For better definition of surface edges, turn on Edges. Two Color Fills each surface with two solid colors based on the surface material color and on scene lighting.

Two Color produces results that look slightly more 3D than Single Color, but also produces larger file sizes. TIP For geometric objects that consist of many flat planes (for example, a cube), Two Color may produce unnatural looking results (that is, each flat surface is filled with two solid colors). For such objects Average Color is usually more appropriate. Four Color Fills each surface with four solid colors based on the surface material color and on scene lighting.

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Four Color produces results that look even more 3D than Two Color or Single Color, but also produces much larger file sizes. TIP For geometric objects that consist of many flat planes (for example, a cube), Four Color may produce unnatural looking results (that is, each flat surface is filled with four solid colors). For such objects Average Color is usually more appropriate. Full Color Fills each polygon on a surface with one solid color based on the surface material color and on scene lighting.

Full Color produces realistic 3D results, but also produces very large file sizes. (The greater the number of polygons in your model, the greater the file size.) TIP If you want to produce a high level of detail, and file size is not an issue, Mesh Gradient usually produces better results than Full Color. NOTE Full Color is the highest quality fill style available when rendering to AI and EPS formats. Average Color Fills each surface with one solid color based on the surface material color and on scene lighting.

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TIP For objects that are divided into surfaces with hard edges, Average Color often produces the best combination of 3D effect and modest file size, especially when the object is animated. For smooth, organic objects that have few surfaces defined by hard edges, Average Color does not usually produce results that are any better than Single Color. Area Gradient (SWF and SVG only) Fills each surface with one radial gradient based on the surface material color and on scene lighting.

Area Gradient can produce nice 3D effects with a small increase in file size. TIP ■

For scenes that contain faceted objects (objects composed of many distinctly defined surfaces), Area Gradient produces very good results.

■

For scenes that contain a combination of flat and smooth surfaces, Area Gradient produces a nice balance of fills. The smooth surfaces are filled with gradients, and the flat surfaces are filled with a more even color.

■

For scenes that contain only smooth surfaces, Area Gradient may produce an overwhelming number of gradient fills.

NOTE This option is only available when File Format is SWF or SVG. Mesh Gradient (SWF and SVG only) Fills each polygon on a surface with a linear gradient based on the surface material color and on scene lighting.

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Mesh Gradient produces very realistic 3D results, but also produces very large file sizes. (The greater the number of polygons in your model, the greater the file size.) Mesh Gradient is the highest quality fill style available when rendering to SWF and SVG formats. NOTE In certain rare situations shading may be incorrect when Fill Style is Mesh Gradient. For example, a plane having a ramp texture applied to it may render with an area of solid color. Try adjusting the texture very slightly and re-rendering. Show Back Faces Surfaces with normals facing away from the camera are rendered as if they were facing the camera. When Show Back Faces is off, surfaces with normals facing away from the camera are not rendered. NOTE Surfaces with normals facing away from the camera may not be visible, even if Show Back Faces is on, if another surface is between it and the camera. TIP Turning off Show Back Faces may decrease rendering times and file size. Shadows (SWF and bitmap formats only) Object shadows are rendered (based only on shadow-casting point lights in your scene). Shadows can greatly enhance the 3D effect. However, shadows also increase file size and significantly increase render time.

When Shadows is turned on, shadows are rendered for all objects. You cannot render shadows only on certain objects (for example, by turning off Casts Shadows or Receive Shadows for an object). Shadows are only rendered if there is a shadow-casting point light in your scene (that is, a point light that has Use Depth Map Shadows or Use Ray Trace Shadows turned on). NOTE ■

You cannot set the shadow color.

■

Shadows are not cast onto surfaces with transparent materials.

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Highlights (SWF and bitmap formats only) Specular highlights are rendered (based only on point lights in your scene and on surface material shininess). (When Fill Style is Single Color, specular highlights are based on the position of point lights in your scene. Changing the intensity or color of point lights does not change the appearance of highlights.)

Regions of surfaces that are close to being perpendicular to a point light are filled with a number of concentric solid color regions (based on surface material Specular Color and on the Highlight Level value) that are lighter than the rest of the surface. For this material...

Surface shininess is based only on...

Anisotropic

Roughness

Blinn

Eccentricity

Phong

Cosine Power

Phong E

Roughness

NOTE ■

This option is only available when Fill Style is Single Color, Average Color or Area Gradient.

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Highlights are only rendered if there is a point light in your scene that has Emit Specular turned on.

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If a surface material’s Specular Color is mapped with a texture, the color of the highlight is based on the texture’s Default Color. If a surface material’s Specular Color is mapped with a utility node, the color of the highlight is white.

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Highlight Level (SWF and bitmap formats only) The number of concentric solid color regions used to represent specular highlights. The valid range is 1 to 8. The default value is 4.

NOTE This option is only available when Highlights is on. Reflections (SWF and bitmap formats only) Surface reflections are rendered (based on the surface material Reflectivity).

Reflection Depth (SWF and bitmap formats only) The maximum number of times a surface can inter-reflect with other surfaces. The valid range is 1 to 4. The default value is 2. NOTE This option is only available when Reflections is on.

Edge Options Include Edges Surface edges and silhouettes are rendered as outlines.

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TIP To render surfaces as unfilled outlines, turn off Fill Objects and turn on Include Edges. Edge Weight Preset, Edge Weight The thickness of surface outlines (measured in points).

NOTE When File Format is SWF, changes in Edge Weight less than 1 Point are not noticeable unless you zoom into the outline. Edge Style When Edge Style is Outlines, surface edges and silhouettes are rendered as outlines. (Use Detail Edges to also render sharp polygon edges as outlines.)

When Edge Style is Entire Mesh, all polygon edges are rendered as outlines. Entire Mesh produces very large file sizes. (The greater the number of polygons in your model, the greater the file size.) Edge Color The color of surface outlines.

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Hidden Edges Surface edges that are behind another surface are visible in the rendered image. (This may make certain objects look transparent or make models appear as wireframes.)

Hidden Edges increases rendered file size because of the extra vector information. TIP If you are rendering a model with many polygons, avoid turning on Hidden Edges and setting Edge Style to Entire Mesh; too many lines will likely appear in the rendered image. Edge Detail Sharp edges between polygons are rendered as outlines. The Min Edge Angle controls which polygon edges are rendered as outlines. Edge Detail can help define the shape of a 3D object, especially when the object is composed of few surfaces, but also produces larger file sizes.

NOTE This option is only available when Edge Style is Outlines. Outlines at Intersections When you turn this attribute on, an outline appears along the point where two objects intersect. Use the Edge Priority setting to resolve edge outline conflicts (when depth does not automatically do so). This attribute is also located in the Render Settings, Maya Vector tab, in the Edge Options section. Min Edge Angle Determines which polygon edges are rendered as outlines when Edge Detail is on. Min Edge Angle is the minimum angle (measured in

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degrees) that two adjacent polygons’ normals must have in order for their common edge to be rendered as an outline. Decreasing the Min Edge Angle produces larger file sizes because of the extra vector information in the rendered file. NOTE This option is only available when Edge Style is Outlines.

Render Optimizations The Render Optimization setting specifies how the Vector renderer optimizes the current frame to reduce file sizes. You can select one of the following types of optimizations: Safe Removes redundant geometry in areas of high detail, especially geometry that is only visible by zooming in on the area. Redundant edges occur on the at the intersection of the visible and invisible areas of the scene, and are always safe to remove. Good Removes redundant geometry in areas of high detail, and removes sub-pixel geometry that is not visible unless zooming into a high detail area. Aggressive Removes redundant geometry, sub-pixel geometry, and geometry that is slightly above the single pixel level, in high detail areas. This setting reduces file size by up to 30%. NOTE Using Aggressive optimization makes it possible to visibly detect the missing geometry without zooming in on the area. It may also result in inconsistent geometry (like unclosed shapes).

Create Render Passes window

You can access the Create Render Passes window by selecting mental ray as

your renderer, then selecting the Passes tab, and clicking the New Pass button. Pass List Select, from the list, the render passes that you want to create. You can multi-select render passes by shift-clicking or control-clicking. All render pass presets that you have created are also available from this list.

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Name Presets Pass Prefix / Pass Suffix Add a prefix or suffix to the render pass names of the passes that you are creating. Create Pass Set / Pass Set Name Select the Create Pass Set option to create a new pass set. All render passes that you created simultaneously with the render pass set are automatically associated with the set. Create and Close / Create Click the Create and Close button to create the selected render passes and close the Create Render Passes window. Click the Create button to keep the Create Render Passes window open and create multiple versions of the selected passes.

Custom Stereo Rig Editor

The Custom Stereo Editor is used when you want to create a custom stereocopic camera rig with MEL or Python scripting. Modifying existing rigs - displays all the editable rigs you’ve created in the scene. Registering a new rig - creates a new rig for the scene. Enter in the Custom Rig Name, select the type of Language used: MEL/Python from the drop down menu and the enter the procedure you want to occur for the rig. Click Add New Rig to create the new rig.

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Render View Window > Rendering Editors > Render View In scene view: Panels > Panel > Render View

Render View menu bar You can access the following items from pop-up menus by right-clicking in the panel. Some menu items are renderer-specific. For example, IPR menu items do not appear for Maya hardware rendering. For more information on Render View, see Render View rendering on page 52.

File menu Open Image Loads one image from disk into Render View. Images usually end with suffixes indicating their image format. Save Image Saves the image to disk in the /images directory (as specified by your current project management settings). Open IPR File Opens the file browser to the iprImages directory from where you can open a saved IPR file into Render View. NOTE Make sure the IPR file you load corresponds to the current scene file. If the name of a surface in the IPR file does not match a corresponding surface in the current scene, you are unable to adjust the shading characteristics of that surface. Save IPR File Saves the current IPR file to the iprImages directory. Close IPR File Closes the IPR file on which you are working and ends the current IPR session. Load Render Pass

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Use this option to preview your multi-render pass output. Select the desired render pass output from the submenu. Render Diagnostics The Script Editor window appears providing you with valuable information about how to improve performance or avoid certain limitations. You can run the diagnostics while experimenting with different settings, or before you start final rendering. Keep Image in Render View Keeps the current image so you can view it later and compare it against newly rendered images. When you keep more than one image, a slider displays at the bottom of the window letting you bring a specific image into view without loading the image. The images are lost when you end your Maya session. Remove Image from Render View Dismisses the current image (and the memory needed by it) from Render View. Select the image that you want to remove using the slider. Remove All Images from Render View Dismisses all images (and the memory these images need) from Render View so that only the most recently rendered image remains. If you are viewing one of the saved images in the Render View window, this option still removes all saved images, including the currently displayed image.

View menu Frame Image Frames the image you are rendering to fit Render View. Frame Region Frames the region you marquee to fit Render View. Real Size Automatically adjusts the view so the zoom factor is 1.0, and each pixel of the image occupies one pixel on the display. Show Region Marquee Displays the red render region marquee. Reset Region Marquee Resets the render region marquee to surround the entire image. Grab Swatch to Hypershade/ Visor Use to customize Hypershade swatches. A customized swatch lets you quickly access a scene and all its associated attributes.

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Render menu Redo Previous Render Renders the same view you last rendered. If you rendered a region the last time, Redo Previous Render renders the entire image. Render Region When you draw a marquee around an area in Render View, select this option to render only that area. This is useful if you’ve made a change to part of the surface on which you want to perform a quick test render.

Render All Layers Toggle to render all layers or only the selected layer.

Render All Layers > Renders all the layers in the scene based on the options set in the Render All Layers Options window. Composite Layers Renders a composited result of all layers is shown in the Render View. This is the default for Render All Layers. Composite and Keep Layers Renders all your layers as individual images, but displays a composited result. Keep Layers Renders all your layers as individual images. Render Selected Objects Only Allows you to render only specified objects. Select the objects that you wish to render and choose this option. This was formerly the "Renderable Objects" option in the Common tab of the Render Settings window. Render

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Opens a menu from which you can choose the view to render, for example, persp, front, side, top or any of your stereo cameras. Snapshot Does not work when IPR rendering. Opens a menu from which you can choose the view. A wireframe snapshot is taken of the view you select and loaded as a background into Render View. You can then marquee a region to render in front of the snapshot’s background and select the Render Region icon. TIP Zoom into the view you select if you want to see the results up close.

IPR menu For Maya software and mental ray rendering only. For details on IPR, see Interactive Photorealistic Rendering (IPR) on page 47. Redo Previous IPR Render IPR renders the same view last IPR rendered. IPR Render Opens a menu, from which you can choose the view to IPR render. Update Shadow Maps Regenerates shadow maps and updates the IPR image. You cannot interactively adjust shadow maps. Update Image Planes/Background Updates the marquee IPR region with any changes you make to the image plane. If you don’t select this option after you make changes to an image plane, the effects of the changes are not visible in IPR until you either perform a new IPR render or marquee a new tuning region. Refresh IPR Image Completely updates (re-shades) the entire image based on all changes you have made. The refresh occurs a bit at a time because loading all samples for the entire image often uses too much memory.

IPR Quality Selects quality settings for the IPR. Preview If selected, a good balance between quality and time is achieved. Preview Raytrace If selected, the IPR quality is slightly better than the IPR quality in the Preview setting due to Raytracing. Render Settings If selected, the quality presets specified in the Render Settings Window are used.

IPR Tuning Options Specifies what characteristics of the scene update interactively as you adjust. These options are related to the IPR Options in the Render Settings window.

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For example, if you turn off Render Shading, Lighting, and Glow in Render Settings window on page 376, you cannot adjust them. Update Shading and Lighting If on, the IPR image updates whenever you adjust an attribute for shading networks, lights, or when you make shading group assignments or move lights. Update Shader Glow If on, the IPR image updates whenever you adjust a shader glow (post-process) attribute. Update Light Glow If on, the IPR image updates whenever you adjust lighting or light glow attributes, or move a light. Update 2D Motion Blur If on, the IPR image updates whenever you adjust 2D motion blur attributes. Modifying the scene’s animation (for example, to make an object move faster and increase the blur) does not affect the IPR image’s motion blur because modifying the animation changes the information that was generated during the initial IPR render (motion vectors are changed), which is a change to the visibility calculation. You have to perform a new IPR render to see the results. Pause IPR Tuning Pauses the updating of the selected IPR region in the Render View.

Options menu Some menu items are renderer specific. For example, the Ignore Shadows menu item does not appear for Maya hardware rendering. Render Settings Opens the Render Settings window on page 376 when test-rendering (not IPR). Render using Select the type of renderer you use to render the image: Maya Software, Maya Hardware, Maya Vector, mental ray. Test Resolution Select the resolution at which you want to render the image. Use a reduced resolution to test render the scene if possible. See also Test render a low-res still or frame on page 127 or Test render a low-res animation on page 128 Auto Resize Allows Render View to resize the image each time you render. When on, always displays the rendered image in the center of Render View, and at real size if the image fits (one to one pixel matching). When off, the image always displays in the same place according to the last view. Auto Render Region When on, renders the image as soon as you finish dragging a marquee in Render View. This can make rendering a region a

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one-step process: drag a render region, and when you release the mouse button the region is immediately rendered. Ignore Shadows Tells Maya not to test render any shadows in the scene. This can speed up test rendering. Ignore Glows Tells Maya not to test render any glows in the scene. This can speed up test rendering.

Display menu Red Channel, Green Channel, Blue Channel Displays the red, green, or blue channels only. All Channels Displays RGB channels. Luminance Displays a weighted average of R, G, and B planes that define the luminance level of the image. Alpha Channel Displays the alpha channel only. Stereo Display

After you have rendered your scene using the stereo camera (by selecting Render > Render > stereoRig), you can view your render output in different stereo modes such as Anaglyph and Freeview (Parallel), or, from only the left or right camera. For more information regarding the stereo modes, see Stereo on page 358.

Render Info Select the type(s) of render information you want displayed in the Render View. Frame Number Displays the frame number of the image. Render Time Displays the time it took to render the image, for example 0:05 (five seconds). Camera Name Displays the name of the camera used to render the image. Layer Name If the scene has render layers, the name of the layer used in the image is displayed.

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Custom Comment Add custom text to your rendered image. When the Custom Comment dialog box appears, enter your text into the field, and click OK. Custom comments appear at the bottom of the image. Dithered Turn off Dithered to display the best version of a image. Turn on Dithered to display a dithered image (does not flicker when displayed). Dithered is on by default. Toolbar Shows/hides the Render View toolbar. Toolbar is on by default.

Render View toolbar You can use the rendering buttons in the Status Line in Maya’s main window, or use the buttons in the Render View toolbar to perform various operations. Some tools are renderer specific. For example, the IPR tools appear only for Maya software and mental ray rendering. For more information on Render View, see Render View rendering on page 52. Redo Previous Render

Renders the same view you rendered last. If you rendered a region the last time, Redo Previous Render renders the entire image. Right-click this button to select a camera. All cameras, default and user-defined, are available. Render Region

Renders only the region with a marquee. This is useful if you’ve made a change to part of the surface on which you want to perform a quick test render. See Render a region of your scene on page 130 for details. Snapshot

Opens a menu from which you can choose the view. A wireframe snapshot is taken of the view you select and loaded as a background into Render View.

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You can then marquee a region to render in front of the snapshot’s background and select the Render region icon. Right-click this button to select a camera. All cameras, default and user-defined, are available. NOTE This option does not work when IPR rendering. Redo Previous IPR Render

IPR renders the same view last IPR rendered. Right-click this button to select a camera. All cameras, default and user-defined, are available. Refresh the IPR Image

Completely updates the entire image based on all changes you have made. The refresh occurs a bit at a time—loading all the samples for the entire image may use large amounts of memory. Open Render Settings Window

Opens the Render Settings window on page 376. Display RGB Channels

Displays the image with RGB channels. This is the default display mode. Right-click this button to select individual channels. Each channel has a corresponding icon: Channel

Icon

RGB Channels

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Channel

Icon

Red

Green

Blue

Luminance

Display Alpha Channel

Displays the image’s alpha channel only. See Use Background and Matte Opacity for a few examples of how the alpha channel is used. Display Real Size

Displays the image at its exact pixel resolution. See also Test render a low-res still or frame on page 127. Keep Image

Keeps the current image so you can view it later. When you keep more than one image, a slider displays at the bottom of the window. Drag this slider to view a previously “kept” image.

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You can also keep rendered images with any annotation you’ve added. Right-click the Keep Image button, and select the Keep Image with Comment option. When the Custom Comment dialog box appears, enter your text into the field, and click OK. Custom comments appear at the bottom of the image. NOTE The stored (“kept”) images are lost when you end your Maya session.

Remove Current Image / Remove All Images

Right-click the icon to select either the Remove Current Image or Remove All Images option. These options can also be selected via the File > Remove Image from Render View and File > Remove All Images from Render View menus in the Render View window. See Render View menu bar on page 472 for more information. Remove Current Image Releases the current image (and the memory it uses) from Render View. Select the image you want to remove using the slider at the bottom of the window. Remove All Images Releases all images (and the memory these images use) from Render View so that only the most recently rendered image remains. If you are viewing one of the saved images in the Render View window, this option still removes all saved images, including the currently displayed image. Only the most recently rendered image is kept. TIP Only “kept” images can be removed. If you are viewing a newly rendered image in the Render View window that has not been kept, selecting this option will display an error message that the current image cannot be removed. Show Render Diagnostics in the Script Editor

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Click the icon after you adjust objects, and before you re-render. The Script Editor that displays provides valuable information about how you can improve performance. You can run the diagnostics while experimenting with rendering settings, or before you start the final render. Renderer Select a renderer from the drop-down list: Maya Software, Maya Hardware, Maya Vector, mental ray and any additional 3rd party renderers you have installed. Pause IPR Tuning

Pauses the updating of the selected IPR region in the Render View. Close IPR File and Stop Tuning

Closes the current IPR file and ends the current IPR session.

Rendering Flags Rendering Flags window Window > Rendering Editors > Rendering Flags The Rendering Flags window lets you list the elements in your scene and provides you with a way to set the attributes for the nodes you select.

Rendering Flags Show list Click the down arrow to display the Show menu, then select an item or items for which you want a list of attributes. The attributes for these items are listed in the right panel where you can change and set them, much like in the Channel Box.

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Rendering Flags window panels The Rendering Flags window contains two panels. The left panel lists the items you select from the Show menu, and the right panel lists the attributes for the selected items. In the left panel, click the list item for which you want to change or set the attributes and the details display in the right panel.

To set attributes for multiple nodes in the Rendering Flags window 1 You can change or set attributes for several related objects by selecting them in the left panel, and setting the attribute value in the right panel. For example, if you want to turn the visibility off for two NURBS spheres in the scene, select both spheres from the left panel and type off beside Visibility in the right panel.

Once you change an attribute for a selected item, the heading changes color in the list reminding you of the change.

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Hardware Render Buffer Hardware Render Buffer window Window > Rendering Editors > Hardware Render Buffer NOTE The Hardware renderer, with its greater capabilities, is now recommended to perform hardware rendering. See Maya Hardware renderer on page 5. The Hardware Render Buffer lets you render an animation using your computer’s display graphics card. Hardware rendering is much faster than software rendering, although the result may be of lower quality. You can use the Hardware Render Buffer to preview animations, or to render specific types of particle effects. Render Sequence will not render particles successfully if the Render Passes and “Motion Blur” options (found in the Multi-Pass Render Options section of the Hardware Render Buffer Attribute section) are equivalent integers. For example, if Render Passes is set to 3 and Motion Blur is set to 3, hardware particle rendering will not work. Set them to non-equivalent values or to use the Disk Cache option (Solvers > Create Particle Disk Cache). NOTE When the overscan attribute of the camera is anything other than 1.0, image planes are positioned incorrectly in the hardware render buffer (as can be seen compared to the correct placement in software rendering). To work around this limitation, temporarily set the overscan to 1.0 when hardware buffer rendering. To open the Hardware Render Buffer 1 Select Window > Rendering Editors > Hardware Render Buffer. NOTE On Mac OS X, the Hardware Render Buffer does not open in a panel; the panel is blank when you select it.

To set options for the Hardware Render Buffer 1 In the Hardware Render Buffer, click Render > Attributes. For a description of the options, see Hardware Render Buffer menus on page 491.

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IMPORTANT The Hardware Render Buffer renders images based on your monitor’s display (using screen captures). Before rendering from the Hardware Render Buffer, make sure the Hardware Render Buffer fits on your monitor, make sure no other window overlaps the Hardware Render Buffer, and disable your computer’s screen saver.

To determine hardware rendering quality 1 In the Shading menu in the view panel, make sure Smooth Shade All and Hardware Texturing are selected. 2 In Hypershade, double-click the material swatch you want to preview to open its Attribute Editor. 3 In the Hardware Texturing section of the material’s Attribute Editor, the Textured channel menu contains the attributes you can hardware render. Select the Textured channel you want to view from the menu.

NOTE ■

You can only view one channel at a time.

■

To view an attribute, it must be mapped to a texture. Attributes that are not mapped are dimmed.

■

Some channels, such as Bump Map, do not provide hardware textured results. You must use Render View to see the results.

4 Select the resolution you want from the Texture resolution menu.

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Use the flipbook (Linux and Windows only) The Flipbook lets you play back a rendered sequence of images. The sequence is displayed using the fcheck utility. To play back a rendered sequence of images 1 Select the sequence from the Flipbooks menu. The sequence is displayed using the Fcheck utility.

Hardware Render Buffer global settings Window > Rendering Editors > Hardware Render Buffer (in Hardware Render Buffer window) Render > Attributes.

Image Output Files Filename The base name for all hardware rendered image files. The default file name is im. Extension The format of the extension(s) added to the base name for all rendered image files. Options with ext include the Image Format in the extension. The default setting is name.001. Start Frame, End Frame The first and last frame to render. The default value for Start Frame is 1. The default value for End Frame is 10.

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By Frame The increment between frames you want to render. For instance, if By Frame is set to 1, the Hardware Render Buffer renders frames 1, 2, 3, and so on. If set to 2, it renders 1, 3, 5, and so on. The default value is 1. Image Format The format for saving hardware rendered image files. The default setting is Maya IFF. Resolution The resolution of hardware rendered image files. Click the Select button to select a preset image resolution. Alpha Source The type of alpha information saved with the hardware rendered images. Alpha information represents the opacity of each pixel, and is used for compositing images using compositor software. (Alpha information is also referred to as alpha channel, mask, matte, or alpha buffer.) If you do not plan to composite hardware rendered images, set Alpha Source Off. The default setting is Off. Write ZDepth If Write ZDepth is on, the hardware rendered contains depth information (the distance of objects from the camera). Write ZDepth is off by default. TIP Depth information is sometimes necessary when compositing images (for example, compositing hardware rendered particles that pass behind a software rendered transparent object). If you do not plan to composite hardware rendered images, or do not require depth information for compositing, turn off Write ZDepth.

Alpha Source table Off

Alpha information is not included in hardware rendered images.

Hardware Alpha

Assigns each pixel an alpha value based on its opacity, regardless of its brightness or color. The more opaque a pixel is, the more opaque it appears in the image’s alpha channel.Setting Alpha Source to Hardware Alpha only has an effect if your computer has a hardware alpha buffer. If it does not have a hardware alpha buffer and you set Alpha Source to Hardware Alpha, the alpha channel of hardware rendered images is fully opaque.

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Luminance

Assigns each pixel an alpha value based on its brightness. The brighter a pixel is, the more opaque it appears in the image’s alpha channel.

Red Channel

Assigns each pixel an alpha value equal to the value of its RGB red component. The higher a pixel’s red value is, the more opaque it appears in the image’s alpha channel.

Green Channel

Assigns each pixel an alpha value equal to the value of its RGB green component. The higher a pixel’s green value is, the more opaque it appears in the image’s alpha channel.

Blue Channel

Assigns each pixel an alpha value equal to the value of its RGB blue component. The higher a pixel’s blue value is, the more opaque it appears in the image’s alpha channel.

Clamp

Assigns each rendered pixel an alpha value of 1 (fully opaque), and each unrendered pixel an alpha value of 0 (fully transparent).

Inverse Clamp

Assigns each rendered pixel an alpha value of 0 (fully transparent), and each unrendered pixel an alpha value of 1 (fully opaque).

Render Modes Lighting Mode Controls how objects are lit during hardware rendering. The default setting is Default Light. Default Light A default directional light illuminates the scene in the direction that the camera faces.

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All Lights The lights in the scene (up to a maximum of eight lights) illuminate the scene. Selected Lights The lights in the scene that you’ve selected (for example, in the Outliner) illuminate the scene.

Draw Style Controls how objects are hardware rendered. (If Geometry Mask is on, Draw Style has no effect.) The default setting is Smooth Shaded. Points NURBS surfaces are rendered as points evenly spaced along surface, polygonal surfaces are rendered as points (corresponding to vertices), and particles are rendered as points. Wireframe Surfaces are rendered in wireframe. Flat Shaded Surfaces are rendered as flat shaded polygons. Smooth Shaded Surfaces are rendered as smooth shaded polygons using a Phong material. Texturing If on, textures are hardware rendered. Texturing is on by default. Line Smoothing If on, sharp, jagged edges on surfaces and streaks on Streak or MultiStreak particles are softened. Line Smoothing is off by default. Full Image Resolution If on and Resolution is greater than the monitor’s resolution (the hardware rendered images cannot fit on the screen), the Hardware Render Buffer divides the image into tiles, renders each tile separately, then assembles the tiles together when it saves the image to disk. If you are rendering an animation, the Hardware Render Buffer displays each tile as it renders it. If off and Resolution is greater than the monitor’s resolution, the Hardware Render Buffer only renders the part of the image displayed on the monitor. Geometry Mask When off, surfaces are hardware rendered. When on, Maya masks out all geometry by setting the mask values to 0. Pixels of the rendered image belonging to any geometry have a zero opacity in the image’s alpha channel. Geometry Mask is off by default. Display Shadows Turn this on to display shadows from directional and spot lights for geometry (NURBS, polygons, subdivision surfaces) and particles (points, multipoints, and spheres only). This is available only when All Lights or Selected Lights are specified in the Lighting Mode drop-down list.

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NOTE These hardware shadows can be calculated and displayed on graphics cards with drivers that support the ARB_multitexture and EXT_texture_env_combine OpenGL extensions (such as graphic cards with Nvidia®GeForce®or Quadro GPU, or ATI Radeon 8800).

Multi-Pass Render Options Multi Pass Rendering If off, the Hardware Render Buffer renders each frame using one pass. If on, the Hardware Render Buffer renders each frame using more than one pass (based on the Render Passes setting, next). This softens or blurs particles with a MultiStreak or MultiPoint Render Type. Multi Pass Rendering is off by default. Render Passes The number of passes the Hardware Render Buffer uses to render each frame. The more passes per frame, the greater the softening or blurring of particles with a MultiStreak or MultiPoint Render Type (and a longer rendering time). Render Passes is only available if Multi Pass Rendering is on. The default setting is 3. TIP If the Motion Blur value is greater than 0, set the Render Passes value to at least the Motion Blur value minus 1. For example, if the Motion Blur value is 4, set the Render Passes value to at least 3. Anti-Alias Polygons If on, sharp, jagged surface edges are softened (anti-aliased) during hardware rendering. This option only works if Multi Pass Rendering is on and the computer hardware supports anti-aliasing. Anti-Alias Polygons is off by default. Edge Smoothing Controls how much sharp, jagged surface edges are softened (anti-aliased) during hardware rendering when Anti-Alias Polygons is on. The higher the value, the softer the edges. Set Edge Smoothing to 1 for clear, smooth edges. If Edge Smoothing is too large (for example, 5), surface edges are excessively blurred. An Edge Smoothing value of 0 has the same effect as turning off Anti-Alias Polygons. The default value is 1. Motion Blur Controls how much objects are motion blurred. The higher the Motion Blur value, the greater the motion blur effect. A Motion Blur value of 0 means no motion blur. A value of 0.5 means the shutter is open for half the frame duration. The default value is 0. TIP If the Motion Blur value is greater than 0, set the Render Passes value to at least the Motion Blur value minus 1. (For example, if the Motion Blur value is 4, set the Render Passes value to at least 3.)

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Display Options Controls which icons are hardware rendered, and the background color for hardware rendered images. Grid If on, the grid is hardware rendered. Grid is off by default. Camera Icons If on, any camera icons visible in the Hardware Render Buffer are rendered. Camera Icons is off by default. Light Icons If on, any light icons visible in the Hardware Render Buffer are rendered. Light Icons is off by default. Emitter Icons If on, any emitter icons visible in the Hardware Render Buffer are rendered. Emitter Icons is off by default. Field Icons If on, any field icons visible in the Hardware Render Buffer are rendered. Field Icons is off by default. Collision Icons If on, any collision icons visible in the Hardware Render Buffer are rendered. Collision Icons is off by default. Transform Icons If on, any transform icons (from the translate, rotate, or scale tools) visible in the Hardware Render Buffer are rendered. Transform Icons is off by default. Background Color The background color for hardware rendered images. The default color is black. TIP If you plan to composite hardware rendered images, set the Background Color to black.

Hardware Render Buffer menus File menu Contains the Close option. Either click the box at the top right of the window or select this option to close the Hardware Render Buffer window.

Render menu Contains options for setting rendering attributes, rendering a frame or sequence of frames, and controlling the display of the Hardware Render Buffer. Attributes Opens the Attribute Editor and displays Hardware Render Buffer Render Settings. For details, see Hardware Render Buffer window on page 484.

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Test Render Test-renders the current frame in the Hardware Render Buffer.

Render Sequence Select to render the current animation. Scale Buffer Scales the size of the Hardware Render Buffer so the rendered image is 100%, 70%, 50%, 30%, or 10% of the Resolution. TIP ■

Set Scale Buffer to 100% for the final render.

■

Scaling down the size of the rendered image decreases the amount of rendering time required and increases the speed of playback.

■

A dimmed Scale Buffer option (percentage) means that the rendered image would either be too large to display on the screen, or too small to see adequately.

Time Slider Displays the time slider and transport controls at the bottom of the Hardware Render Buffer. Click to turn the Time Slider at the bottom of the window on or off. TIP In the Hardware Render Buffer window, Render > Attributes... window, unsupported image file formats appear in the Image Format drop-down list. The following are the supported image file formats: Tiff, Tiff16, SGI, MayaIFF, JPEG, Maya16IFF, Targa, Windows Bitmap, MacPaint, Photoshop, PNG, QuickDraw, and Quick Time Image. When you select another (unsupported) format from the drop-down list, Maya renders the image as an .iff file.

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Cameras menu The view in the Hardware Render Buffer is actually a copy of the corresponding camera view. For example, if the camera view displays the resolution gate, the Hardware Render Buffer view also displays the resolution gate. The Cameras menu contains a list of all cameras in the scene. Select a camera view by selecting it from the Cameras menu. For example, if you select camera 1, the Hardware Render Buffer displays the view as seen from the camera. If side, it displays the side view.

You can select and move objects in the Hardware Render Buffer view just as you would in a regular view. You can also adjust the camera in the Hardware Render Buffer using the Alt (Linux and Windows) or Option (Mac OS X) key and the left, middle or right mouse buttons. When you playback an animation in the Hardware Render Buffer, it also plays back in the corresponding view. To make an animation play back only in the Hardware Render Buffer, click anywhere in the Hardware Render Buffer view while the animation is playing. IMPORTANT Make sure nothing on the screen covers any part of the Hardware Render Buffer during rendering. (Hardware rendering uses screen captures to create rendered frames.)

Flipbooks menu The Flipbooks menu contains the list of sequences you rendered in the Hardware Render Buffer (if you selected Render Sequence from the Render menu) as well as the Clear Flipbook Menu option and Flipbook Flags.

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The Flipbooks Options control how sequences of images rendered from the Hardware Render Buffer display and displays the Flipbook Options window.

Flipbook Options These options control how sequences of images rendered from the Hardware Render Buffer are displayed.

Options Enter fcheck options to be used when playing back a hardware rendered sequence of images (by selecting the sequence from the Flipbooks menu of the Hardware Render Buffer). Clear Flipbook Menu Removes any rendered sequences of images from the Flipbooks menu. Flipbook Flags Displays the Flipbook Options window. This option in available for only Linux and Windows. See also “fcheck” in the Rendering Utilities online documentation for information on fcheck options.

Time slider and transport controls The time slider and transport controls in the Hardware Render Buffer are similar to the time slider and transport controls in the main Maya window.

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See the Animate > Create Animated Sweep in the Animation guide for details about the Time Slider.

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11

Render Layer attributes Render Layer render attributes Render Layer Options Find this section in each render layer’s Attribute Editor. Right-click the desired layer and select Attributes from the right-mouse menu to display the render layer’s Attribute Editor. Renderable Determines whether the select layer is renderable. When a layer is rendered, it is processed into a final image or image sequence. Global Converts the selected layer into a Global layer. A Global layer is a render layer that does not have membership. Instead it contains all the objects in the scene. By converting a layer into Global, all the objects in your scene automatically appears in the layer. A sample application of this attribute is if you have created a model and wanted to test different colors for the model. For example, if you have modeled a car, and wanted to test out different colors of paint, you can create five global layers, and in the Attribute Editor for the shader, override the color attribute for each paint color and then batch render all layers. Number Render layer index number. Use this attribute to merge layers when importing files with render layers. You can choose to merge by layer name or layer number. Set your layer number in this field. You can also merge layers when importing files with display layers. See Display Layer editor in the Basics guide for more information.

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Member Overrides Casts Shadows Turns on the shadow casting ability of the surface. To make shadows render faster, for surfaces that do not need to cast shadows, turn off Casts Shadows. Consider the following: ■

If you want the object’s shadow to render—the shadow the object casts onto other objects—make sure Casts Shadows is on.

■

If you do not want the object’s shadow to render—the shadow the object casts onto other objects—turn Casts Shadows off. NOTE ■

If you render shadows separately, use the mask channel of the rendered shadow image in your compositing software to reduce the brightness of another image.

■

When you render from the Render View window, you can render only the selected objects by selecting Render>Render Selected Objects Only.

Receive Shadows Turns on the shadow-catching ability of the surface. Motion Blur Turns on motion blur for the surface. You must also turn on Motion Blur in the Render Settings window on page 376. Primary Visibility When on, the surface is visible in the view and renders. TIP A surface’s shadow renders, however, if its Primary Visibility is off and Cast Shadows is on. This also applies to reflections and refractions. Smooth shading If this is on, each vertex uses its own normal vector - meaning smoother transition between two faces. If this is off, one normal vector is used for a face; 3 vertices in a triangle uses a same normal vector, resulting flat looking shading. Visible In Refractions When on, the surface refracts in transparent surfaces. This is supported by mental ray for Maya. Visible In Reflections

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When on, the surface reflects in reflective surfaces. This is supported by mental ray for Maya. Double Sided Determines if the surface is double-sided. If single-sided, you can decrease memory use and use the Opposite option. Opposite Opposite flips the surface normals. Double-Sided must be off to set Opposite. Depth Jitter If you set Volume Sample Override on, you can turn on Depth Jitter option. Randomizes the samples of the volume with depth which replaces banding artifacts in volume renders with noise. The noise can be dramatically reduced by increasing the volume samples and anti-aliasing levels. Ignore Self Shadowing When on, the object does not cast shadow onto itself. Override Geometry Anti-aliasing When on, the surface overrides the geometry anti-aliasing settings. TIP Motion-blurred objects ignore any changes to the Override Geometry Anti-aliasing settings. The blur generally hides any aliasing artifacts.

Level Select one of the following options: Level 1 The default. It takes 32 visibility samples. Level 2 Takes 96 visibility samples. Level 3 Takes 288 visibility samples. Level 4 Takes 512 visibility samples. Level 5 Takes 800 visibility samples. Level 5 gives the best edge anti aliasing quality, but it is also the most expensive (in both memory and speed). Override Shading Samples When on, the surface overrides the global shading sample settings in the Render Settings window on page 376.

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Shading Samples Sets the minimum number of times Maya samples each pixel. For example, if set to 1, Maya samples each pixel once; if set to 8, Maya samples each pixel 8 times. The number of shading samples taken per pixel is limited by the number of visibility samples performed by the Edge Anti-Aliasing computation. So, if you use Medium Quality (which performs 8 visibility samples per pixel), you cannot get more than 8 shading samples regardless of the Shading Samples attribute setting. Since Shading Samples computation is very expensive, you should try adjusting the Max Shading Samples first. See Max Shading Samples on page 513. Max Shading Samples Sets the maximum number of times a pixel is sampled during the second pass of a Highest Quality render (adaptive shading pass). The higher the number, the longer the rendering takes, but the more accurate the resulting image is. Max Shading Samples has an effect only when used in conjunction with Highest Quality edge anti-aliasing. Also, depending on the requirements to compute an accurate solution, the number of Shading Samples taken can be less than the number of Max Shading Samples. TIP ■

Occasionally, when an object is moving, the object’s textured edges look distorted. To resolve this, try increasing the number of Max Shading Samples.

■

Sometimes, skinny highlights can exhibit roping or flickering artifacts. Try increasing the Max Shading Samples setting. You may also need to increase the Shading Samples setting, but you can set it on a per-object basis.

Override Visibility Samples Activate the layer override on the global maximum number of motion blur visibility samples to be taken for surfaces during rendering. Level Sets the number of visibility samples for the layer override. Override Volume Samples When on, the object overrides the global volume shading settings and you can turn on the Depth Jitter option in Render Settings window. Level

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Sets the number of volume samples for the layer override.

Render Pass Options (legacy for mental ray) For a description of each render pass, see Render passes on page 301.

mental ray (legacy for mental ray) Select this option to render a global illumination pass for this layer. For more information on global illumination, see Global illumination.

Render pass nodes Render pass Attribute Editor

Use this node to set your options for your render pass. Render Pass Options Renderable Select this option to set the render pass as renderable. When set as renderable, the render pass (frame buffer) is defined in mental ray and written to disk upon rendering completion. Type Select the desired render pass type from the drop-down list. Numbers of Channels Set the number of channels for your render pass output. Some render passes support all types of channels, while some others only support a limited number of channels. Frame Buffer Type Select the framebuffer type from the drop-down list. Filtering Enable this option to use the same filter settings as selected in the Render Settings window. This option should be enabled in most cases. Pass Group Name Use this attribute to sort your render passes into logical file groups. The pass group name that you enter in this field is appended to the image file name when you include the render token in your File name prefix attribute in the File Output section in the Render Settings: Common tab on page 377.

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For example, group your diffuse, specular and shadow passes into a pass group called Illumination. When rendering with openEXR, add the render token to your File name prefix attribute. All passes with Pass Group Name set to Illumination are concatenated under the Illumination exr file. A render pass node may also have several of the following attributes, depending on the pass type: NOTE The terms hidden and visible refer to whether or not an object is associated with the pass through one or more pass contribution maps. Use Transparency When this option is disabled, all objects in the scene turn opaque. Holdout Allows hidden objects to occlude. This option is useful for some compositing workflows. Hidden Geometries Visible in Reflections Enable this option to make hidden objects appear through visible reflective objects. Hidden Geometries Visible in Refractions Enable this option to make hidden objects appear through visible refractive objects. Hidden Geometries Produce Reflections Renders the reflections of visible objects through hidden objects. Hidden Geometries Produce Refractions Renders the refractions of visible objects through hidden objects. Attenuate According to Transparency Framebuffer values are modulated by material transparency. Only available for render pass types where it is pertinent. For example, if you render a 50% transparent surface and the object behind it is opaque, the diffuse for the opaque object is dimmed by 50% and written as is, since the object is being seen through a transparent surface. Min Reflection Level / Max Reflection Level The minimum and maximum number of times a light ray can be reflected. The maximum value is clamped by the Max Trace Depth value set in the Render Settings window, Quality tab. Min Refraction Level / Max Refraction Level The minimum and maximum number of times a light ray can be refracted. The maximum value is clamped by the Max Trace Depth value set in the Render Settings window, Quality tab.

Normalized 2D Motion Vector render pass attributes The Normalized 2D Motion Vector pass node also includes these attributes:

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Automatic Max Pixel Disp. / Max Pixel Disp. If the Automatic Max Pixel Disp. option is selected, Maya calculates the maximum image resolution. For example, if the image resolution is 640x480, the biggest axis of the image, 640, is used. Otherwise, if the Automatic Max Pixel Disp. option is disabled, Maya uses the value specified in Max Pixel Disp. Min. Disp. Range / Max. Disp. Range Specify how the motion vector should be remapped. For example, the default is 0 for the minimum and 1 for the maximum, with a maximum displacement of 256. Therefore, any value less than 0 is remapped to 0. Any value greater than 256 is remapped to 1, and a displacement of 128 is remapped to 0.5. Extract Magnitude If enabled, the length of the 2D vector is placed in the z-component. The length is also normalized; so, if the length is 256, the value written in blue channel would be 1 (assuming that the displacement value is 256).

Camera Depth render pass attributes The Camera Depth pass node also includes these attributes: Near clipping plane / Far clipping plane, and Minimum buffer value and Maximum buffer value. Use the attributes to normalize the camera depth value. For example, using the default values, any value less than 0 is normalized to 0 and any value greater than 1000 is normalized to 1. Alternatively, you can also use these attributes to clip objects out of the scene. You must enable the Remap Depth Values option in order for the near and far clipping planes and minimum and maximum buffer values to take effect.

Render pass set Attribute Editor

A render pass set is a group of render passes. Render Pass Set Options Renderable Select this option to make the render pass set renderable. By making a render pass set renderable, you are also making its member passes renderable.

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Open Relationship Editor Click this button to open the Relationship Editor to manage the list of render passes in this render pass set.

Render pass contribution map Attribute Editor

A pass contribution map associates a subset of the lights and renderable objects in the scene to one or more render passes. When rendering a given render layer, only the pass contribution maps linked to the layer are applied. Render passes that are not connected to any objects through pass contribution maps are implicitly associated to all objects. Pass Contribution Map Options Active Enable this attribute to use the pass contribution map. Open Render Settings Click this button to open the Render Settings window.

mental ray for Maya Dynamic Attributes for Rendering Dynamic Attributes for Rendering The following dynamic attributes are designed to work on Maya shape nodes. Some of these attributes are not always visible by default in the Maya user interface. However, once you have created the attribute, you can view and edit the value in the Extra Attributes section in the Attribute Editor.

mental ray Derivatives Use this attribute if you want to use mental ray derivatives for NURBS and subdivision surfaces (to interact with shaders), instead of the default mental ray for Maya derivatives. Create this attribute on the shape node as follows: addAttr -ln "miDerivatives" -at "enum" -en "none:first:second:both" -dv 0 pSphereShape1;

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Values within the range of 0 to 3 are supported for -miDerivatives. ■

0 = no derivatives

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1 = first order derivatives

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2 = second order derivatives

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3 = first and second order derivatives

mental ray Ray Offset Use this attribute to specify how much to offset a ray from the geometry. Ray Offset is useful in scenes with raytraced self-shadowing artifacts. Create this attribute on the shape node as follows: addAttr -ln miRayOffset -at "float" -dv 0.0 pSphereShape1;

This attribute is often used to help resolve shading artifacts such as the tessellation that appears in shadows or raytracing effects.

Transform node mental ray attributes Transform node mental ray rendering attributes

Find this section in some selected objects' transform node Attribute Editor.

Flags Use these flags to override your global settings. Derive From Maya Select this option to follow the global settings in the Render Settings window. Hide Select this option to hide the object in your render. Visible Use this flag to control the visibility of the selected object. Trace Use this flag to turn raytracing on or off for the selected object. Shadow Use this flag to enable or disable shadows for the selected object. Caustic Use this flag to enable or disable caustics for the selected object.

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GlobIllum Use this flag to enable or disable global illumination for the selected object.

Render Proxy Renderable

If you are using render proxies to manage your scene, use this option to set your render proxy as renderable so that it is rendered instead of your base geometry. This is a per instance flag. Therefore, if you have five instances of your base geometry, and you only want to replace three of them with your render proxy, you can use this flag to set the three instances as Renderable. Render proxies allow for more efficient renders. Using this flag, you can choose not to load and render complex geometry that you do not need in your scene. For more information regarding render proxies, see Using render proxies in your scene on page 242.

Geometry Shader Enable Geometry Shader Use this option to override your geometry with a mental ray geometry shader or a user defined mental ray shader.

Object-specific mental ray attributes Attribute Editor mental ray

Find this section in the selected object’s shape node. Expand the mental ray section of the shape node’s Attribute Editor to see these options. The following options are on by default: Visible In Transparency, Transmit Transparency, Trace Reflection, Transmit Refraction, Final Gather Cast, and Final Gather Receive.

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In most cases, you want to leave these options on. For example, you want transparency and refraction rays to be transmitted through your object, or you want reflection rays to reflect through your scene several times. In some cases, however, you may want to customize your scene by switching off one or more of these options. Refer to the descriptions below for the effects that can be obtained by unchecking each of these attributes. Visible In Transparency Uncheck this option so that the object is not be visible if behind a transparent object. Transmit Transparency Uncheck this option so that transparency rays do not transmit through the object and treats the object as if it were opaque. Trace Reflection Uncheck this option so that reflection rays stop immediately after they hit the object instead of bouncing in a scene several times. Transmit Refraction Uncheck this option so that transparency rays are transmitted through the object but refractive rays are not. Use in conjunction with Refractive Index under the Raytrace options section of the object’s shader node. Final Gather Cast Uncheck this option so that object does not contribute any light to final gather. Final Gather Receive Uncheck this option so that object does not receive any final gather light. NOTE Areas surrounding the selected object may appear darkened or shadowed even if both Final Gather Cast and Final Gather Receive are unchecked for the object. This effect occurs because although the object does not contribute any light to final gather, final gather rays still hit the object and interpret the object as dark. Render Proxy

Select your render proxy .mi file to render your render proxy instead of your base geometry placeholder. For each instance of your base geometry, you can make the selection between rendering the base geometry or replacing it with the render proxy. Use the per-instance Renderable flag. See Renderable on page 506for more information.

Bounding Box Update Proxy and geometry bounding boxes

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Update the placeholder object with both the render proxy bounding box attributes and the render proxy geometry. This is the default. Proxy bounding box only

Update the placeholder object with only the render proxy bounding box attributes but not the render proxy geometry. Geometry bounding box only

Update the placeholder object with only the render proxy geometry but not the render proxy bounding box attributes. None

Does not update the placeholder object. Anti-aliasing Sampling Override Use the Min Sample Level and Max Sample Level attributes to set the range of samples used for the selected object. Note that the min and max sample level values set for each object are bound by the global min and max sample level values. See Anti-Aliasing Quality on page 416 for more information regarding the global sample level values. Min Sample Level This is the object specific minimum number of samples per pixel used when processing an image. This value is clamped to the global min sample level value. For example, if the object specific min sample level is set to -1 and the global min sample level is set to 1, then the global setting of 1 will be used. Based on the Anti-aliasing Contrast on page 418 (adaptive) settings, mental ray for Maya will increase these samples as needed. Max Sample Level This is the object specific maximum number of samples per pixel used when processing an image. This value is clamped to the global max sample level value. For example, if the object specific max sample level

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is set to 3 and the global max sample level is set to 2, then the global setting of 2 will be used. Rasterizer Shading Quality Override / Shading Quality This attribute controls the rasterizer’s shading samples on a per-object basis. See Rasterizer Quality on page 418 for more information. Final Gather Override When on, the object overrides the global final gather settings that you have set in the Render Settings window. Final Gather Rays Controls how many rays are shot in each final gathering step to compute the indirect illumination. The default is 1000 per sample point, but this tends to be high for test renders (renders can take hours). Test rendering at lower values, usually 100 or 200, is sufficient; higher values are required for final renders. Increasing the value reduces noise but also increases the rendering time. Min Radius, Max Radius Max Radius and Min Radius control the size of the sampling region within which Final Gather rays search for irradiance information from other surfaces. With the default values, Maya calculates values that seem appropriate based on scene dimensions to speed up the render, but this calculation doesn’t allow for complex geometry. Generally, enter a value that is 10% of scene’s overall dimension for the Max Radius, then enter 0.0 for Min Radius. Make further adjustments based on scene geometry detail, how the geometry is arranged in the scene, and how the render looks. For example, use smaller radii to achieve better detailing in nooks and crannies in your scene. View (Radii in Pixel Size) This option causes the Min Radius and Max Radius of final gather rays to be calculated in pixel size, rather than in object space. This allows you to set the visual quality in pixel size, without knowing the object or scene bounds. Filter Use this to control how Final Gather uses a speckle elimination filter to prevent samples with extreme brightness from skewing the overall energy stored in a Final Gather sampling region. Neighboring samples are filtered so that extreme values are discarded in the filter size. By default, the filter size is 1. Setting this to 0 disables speckle elimination, which can add speckles but will better converge towards the correct total image brightness for extremely low accuracy settings. Size values greater than 1 eliminate more speckles and soften sample contrasts. Sizes greater than 4 or so are not normally useful. Global Illumination Override When on, the object overrides the global global illumination settings that you have set in the Render Settings window.

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Global Illum Accuracy Change the number of photons used to compute the local intensity of global illumination. The default number is 64; larger numbers make the global illumination smoother but increase render time. Global Illum Radius Controls the maximum distance at which mental ray for Maya considers photons for global illumination. When left at 0 (the default), mental ray for Maya calculates an appropriate amount of radius, based on the bounding box size of the scene. If the result is too noisy, increasing this value (to 1 to start, then by small increments up to 2) decreases noise but gives a more blurry result. To reduce the blur, you must increase the number of global illumination photons (Global illumination Accuracy) emitted by the light source. Caustics Override When on, the object overrides the global caustics settings that you have set in the Render Settings window. Caustic Accuracy Controls the number of photons used to estimate the caustic brightness. The default is 64. Higher settings (up to 100 to start, tested in small increments) larger numbers make the caustic smoother. Caustic Radius Controls the maximum distance at which mental ray for Maya considers photons for caustics. When left at 0 (the default), mental ray for Maya calculates an appropriate amount of radius, based on the bounding box size of the scene. If the result is too noisy, increasing this value (to 1 to start, then by small increments up to 2) decreases noise but gives a more blurry result. To reduce the blur, you must increase the number of caustic photons (Caustic Accuracy) emitted by the light source. Override Maximum Displace When on, the object overrides the global Max Displace settings that you have set in the Render Settings window. Maximum Displace Specifies the maximum displacement applied to object control points in a normal direction. This provides control over the otherwise automated displacement range to better focus tessellation where most needed. Set this value if you have any displaced objects in your scene. See Max Displace on page 446for more information.

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Object-specific render attributes - Attribute Editor Render Stats Find this section in some selected objects’ Attribute Editor, from the Attribute Spread Sheet (Window > General Editors > Attribute Spread Sheet) or the Rendering Flags window (Window > Rendering Editors > Rendering Flags). The Render Stats section lets you turn on or off various rendering options for selected objects. NOTE Render Stats for IBL (image-based lighting) nodes are described in Image based lighting node attributes in the Lighting guide. Casts Shadows Turns on the shadow casting ability of the surface. To make shadows render faster, for surfaces that do not need to cast shadows, turn off Casts Shadows. Consider the following: ■

If you want the object’s shadow to render—the shadow the object casts onto other objects—make sure Casts Shadows is on.

■

If you do not want the object’s shadow to render—the shadow the object casts onto other objects—turn Casts Shadows off. NOTE ■

If you render shadows separately, use the mask channel of the rendered shadow image in your compositing software to reduce the brightness of another image.

■

When you render from the Render View window, you can render only the selected objects by selecting Render>Render Selected Objects Only.

Receive Shadows Turns on the shadow-catching ability of the surface. Motion Blur Turns on motion blur for the surface. You must also turn on Motion Blur in the Render Settings window on page 376. Primary Visibility

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When on, the surface is visible in the view and renders. TIP A surface’s shadow renders, however, if its Primary Visibility is off and Cast Shadows is on. This also applies to reflections and refractions. Smooth Shading If this is on, each vertex uses its own normal vector - meaning smoother transition between two faces. If this is off, one normal vector is used for a face; 3 vertices in a triangle uses a same normal vector, resulting flat looking shading. Visible In Reflections When on, the surface reflects in reflective surfaces. This is supported by mental ray for Maya. Visible In Refractions When on, the surface refracts in transparent surfaces. This is supported by mental ray for Maya. Double Sided Determines if the surface is double-sided. If single-sided, you can decrease memory use and use the Opposite option. Opposite Opposite flips the surface normals. Double-Sided must be off to set Opposite. Geometry Anti-aliasing Override When on, the surface overrides the geometry anti-aliasing settings. TIP Motion-blurred objects ignore any changes to the Geometry Anti-aliasing Override settings. The blur generally hides any aliasing artifacts.

Antialiasing Level Select one of the following options: Level 1 The default. It takes 32 visibility samples. Level 2 Takes 96 visibility samples. Level 3 Takes 288 visibility samples. Level 4 Takes 512 visibility samples. Level 5

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Takes 800 visibility samples. Level 5 gives the best edge anti aliasing quality, but it is also the most expensive (in both memory and speed). Shading Samples Override When on, the surface overrides the global shading sample settings in the Render Settings window on page 376. Shading Samples Sets the minimum number of times Maya samples each pixel. For example, if set to 1, Maya samples each pixel once; if set to 8, Maya samples each pixel 8 times. The number of shading samples taken per pixel is limited by the number of visibility samples performed by the Edge Anti-Aliasing computation. So, if you use Medium Quality (which performs 8 visibility samples per pixel), you cannot get more than 8 shading samples regardless of the Shading Samples attribute setting. Since Shading Samples computation is very expensive, you should try adjusting the Max Shading Samples first. See Max Shading Samples on page 513. Max Shading Samples Sets the maximum number of times a pixel is sampled during the second pass of a Highest Quality render (adaptive shading pass). The higher the number, the longer the rendering takes, but the more accurate the resulting image is. Max Shading Samples has an effect only when used in conjunction with Highest Quality edge anti-aliasing. Also, depending on the requirements to compute an accurate solution, the number of Shading Samples taken can be less than the number of Max Shading Samples. TIP ■

Occasionally, when an object is moving, the object’s textured edges look distorted. To resolve this, try increasing the number of Max Shading Samples.

■

Sometimes, skinny highlights can exhibit roping or flickering artifacts. Try increasing the Max Shading Samples setting. You may also need to increase the Shading Samples setting, but you can set it on a per-object basis.

NOTE The following attributes are only applicable to volume primitives and fluid shapes. They only appear in the Attribute Editor of the shape node of a volume primitive or fluid shape.

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Volume Samples Override When on, the object overrides the global volume shading settings and you can turn on the Depth Jitter option in Render Settings window. Volume samples Adjusts the number of samples placed inside the fog volume. Depth Jitter If you set Volume Sample Override on, you can turn on Depth Jitter option. Randomizes the samples of the volume with depth which replaces banding artifacts in volume renders with noise. The noise can be dramatically reduced by increasing the volume samples and anti-aliasing levels.

3D Motion Blur Max Visibility Samples Override / Max Visib Samples Override, for the selected shape node, the global maximum number of motion blur visibility samples to be taken for surfaces during rendering.

Smooth Mesh Render

Find these attributes under the Smooth Mesh section and Subdivision Levels sub-section on the polyShape node for the selected mesh. Use Preview Level for Rendering / Render Division Levels You can set up a smooth preview in the 3D viewport and then render it. The division level controls the number of times the original version of the mesh is subdivided. The slider range is between 0 and 4. A value of 0 indicates no smoothing, in other words, rendering the hull, while a value of 4 is the highest smoothing within the range of the slider. You can input values higher than 4, up to a maximum of 7, in the text field. You should exercise caution when tweaking this attribute, however, because each time you increase the level, you multiply the number of quads by 4. By default, the same division level is used for both preview and render. To use a different Render Division Level from the Preview Division Level, unselect the Use Preview Level for Rendering option and use the Render Division Levels slider or text field to enter the desired division level for your render.

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NOTE ■

This feature can only be used with the mental ray for Maya renderer.

■

In order to obtain smooth render effects, you must enable the Export Triangulated Polygons option in the Render Settings: mental ray tabs, Options tab on page 444 under the Translation section and Performance sub-section.

Vector Renderer Control Find this section in the Attribute Editor for material nodes (Anisotropic, Blinn, Lambert, Phong, and Phong E). For information on how to set these attributes, see Set per-material vector rendering options on page 99. Hidden Edges On Transparent When you turn this attribute on, you can render edges that would usually be obscured by the object. The edges are rendered as if they are masked by the transparency. Outlines At Intersections When you turn this attribute on, an outline appears along the point where two objects intersect. Use the Edge Priority setting to resolve edge outline conflicts (when depth does not automatically do so). This attribute is also located in the Render Settings, Maya Vector tab, in the Edge Options section. Edge Priority The Edge Priority value determines which outline style is rendered at the intersection when the intersecting objects have different outline style settings, or when edges come very close to intersecting. Typically, if objects are at differing depths, the edge priority makes no difference because the object that is closer to the camera supersedes, and its outline style is rendered. This setting is useful when the depth of the objects are the same, or very close. In this situation, the edge priority can determine which object’s outline style is rendered. The higher the value, the higher its priority.

Texture Map Find this section in the Attribute Editor for NURBS, under the shape node.

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Texture Map Provides you with various adjustable attributes as well as a way to fix texture warp on objects with 2D textures. This is especially useful, for example, waving fabric, like a flag. Fix Texture Warp The Texture Map attributes only apply to NURBS surfaces. NOTE Convert to File Texture does not support Fix Texture Warp If the surface uses Fix Texture Warp, it is ignored when converting the material. If you are rendering in mental ray for Maya, Fix Texture Warp may use significant memory and result in large .mi output file size. In addition, you may notice that rendered results in mental ray for Maya are different than those in Maya Software. Fix Texture Warp adjusts a texture’s UV parameters so the texture does not rely on a NURBS object’s UV parameterization, which alleviates texture warp on objects with 2D textures. For example, if you want to create and animate a flag with a Checker texture, you can create a NURBS plane on which to map the Checker texture, transform the CVs, and turn Fix Texture Warp on in the object’s Attribute Editor. When you animate the flag by moving some of the CVs to simulate the wind blowing the flag, the checker pattern on the flag expands and shrinks appropriately.

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TIP ■

To see the textured surfaces update, you must view them in Render View (Render > Render Current Frame). Re-render the scene to see the fixed texture.

■

Because computing exact arc-lengths is very expensive, Fix Texture Warp is a compromise used to achieve well spaced UV texture values with chord length (which measures the length of a line drawn between two points on the surface). Use this feature to apply textures more evenly on surfaces with uneven parameterization.

■

Fix Texture Warp is applied on a per-NURBS surface basis.

Setting the grid size When Fix Texture Warp is on, Maya texture maps a 2D NURBS surface based on the chord length of a grid placed on the surface. You can determine the size of the grid by the value you specify in the Grid Division Per Span U and Grid Division Per Span V, and the corresponding number of spans on the surface. The default grid size is 4, and the result is a multiple of 4. Grid Div Per Span U Specifies the number of divisions per span of the Chord Length grid along the U parameter. Grid Div Per Span V Specifies the number of divisions per span of the Chord Length grid along the V parameter.

Tessellation NURBS objects tessellation Display render tessellation Shows or hides (default) the tessellation triangles so that you can have more control while adjusting settings. NOTE This option does not display displacement mapping. In the main Maya window, select Modify > Convert > Displacement to Polygons to preview the effect of your tessellation and displacement together, then discard the generated polygon object when you are finished previewing.

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Refresh tessellation When advanced tessellation with min screen is on, the tessellation only updates when refresh is pressed. Triangle count This is the number of render triangles in the surface when a tessellation is displayed. Curvature tolerance See Curvature Tolerance on page 329. U Division Factor, V Division Factor See U Division Factor, V Division Factor on page 329.

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Index .mi files exporting 186, 241 .mi format exporting to 186 2D Blur memory Limit attribute 396 2D motion blur artifacts 145 rendering problems 144 3D Blur Visib attribute 389 3D Motion Blur 16 3D Motion Blur Production attribute 388

A Acceleration Method attribute 421 Accuracy (Caustics) attribute 434 Accuracy (Final Gather) attribute 438 Accuracy (Global Illumination) attribute 433 Accuracy (Photon Volume) attribute 436 Adaptive Sampling attribute 417 Adobe Illustrator image format 54 Advanced Tessellation for surfaces 331 aliasing 146, 283 All Channels Render View 477 All Double sided attribute 456 All Renderable Cameras for tessellation 329 All Single sided attribute 456 All Surfaces for tessellation 327 Alpha Channel Render View 477 Alpha Channel (Mask) 383 alpha channels enabling 89 premultiplication 78 Alpha mode attribute 430

Alpha Source attribute 487 Ambient Occlusion (Render Settings) 444 Angle of view 20 angle of view, cameras 19 animation batch rendering 52 command line rendering 53, 133, 186, 239 low-res rendering 128 rendering single frame 52 swimming 143 troubleshooting 143 Animation mental ray for Maya 176 animations test render 128 Anti-alias Anti-aliasing Quality, Render Settings 388 Hardware Render Settings 490 anti-aliasing about 154 adjusting 157 blobby surfaces 143 Anti-aliasing Sampling Override mental ray 508 Antialiasing Level Render Stats 499, 512 aperture (fstop) 15 Apply Fog in Post Render Options 397 Apply Fog in Post, IPR 151 Apply tessellation, NURBS 327 approximation about 39, 181 controlling fine 208 default settings 181 fine 183 vs. tessellation 39 approximation node creating 203

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deleting 206 approximation nodes 182 approximation settings 181 overriding 207 Approximation settings 209 approximation styles 183 Area Gradient (SWF and SVG only) 464 Area Lights mental ray 175 artifacts 2D motion blur 145 about 155 clipping plane 155 fixing 157 troubleshooting 143 aspect ratio pixel 65, 88 At Top/At Bottom attribute 392 atmosphere 396 Attribute Editor Rendering Flags 176 surface settings 363 Attributes option in Hardware Render Buffer 491 Auto Memory Limit 320, 325 Auto Render Region in Render View 476 Auto Render Threads 320, 322, 325 Auto Resize in Render View 476 Auto Tiling 320, 322, 325 Autodesk Pix format 54 Automatic tessellation mode 328 Average Color 463 AVI image format 54 azimuth description 18

B Back attribute 409 background rendering problems

520 | Index

144

Background Color Display Options 491 Background Color attribute Environment attributes 352 Basic camera 14 Batch Render 324 about 52 advantages 52 and IPR 125 cancel 326 error handling 177, 251 show 326 Batch Render Frame window 132 Best Guess Based on Screen Size primary tessellation 331 Bias Raytracing Quality 394 bitmap image file format 59 Blend Specular with Alpha option 458 blobby surface anti-aliasing problem 143 block ordered textures 163 Blue Channel Render View 477 Blur By Frame, Motion Blur 394 Length, 2D Motion Blur 395 Sharpness, 2D Motion Blur 395 Blur by Frame attribute 457 BOT 163 BOT files 163 Both attribute 409 Both Fields Interlaced 392 Separate 392 Bounding Box Dolly camera setting 356 Box attribute 434 Box Filter attribute 418 BSP Depth attribute 422 BSP settings 248 BSP Size attribute 422 BSP2 Attribute 421 Bump mapping 279 Bump Resolution attribute 456

Bump Texture Resolution 456 By Frame Hardware Render Settings 487 Image File Output 87, 381 Renumber Frames, Render Settings 381

C Cache Density (Ambient Occlusion) attribute 444 Cache Points (Ambient Occlusion) attribute 444 cache size limit, for approximation 208 Caching (Ambient Occlusion) attribute 444 Calculate 321 Calculation attribute 427 camera Center of Interest option 313, 354 Camera optimizing, render faster 162 Select Camera option 340 Camera and Aim 14 Camera Aperture 348 Camera Icons attribute 491 Camera Properties attributes 313 Camera Settings option, View menu 340 camera tools 17 Camera Tools option, View menu 28 Camera, Aim, and Up 14 cameras adjusting attributes 22 aiming 17, 27 azimuth 18 changing settings 340 creating 22 dollying 17 elevation 18 field chart 344 fill 344 film gate 341 fly 19 frustrum 341 gate 341 gate mask 343

Gate Mask color 354 Gate Mask opacity 353 horizontal 344 looking through 26, 29–30 making renderable 23 oversan 345 perspective 340 resolution gate 343 rolling 18 safe action 344 safe title 21, 344 save movements 30 selecting current 26 tilt 18 tracking 17 tumbling 17 types of 14 undoable movements 340 viewing vs. rendering 13 yaw 18 zoom 18 Cancel Batch Render 326 cancelling IPR 124 Casts Shadows Render Layer Member Overrides 498 Render Stats 511 Casts Shadows attribute Render Stats attributes 498, 511 Caustic Rendering Flag 176 Caustic Accuracy mental ray 510 Caustic Filter Kernel attribute 434 Caustic Filter Type attribute 434 Caustic Radius mental ray 510 causticPhotonsEmit 267 caustics troubleshooting 162 Caustics attribute 434 Caustics Override mental ray 510 Caustics/Global Illumination attribute 447 Center of interest 313, 354

Index | 521

channels about 67, 78 premultiplication 78 Chord Height Ratio attribute 332 Chord Height Ratio, Use 332 Cineon format 55, 167 client 200 client setup 252 Clip Final Shaded Color attribute 398 clipping plane artifacts 155 clipping planes about 21 Close IPR File Render View window 472 Close option Hardware Render Buffer 491 Closest Visible Depth Depth Type 352 Collision Icons attribute 491 color channels about 67 enabling 89 Color Contrast attribute 429 Color Resolution attribute 455 Color Texture Resolution 455 Colorclip attribute 430 Combine Fills and Edges (SWF only) 459 command line rendering 53, 133, 186, 239, 262 common tab Render Settings 377 component shading groups render layers 108 Composite Threshold 399 compositing arranging objects 79 rendering tips 78 Compositing Interoperability Plug-in 80 compositingInterop 137–138 Compress (SVG only) 460 Compression attribute Image File Output attributes 380 Compute From for tessellation 329

522 | Index

Cone Angle 161, 250 Cone attribute 434 Console 177, 251 Contours 217, 410 Contrast Sensitive Production attribute 388 control visibility/reflection per layer 120 Coverage attribute Anti-aliasing Quality attributes 391 CPUs multi-thread rendering 401 use all available for multi-thread rendering 401 Culling attribute 456 Culling Threshold attribute 457 Current Frame for tessellation 329 Current View for tessellation 329 Curvature Tolerance Set NURBS Tessellation 329 Curve Tolerance 460 Custom attribute 388, 415, 454 custom element 270 Custom Extension attribute 393 Custom Globals 176 Custom Globals attribute 453 Custom Motion Offsets 429 Custom Motion Vectors 266 Custom Sampling attribute 417 Custom Scene 176, 453 Custom Scene attribute 453 Custom Scene Text Render Text 454 Root Group Text 454 Custom Textures 176 Custom Vertex Data 176 Customization attribute 451 customizations mental ray for Maya 176 Cutout opacity 266

D Data Type 307 Data Type attribute

429

Default Field Extension (o and e) attribute 393 Density (Importons) attribute 437 Depth attribute Output Settings attributes 351 depth channel description 79 Depth Channel (Z Depth) 383 depth channels about 67, 78 enabling 89 depth file description, for cameras 351 depth files creating 89 depth information IFF files 174 Depth Jitter Render Layer Member Overrides 499 Render Stats 514 depth map shadows optimizing 161, 250 Depth of Field rendering 25 Depth Of Field 350 Depth Of Field attribute 350 Depth Type Closest Visible Depth 352 Furthest Visible Depth 352 Output Settings attributes 352 Depth-of-field 280 depth-of-field samples override 271 derive from Maya 181, 278 Desaturate attribute 431 Detail Level 460 Detail Level Preset 460 Detail Shadow map 424 Device Aspect Ratio attribute 387 Diagnose Bsp 422 Diagnose BSP attribute 445 Diagnose finalgather 440, 445 Diagnose Grid 251 Diagnose Grid attribute 445 Diagnose Photon 251 Diagnose Photon attribute 436, 445 Diagnose Photon Density 251

Diagnose Samples 251 Diagnose Samples attribute 417, 444 diagnosing scenes 156, 197 Diagnostics 251 differences mental ray for Maya 174 Diffuse Render Layer Pass 302 Direct Illumination Shadow Effects attribute 435 Disable Animation Detection 264 Disable DG Cycle Detection 265 Disk Based Dmaps 161, 250 disk swapping 271 Displace Motion Factor attribute 427 displacement 279 displacement mapping performance 160, 249 troubleshooting 147 Display Alpha Channel button Render View window 480 Display Field Chart attribute 354 Display Film Gate attribute 353 display layers merge when importing files 122 Display menu Render View window 477 Display Options attributes cameras 353 Hardware Render Settings 491 Display Real Size button Render View window 480 Display Resolution attribute 353 Display RGB Channels button Render View window 479 Display Safe Action attribute 354 Display Safe Title attribute 354 Display Shadows attribute 489 distributed rendering 169, 199 Dither attribute 431 Dithered option Render View window 478 Dmap Filter Size 161, 250 Dmap Focus attribute 161, 250 Dmap Resolution 161, 250

Index | 523

dofLensSamples 271 Dolly Bounding Box camera setting 356 camera settings 356 Local camera setting 356 Snap box dolly to camera settings 356 Surface camera setting 356 dollying, cameras 17 Double Sided Render Layer Member Overrides 499 Render Stats 512 Draft attribute 415 Draft motion blur attribute 415 DraftRapidMotion attribute 415 Draw Style attribute 489 duplicate render layers 118 Dynamic Attributes 263, 504

E Edge Anti-aliasing attribute 388 Edge Color 468 Edge Detail 469 Edge Smoothing attribute 490 Edge Style 468 Edge Swap Set NURBS Tessellation 330 Edge Weight 468 edges rendering problems 143 troubleshooting 146 elevation description, for azimuth elevation tool 18 Emitter Icons attribute 491 Enable Default Light 387 Enable Default Light attribute 387 Enable Depth Maps attribute 398 Enable Map Visualizer attribute 435, 440 Enable Stroke Rendering attribute 402 End Frame attribute Image File Output attributes 87, 381 Image Output Files attributes 486 Env. Rays (Irradiance Particles) attribute 443

524 | Index

Env. Scale (Irradiance Particles) attribute 443 Environment (Irradiance Particles) attribute 443 Environment attributes 352 Environment Fog attribute 396 error handling mental ray for Maya 177, 251 errors, rendering 166 Even Field 392–393 Exact 176, 180 examples render layers 71 export to mi 241 to mi using the command line 242 Export All Incoming Shaders 310 Export All Layers to Toxik 2007 334 Export Custom Colors attribute 452 Export Custom Data attribute 452 Export Custom Text attribute 452 Export Custom Vectors attribute 452 Export Entire Child DAG 311 Export Exact Hierarchy attribute 447 Export Full Dagpath attribute 447 Export Hair 448 Export Light Linker attribute 452 Export Maya Options attribute 452 Export Motion Segments 449 Export Nurbs Derivatives attribute 451 Export Objects On Demand 265 Export Objects On Demand attribute 451 Export Polygon Derivatives attribute 450 Export Render Proxy attribute 449 Export Selected Layers to Toxik 2007 335 Export Shadow Shader 264 Export Shape Deformation attribute 450 Export State Shader attribute 451 Export Textures First attribute 447 Export to Toxik 2007 135, 335 Export to Toxik 2008 139, 336 Export to Toxik 2009 337 Export Toxik IMSQ File 334 Export Triangulated Polygons 449

exporting .mi files 186, 241 optimizing .mi format Extension attribute 486 extension, image 86

files 186

F F Stop attribute 351 Faces attribute 409 Falloff Start attribute 441 Falloff Stop attribute 441 Far Clip Plane attribute 315 far clipping plane 21 feedback from IPR 150 Field options 392 Field Chart option 344 Field Dominance Even Fields 392 Odd Fields 392 render options 392 Field Dominance attribute 144 Field Extension render options 393 Field Icons attribute 491 Field Options attributes 391 field rendering 65 fields 66 description 66 Even 393 interlacing 92 rendering 91 rendering problems 144 vs. frames 65 File Export 174 file format, image 86 file formats bitmap vs. vector 54 rendering 53 File menu Render View window 472 File Name Prefix attribute 377 file name, image 86 Filename attribute 486

rendering output location 64 Fill Objects 461 Fill option 344 Fill Style 461 Film Aspect Ratio attribute 348 Film Back attributes 348 Film Back Properties attributes 314 Film Gate attribute 348 Film Gate option 341 Film Offset attribute 348 Filter attribute 441 mental ray 509 Filter Size attribute 419 final gather troubleshooting 162, 283 Final Gather attribute 437 Final Gather Cast mental ray 507 Final Gather Override mental ray 509 Final Gather Rays mental ray 509 Final Gather Receive mental ray 507 fine approximation 183 controlling triangles 208 setting cache limit 208 Fine Approximation 209 Fine Displacement 209 Fix Texture Warp 516 description 50 Fixed Sampling attribute 417 Flash rendering 8 Flash Version (SWF only) 459 flicker about 154 fixing 157 flickering animations troubleshooting 147 Flipbook Options 493–494 Flipbooks menu Hardware Render Buffer 493 Fly Tool 19 fly, cameras 19

Index | 525

focal length 19 Focus Distance attribute 350 Focus Region Scale attribute 351 fog motion blur artifacts 145 Fog Shadow Samples 161, 250 Force Displacement Animation 267 force lights emitted photons 267 Force Motion Vector Computation attribute 450 Force On-demand Translation 265 force triangle export of polygon meshes 267 format, image file setting 86 Four Color 462 frame rendering 52 Frame All option Maya View menu 30 Frame Image option Render View window 473 Frame Padding attribute 87, 380 Frame Range, Use for tessellation 328 Frame Rate (SWF and SVG only) 459 Frame Region option Render View window 473 Frame Selection 30 Frame/Animation Ext attribute 87, 380 framebuffers 303 create 304 delete 304 edit 304 User Buffer Attributes 307 frames 67 batch rendering 52 command line rendering 53, 133, 186, 239 rendering 91 rendering single 131 vs. fields 65 Frames render 392 Freeze 439 Front attribute 409

526 | Index

frustrum 341 renderable 343 fstop 15 Full Color 463 Full Image Resolution attribute Furthest Visible Depth Depth Type 352

489

G Gamma attribute 429 Gamma Correction attribute 398 gate 341 Gate Mask color 354 Gate Mask opacity 353 Gate Mask option 343 Gauss attribute 434 Gaussian Filter attribute 418 geometry mental ray approximation 184 NURBS 41 Geometry Antialiasing Override Render Stats 512 Geometry Mask attribute 489 geometry shaking mental ray 276 geometry types mental ray for Maya 184 gGlobal illumination troubleshooting 162 GIF format 55 Global Illum Accuracy mental ray 510 Global Illum Radius mental ray 510 Global Illumination attribute 433 Global Illumination Override mental ray 509 globIllPhotonsEmit 267 Globillum Rendering Flag 176 Grab Swatch to Hypershade and Visor button Render View window 473 Green attribute 391

Green Channel option Render View 477 Grid attribute 491 Grid Div Per Span U Fix Texture Warp 517 Grid Div Per Span V Fix Texture Warp 517 Grid Size 251 Grid Size attribute 445 guidelines, in scene views 24

H Hardware Environment Lookup option 457 Hardware Geometry Cache attribute 457 hardware rendering 3 Render Settings 454 HDR images 175 HDRI 175 HDTV 167 Height attribute Image Size attributes 386 Resolution attributes 88 Hidden Edges 469 High Quality attribute 389 High Quality Renderer 360 Highest Quality attribute 389 Highlight Level (SWF and bitmap formats only) 467 highlights troubleshooting 148 Highlights (SWF and bitmap formats only) 466 Horizontal Film Aperture attribute (see Camera Aperture attribute) 314 Horizontal Film Offset attribute (see Film Offset attribute) 314 Horizontal option 344

I IBL attribute 432 IFF image depth information 174 Ignore Film Gate attribute 397

Ignore Glows Render View 477 Ignore Self Shadowing Render Layer Member Overrides 499 Ignore Shadows Render View 477 Image attribute Output Settings 351 Image Based Lighting attributes 432 image file formats setting 86 Image File Output attributes 377 Image Format attribute Image File Output attributes 86, 379 Image Output Files attributes 487 Image Output Files attributes 486 Image Plane attribute Environment attributes 353 image plane, display options IPR 150 Image Size attributes 384 images directory 88 extension 86 fields 66 file format 86 file name 86 frames 67 name 86 pixel aspect ratio 88 premultiplied 78 rendering quality 153 rendering speed 153 resolution 88 images, keeping rendered Render View 480 images, removing all Render View 481 images, removing current Render View 481 Importons 437 Include Edges 467 Indirect Passes (Irradiance Particles) attribute 443 Interactive Photorealistic Rendering (see IPR) 47

Index | 527

interactive rendering, multi-threaded 401 interlacing description 66 Intermediate 454 Intermediate Quality attribute 388 Interpoints (Irradiance Particles) attribute 443 Interpolate (Irradiance Particles) attribute 443 Interpolate Samples 307, 430 IPR about 47 batch rendering 125 canceling 123 cancelling 124 how it works 48 limitations 49 options 98 pausing 123 rendering with 123 saving 123 troubleshooting 149 IPR default light 49 IPR menu Render View window 475 IPR Quality Render View Window 475 IPR Render Current Frame 321 IPR Render option Render View window 475 IPR Tuning Options Render View window 475 IRP troubleshooting 145 Irradiance Particles 442

J Jitter attribute 419 Jitter Final Color attribute Journal 30 JPEG format 56

528 | Index

398

K Keep Image Render View 480 Keep Image in Render View option Render View window 473 Keep Motion Vectors 2D Motion Blur 396

L Label 266 Lanczos attribute 419 Large BSP attribute 421 Layered Shader performance 160, 249 layers, display merge when importing files 122 layers, render assign component shading groups 108 blend modes 112 control visibility/reflection per layer 120 copy 118 merge when importing files 122 name 119 overrides 102, 105 presets 294 recycle render output for layers 119 working with 100 Leaf Primitives attribute 401 lens 19 Lens Properties attributes 313 Light Icons attribute 491 Lighting Mode attribute 488 lightMapsNetwork 274 Line Smoothing attribute 489 Linear 176, 180 Linux setup 252 Local Dolly camera setting 356 Locked Tumble camera setting 355 Logfile 177, 251 Look At Selection 29

Look Through Selected option, Panels menu 26 Low Quality attribute 389 Luminance option Render View window 477

M Maintain Width/Height Ratio attribute 386 Manual tessellation mode 328 Map File (Irradiance Particles) attribute 444 mask description, for cameras 351 Mask attribute Output Settings attributes 351 Mask Channel or alpha channel 79 mask channels about 78 about, alpha channels about 67 enabling 89 modifying 90, 237 matte opacity 279 Matte Opacity attribute 90–91, 237–238 Matte Opacity Mode attribute 90–91, 237–238 matte transparency (see Matte Opacity) 237 matte transparency, (see Matte Opacity) 90 Max 3D Blur Visib attribute 390 Max Depth (Importons) attribute 437 Max Displace 446 Max Photon Depth attribute 435 Max Radius mental ray 509 Max Radius attribute 442 Max Sample Level mental ray 508 Max Sample Level attribute 417 Max Shading attribute 389

Max Shading Samples Render Layer Member Overrides 500 Render Stats 513 Max Shading Samples attribute 389 Max Trace Depth attribute 420, 441 Max Visib Samples attribute 390 Maya derivatives attribute 450 Maya Hardware Render Settings 454 Maya IFF format 56 Maya Vector Render Settings 459 maya.rayhosts 201 maya.rayrc 202 Maya16 IFF format 56 Medium Quality attribute 389 MEL commands run at render time 68 Memory and Performance Options 401 Memory and Performance Options attributes 399 memory exceptions 143 Memory Limit 321, 326 memory mode 272 memoryMode 272 mental ray approximation 39 Area Lights 175 BSP settings 248 configuration files 201 exporting .mi files 241 exporting files 186 extra Render Settings 289 geometry shaking 276 motion blur 180 network rendering 199 output window messages 203 Render Settings 404 rendering problems 277–278 rendering with 241–242 mental ray Derivatives 504 mental ray for Maya Animation 176 customizations 176 differences 174 error handling 177, 251

Index | 529

geometry types 184 NURBS surfaces 184 polygonal meshes 185 shading networks 174 subdivision surfaces 185 mental ray Ray Offset 505 mental ray specific image formats 177 mentalrayOutputPass node 308 mentalrayUserBuffer node 307 mentay ray approximation 181 merge display layers when importing files 122 Merge Distance (Caustics) attribute 434 Merge Distance (Global Illumination) attribute 433 Merge Distance (Importons) attribute 437 Merge Distance (Photon Volume) attribute 437 merge render layers when importing files 122 Mesh Gradient (SWF and SVG only) 464 miAnimated 264 miCustomMotion 266 micutAwayOpacity 266 miData 263 miDefaultOptions node 306 miDeformation 187 miDerivatives 504 miDiskSwapDir 271 miDiskSwapLimit 271 miDisplaceAnimation 267 miElement 270 miExportCCMesh 268 miExportElement 270 miExportMaterial 270 miExportShadowShader 264 miLabel 266 miMaterial 270 Min Edge Angle 469 Min Radius mental ray 509 Min Radius attribute 442 Min Sample Level mental ray 508

530 | Index

Min Sample Level attribute 417 Min Screen attribute Secondary Tessellation Attributes 333 miPhotonsOnly 268 miPlaceholder 265 miRayOffset 505 miReflection 268 miRefraction 268 miShadingSamples 270 miTangents 187 Mitchell attribute 419 miTransparency 268 miTrianles 267 Mode U attribute Tessellation 331 Mode V attribute Tessellation 331 moire patterns 419 Motion Back Offset 429 motion blur about 16 artifacts 145 troubleshooting 148 Motion Blur 176, 180 2D troubleshooting 144 creating 96, 239 diagnostics 166 Render Layer Member Overrides 498 Render Stats 511 Tips 396 Motion Blur attribute 394, 408, 426, 457 Multi-Pass Render Options 490 Motion Blur attributes Create Camera Options 316 Render Settings window 394 Motion Blur By attribute 426 Motion Blur Shadow Maps attribute 425, 427 Motion Blur Type attribute 394 motion picture rendering fields 65 Motion Quality Factor attribute 428 Motion Steps attribute 428 Movement Options attributes cameras 354

Multi Pass Rendering attribute 490 Multi Processing 401 Multi-Pass Render Options attributes 490 multi-pixel filter 94 multi-processor rendering 132 multi-render pass pass contribution maps 369 render pass contribution map node 504 multi-render passes 188, 218, 224, 233 Create Render Passes window 470 file output 60 Render Layer Editor 367 render pass contribution map node 504 render pass node 501 render pass set node 503 Render Settings Passes tab 404 multi-thread interactive rendering 401 multiple processors 98

N name images, setting 86 naming render layers 119 Near Clip Plane attribute 315 near clipping plane 21 Network 321–322, 326 network baking turn off 274 network rendering 169, 199, 262 troubleshooting 284 No Field Extension attribute 393 No Gate option 341 nodeCycleCheck 265 nodes approximation 182 creating approximation 203 mentalrayOutputPass, output pass mental ray node 308 NTSC 144 NTSC video 66, 167 Number of CPUs to use 401 Number of Exposures attribute 458

Number of Processors to Use attribute 132, 324 Number of Samples 455 Number of Samples attribute 417, 455 Number U attribute Tessellation 332 Number V attribute Tessellation 332 NURBs multi-uv rendering problems 141 NURBS approximation 184 display tessellation 43 surfaces 41 NURBS surfaces mental ray for Maya 184

O objects framing with camera 29–30 mental ray approximation 184 rendering 85 tesselation settings 41 vibrating 144 when to tessellate 43 Odd Field attribute 393 Odd Fields 392 Only Render Strokes attribute 403 Open Image option Render View window 472 Open in Browser (SWF only) 459 Open IPR File Render View window 472 Open Render Settings Window 479 Opposite Render Layer Member Overrides 499 Render Stats 512 Optimize Animation Detection 449 Optimize Animation Detection attribute 448 Optimize for Animations attribute 441 Optimize Instances 159, 248 Optimize Instances attribute 400 Optimize Non-animated Display Visibility 448

Index | 531

Optimize Raytrace Shadows 449 Optimize Vertex Sharing 449 optimized texture format 197 optimizing cameras 162 scenes 158, 247 shadows 161, 250 Options attribute 494 Options menu Render View window 476 Ortho step Tumble camera setting 355 orthographic camera width of 317 Orthographic Camera 317 Orthographic views camera settings 355 Orthographic Width 317 Outlines at Intersections 469 Output Settings 334 Output Settings attributes 351 Output Window 177, 251 Override Geometry Anti-aliasing Render Layer Member Overrides Override Shading Samples Render Layer Member Overrides Override Visibility Samples Render Layer Member Overrides Override Volume Samples Render Layer Member Overrides overriding attributes per layer 109 Overscan camera attribute 343 Overscan option 345

P PAL 144 PAL video 66, 167 parallel rendering 199 particle rendering mental ray 280 Particles attribute 390 Pass Custom Depth Channel 452 Pass Custom Label Channel 453 passes about 301

532 | Index

499 499 500 500

Pause IPR Tuning Render View window 476 Per object attribute 455–456 Per polygon attribute 455 Per Span # of Isoparms primary tessellation 331 Per Surf # of Isoparms primary tessellation 331 Per Surf # of Isoparms in 3D primary tessellation 331 Performance attribute 448 Perspective option 26, 340 Photon Auto Volume attribute 436 Photon Density attribute 436, 445 Photon Map File attribute 435 photon only lights 268 Photon Reflections attribute 435 Photon Refractions attribute 435 Photoshop format 57 Pix format 54 pixel aspect ratio 88 about 65 Pixel Aspect Ratio attribute 88, 387 Pixel Filter Type attribute 390 Pixel Filter Width X attribute 391 Pixel Filter Width Y attribute 391 pixels 48, 65, 67 plug-ins multi-pixel 94 PNG format 57 polygonal meshes mental ray for Maya 185 polygonal surfaces 50 polygons approximation 184 port number troubleshooting 284 Post Fog Blur Render Options 397 Post Fog Blurt Render Options 397 Post Render MEL attribute 92 Pre Render MEL attribute 92 Precompute Photon Lookup attribute 440 preemultiplied images, defined 78

Presets Render Resolution 384 Presets attribute 415 presets, mental ray Custom 415 Draft 415 DraftMotionBlur 415 DraftRapidMotion 415 Preview 416 PreviewCaustics 416 PreviewGlobalIllum 416 PreviewMotionBlur 416 PreviewRapidMotion 416 Production 416 ProductionMotionBlur 416 ProductionRapidFur 416 ProductionRapidHair 416 ProductionTraceDetail 416 Preview 454 Preview Animation attribute 445 Preview attribute 416 Preview Convert Tiles 446 Preview Final Gather Tiles attribute 440 Preview Motion Blur attribute 445 Preview Quality attribute 388 Preview Render Tiles attribute 446 Preview Tonemap Tiles 446 preview workflow render layers 70 preview, renders 1 PreviewCaustics attribute 416 PreviewFinalGather attributepresets, mental ray PreviewFinalGather 416 PreviewGlobalIllum attribute 416 previewing Resolution Gate 24 previewing render layers 111 PreviewMotionBlur attribute 416 PreviewRapidMotion attribute 416 Primary Final Gather File attribute 439 primary tessellation 40 Primary Tessellation Best Guess Based on Screen Size 331 Per Span # of Isoparms 331 Per Surf # of Isoparms 331

Per Surf # of Isoparms in 3D 331 Primary Visibility Render Layer Member Overrides 498 Render Stats 512 problems messages 166 rendering 166 processor, multiple 98 Production 455 Production attribute 416 Production Quality attribute 388 Production Quality with Transparency 455 ProductionMotionBlur attribute 416 ProductionRapidFur attribute 416 ProductionRapidHair attribute 416 ProductionRapidMotion attribute 416 ProductionTraceDetail attribute 416 projection textures troubleshooting 143 Prune Invisible Parts 448 Prune Objects Without Material 448

Q quality raytracing 96 Quantel format 57 QuickDraw format 57 Quicktime image format (UNIX only) 57

R Radius (Caustics) attribute 434 Radius (Global Illumination) attribute 433 Radius (Photon Volume) attribute 436 Ramp Shader Motion Blur tips 396 Rasterizer attribute 407 Rasterizer Pixel Samples 425 rasterizer shading samples override 270 Rasterizer Transparency 422 Rasterizer use opacity 431 Raw attribute 430 Ray Depth Limit 162, 251

Index | 533

Ray Tracing attribute 419 Rays (Ambient Occlusion) attribute 444 Rays (Irradiance Particles) attribute 442 rayserver troubleshooting 284 raytraced shadows optimizing 162, 251 raytracing setting quality 96 Raytracing description 96 Raytracing attribute 393, 407 Raytracing Quality attributes 393 Real Size option Render View window 473 Rebuild (Irradiance Particles) attribute 443 Rebuild attribute 439 Rebuild Mode attribute 425 Rebuild Photon Map attribute 435 Receive Shadows Render Layer Member Overrides 498 Render Stats 511 Recursion Depth attribute 401 recycle rendered images 119 Red attribute 391 Red Channel option Render View 477 Redo Previous IPR Render option Maya Render menu 323 Render View window 475 Redo Previous Render 131 Redo Previous Render option Maya Render menu 321 Render View window 474 Reflection Depth 467 Reflection Limit 160, 249 Reflections attribute 393, 420 Reflections attribute (final gather) 441 Refraction Limit 160, 249 Refractions attribute Raytracing Quality attributes 393, 420 Refractions attribute (final gather) 441 Refresh IPR Image Render View window 475

534 | Index

Regular BSP attribute 421 Remote Machine Name attribute 325 Remove All Images from Render View option Render View window 473 Remove Image Render View 481 Remove Image from Render View option Render View window 473 remove material overrides render layers 105 Render 2D Motion Blur attribute 402 Render All Layers option Render View window 474 Render Current Frame 320 Maya Render menu 131 Render Diagnostics 166, 324 Render Diagnostics attribute 473 Render Division Levels 514 Render Info Render View 477 Render Layer editor 367 render layers batch 116 command-line 116 control visibility/reflection per layer 120 copy 118 examples 71 layer blend modes 112 layer presets 294 merge when importing files 122 name 119 overriding attributes 109 preview workflow 70 previewing render layers 111 recycle render output for layers 119 workflow 69 Render menu Render View window 474 tearing off 281 Render Mode 289 Render Modes attributes 488 Render Optimizations 470 Aggressive 470

Good 470 Safe 470 Render option Render View window 475 Render Options attributes 387, 396 Render pass set node 503 Render Passes attribute 490 render proxies 243 Bounding Box Update attribute 508 Render Proxy attribute 507 Renderable attribute 506 Render Proxy (Assembly) 310 Render Region option Render View window 474, 478 Render Resolution 88 Render Selected Objects Only option Render View window 474 Render Settings common tab 377 for tessellation 329 Render Settings option Render View window 476 Render Settings window 84, 236 Render Shading, Lighting and Glow attribute 402 Render Shadow Maps attribute 402 Render Stats 511 Render Threads 320, 322, 325 Render utility 128, 133–135, 240–241 Render View about 52 Render View window menus 472 Renderable attribute 351 renderable cameras 167 Renderable Cameras attributes in Render Settings 382 Renderable Scene 309 renderer choosing 12 setting default 12 renderers Maya hardware 5 Maya software 4 mental ray for Maya 173 selecting 11

vector 8 rendering active objects 85 at low-res 128 background problems 144 BOT files 163 cameras 13 command line 262 depth of field 25 errors 166 exporting .mi files 186, 241 extra mental ray render settings 289 fields 91 file formats 53 file output location 64 final rendering 84 final renders 1 Flash 8 frames 91, 131 hardware 3 hardware render settings 454 image output location 88 image resolution 65 layers and passes 301 looping forever 149 MEL scripts 68 mental ray BSP settings 248 mental ray problems 277–278 mental ray render settings 404 multi-processor 132 multiple scenes 135 network 169, 199 network (mental ray) 199 object vibration in 144 over a network 262 previewing 1, 47 problems 166 render settings window 84, 236 resolution 88 safe region for TV 20 single frames 131 software 2 speed 155 speed vs. quality 153 test animation 128 testing 1, 47

Index | 535

tips 2 typical workflow 81 vector 4, 8 vector render settings 459 with command line 133, 239 with IPR 47 with Maya 262 with mental ray 241–242, 262 with Render View 52 with the command line 53, 186 Rendering CPU attribute 325 Rendering Flags Attribute Editor 176 Renumber Frames Using attribute 381 Reset Region Marquee option Render View window 473 resolution image 88 low-res rendering, Render View low-res rendering 128 of rendered images 65 Resolution attribute 487 Image Size attributes 387 Resolution Gate attribute 24 Resolution Gate option 343 Resolution Units attribute Image Size attributes 387 Reuse Existing Dmap(s) 161, 250 Reuse Tessellations attribute 400 RGB 78 RGB (default) attribute 430 RGBA 78 RGBAZ 78 RLA format 57 Roll Scale setting 357 rolling, cameras 18 Root Group Name 311 Rotation type setting 357

S Safe Action option 344 Safe Title option 21, 344 Sample Lock attribute 419 Sampling Mode attribute 417

536 | Index

Save Image option Render View window 472 Save IPR File Render View window 472 Save IPR File option 125 Scale (Caustics) attribute 434 Scale (Global Illumination) attribute 433 Scale (Irradiance Particles) attribute 443 Scale attribute (final gather) 438 Scale setting 356–357 Scanline attribute 407 Scanline Only Rendering 278 Scene Fragment 310 scene views guidelines 24 selecting camera 26 view lighting 126 view shading 126 scenes diagnosing 156 diagnosing (mental ray) 197 finding problems Render Diagnostics 156, 197 framing with camera 30 optimizing 158, 247 rendering multiple 135 Secondary Bounce Scale attribute 438 Secondary Curve Fitting 460 Secondary Diffuse Bounces attribute 438 Secondary Final Gather File attribute 440 secondary tessellation 40 Segments attribute 423 Select Camera 340 Selected Surfaces tessellation 327 Separate Shadow Bsp attribute 422 server 200 server setup 252 service file troubleshooting 284 Set NURBS Tessellation 42 setting 88 setup client 252 server 252 SGI format 58

SGI Movie format (UNIX only) 58 SGI16 format 58 shaders 176 Shading attribute 389 shading networks mental ray for Maya 174 Shading Quality 418 Shading Samples Render Layer Member Overrides 500 Render Stats 513 Shading Samples attribute 389–390 Shading Samples Override Render Stats 513 Shading Samples Override attribute 148 Shadow 176 Shadow attribute 420 Shadow Map Bias 446 shadow mapping 279 Shadow Rays attribute 162, 251 shadows optimizing 161, 250 Shadows (SWF and bitmap formats only) 465 Shadows attribute 394, 420 Shadows Ignore Linking attribute 397, 424, 458 Shadows Obey Light Linking attribute 397, 424, 458 Shadows Obey Shadow Linking attribute 397, 424, 458 Shake attribute 349 Shake Enabled attribute 349 Shake Overscan attribute 349 Shake Overscan Enabled attribute 349 Show Back Faces 465 Show Batch Render 326 Show menu Rendering Flags window 482 Show Region Marquee option Render View window 473 shutter angle 15 Shutter Angle description, for cameras 316 Shutter Angle attribute 353 Shutter Close attribute 426 Shutter Open attribute 426

shutter setting mental ray vs. Maya 427 shutter speed 15 Simple attribute 422 Single Color 461 Size Units attribute Image Size attributes 386 Small Object Culling Threshold attribute 457 Smooth 2D Motion Blur 395 Smooth Alpha 2D Motion Blur 395 Smooth Color 2D Motion Blur 395 Smooth Edge Ratio Set NURBS Tessellation 330 Smooth Polygon Derivatives attribute 450 smooth polygon mesh render 215, 514 Smooth shading Render Layer Member Overrides 498 Render Stats 512 Smooth Value 2D Motion Blur 395 tip, Motion Blur 396 Snap box dolly to camera settings 356 Snapshot in Render View 129–130 Snapshot option Render View window, Render menu 475 SoftImage format 58 software rendering 2 memory and performance 97 Sort attribute 423 Special Effects attributes cameras 353 Specular Render Layer Pass 303 Start Frame attribute Image File Output attributes 87, 381 Image Output Files attributes 486 Start Number attribute 381

Index | 537

Static Object Offset 429 Stepped Tumble camera setting 355 Stereoscopic Edit 33 Registering custom rig 35 Render 34 Scripting 34 stereoscopic camera 14 create 32 stereoscopic cameras custom rig 471 stereo menu 358 String options 272, 306 Subdivision Power attribute 401 subdivision surfaces mental ray for Maya 185 subDs approximation 184 display tessellation 44 obtaining quads for approximation 207 Surface Dolly camera setting 356 surfaces background showing through 144 identical 159, 248 mental ray approximation 184 performance 160, 249 polygonal 50 single-sided 160, 249 tessellation settings 41 troubleshooting 146, 148, 283 Svg Animation (SVG only) 459

T Targa format 58 Task Size 320, 322, 325 tear off menu Render menu 281 television safe region rendering tessellate strategies 43

538 | Index

20

tessellation 146 about 39 display for NURBs 43 display for subDs 44 memory and performance 97 primary 40 problems with 143 secondary 40 span-based 44 strategies for 40 surface types 41 viewing settings 41 vs. approximation 39 when to adjust 39 Tessellation attribute 447 Tessellation Mode 328 tessellation passes about 40 test render 1 Test Resolution 476 Test Resolution option 323 Render View window 127 Texture Compression attribute 456 Texture Map 515–516 Texture resolution menu 485 Textured channel menu 485 textures popping 333 troubleshooting 143 Texturing attribute 489 Threshold Output Settings attribute 352 Threshold attribute 451 Tiff format 59 Tiff16 format 59 tilt, cameras 18 Time Contrast Motion Blur 176, 180 Time Contrast R attribute 429 Time Samples attribute 428 Time slider Hardware Render Buffer 494 Time Slider for tessellation 329 Tonemap Scale 446

Toolbar option Render View window 478 Toxik Export Options (Toxik 2008) 336 Toxik pre-compositing 233, 337, 406 Toxik Scene Settings 334 Toxik User Settings (Toxik 2007) 334 Trace 176 Trace Reflection mental ray 507 Track Geometry setting 355 Track Scale setting 356 tracking, cameras 17 Transform Icons attribute 491 translate polygon meshes as subdivision base mesh primitives 268 Transmit Refraction mental ray 507 Transmit Transparency mental ray 507 transparency channels 67 matte (see Matte Opacity) 90, 237 premultiplication 78 Transparency Based depth Output Settings attributes, for cameras 352 Transparency sorting attribute 455 transparent objects motion blur problems 145 Transparent Shadow maps attribute 455 Traverse (Importons) attribute 437 Triangle (default) attribute 418 troubleshooting 284 caustics 162 displacement maps 147 edges 146 final gather 162 flickering 147 global illumination 162 highlights 148 image quality and render speed 153 motion blur 148 surfaces 148 Tumble Locked camera setting 355 Ortho step camera setting 355

Orthographic views camera settings 355 Stepped camera setting 355 Tumble camera about camera settings 355 Tumble pivot camera setting 355 Tumble scale camera setting 355 Tumble camera about camera settings 355 Tumble pivot Tumble camera setting 355 Tumble Pivot attribute 354 tumble, cameras 17 tuning region 123 TV production safe region rendering 20 Two Color 462

U U Divisions Factor Set NURBS Tessellation 329 U Divisions Factor attribute 146 Undoable Movements attribute 354 Undoable Movements option 340 Update 2D Motion Blur on or off for IPR 476 Update Image Planes/Background option IPR menu 50 Render View window 475 Update Light Glow on or off for IPR 476 Update Shader Glow on or off for IPR 476 Update Shading and Lighting on or off for IPR 476 Update Shadow Maps option IPR menu 50 Render View window 475 Update Toxik 335 Use 2d Blur memory Limit 2D Motion Blur 396 Use all available CPUs 401

Index | 539

Use all available processors attribute 132, 324 Use Chord Height attribute 332 Use Chord Height Ratio 332 Use Custom Extension attribute 87, 381 Use Displacement Bounding Box attribute 400 Use Dmap Auto Focus 161, 250 Use File Cache attribute 399 Use Frame Range for tessellation 328 Use Legacy Maya Base Shaders attribute 451 Use Min Screen attribute Secondary Tessellation Attributes 333 Use Multi Pixel Filter attribute 390 Use Pivot As Local Space attribute 354 Use Preview Level for Rendering 514 Use Radius Quality Control attribute 441 Use Smooth Edge Set NURBS Tessellation 330 Use X- Dmap attribute 250 Use X- Map attribute 161 Use X+ Dmap attribute 250 Use X+ Map attribute 161 Use Y- Dmap attribute 250 Use Y- Map attribute 161 Use Y+ Dmap attribute 250 Use Y+ Map attribute 161 Use Z- Dmap attribute 250 Use Z- Map attribute 161 Use Z+ Dmap attribute 250 Use Z+ Map attribute 161 User Data 263 UVs 50

V V Divisions Factor Set NURBS Tessellation 329 V Divisions Factor attribute 146 vector file formats, bitmap file formats 54 vector renderer 8 Vector Renderer Control 515

540 | Index

vector rendering 4 per-material attributes 99 Render Settings 459 verbosity 177, 251 Verbosity Level 290, 320, 322, 325 Verbosity Level attribute 320, 322, 325 Version Label attribute 381 Vertical Film Aperture attribute (see Camera Aperture attribute) 314 Vertical Film Offset attribute (see Film Offset attribute) 314 Vertical option 344 video 65 frame rendering 65 video fields 66 View (Radii in Pixel Size) 442 mental ray 509 View menu Render View window 473 Visibility Samples 418 Visible 176 Visible in Reflections Render Layer Member Overrides 499 Render Stats 512 Visible in Refractions Render Layer Member Overrides 498 Render Stats 512 Visible In Transparency mental ray 507 visualization IPR rendering 123 rendering 83 visualization, renders 1 Volume Samples Render Stats 514 Volume Samples attribute 409 Volume Samples Override 514 voxels, example of 421

W walk throughs 19 Width attribute Image Size attributes Resolution attributes

386 88

Windows Bitmap image file format 59 Windows setup 252 workflow render layers 69 working with render layers 100 Write ZDepth attribute 487

Z Z buffer channel 79 Z depth channel 79 Zeroth Scanline attribute Zoom Scale setting 356 zooming, cameras 18

144, 392

Y yaw, cameras

18

Index | 541

542

Rendering

Short Description

Description

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