Autodesk 12812-051462-9011 User Guide 3 - Page 774

Mask Only Outputs only the mask color (see following) in the specified objects' locations; this is very fast. Use this if you only want to locate the objects in the scene. Rays not hitting any objects return the Background color, and rays hitting any object not in the subset return the Other Objects color. Mask Color The color returned for specified objects when Mask Only is on. Color of Background The color returned for the background when Mask Only is on. Color of Other Objects The color returned for non-specified objects when Mask Only is on. Calculate FG on All Objects (Entire Image) Determines whether the final gather (FG) preprocessing should apply to all objects, or only those in the subset. Because FG blends neighboring FG samples, a given object might use information in FG points coming from nearby objects not in the subset. This is especially true if the objects are coplanar. Therefore it is advised to let the FG prepass "see" the entire scene. Turning off this option and creating FG points only for the subset of objects is faster, but there is a certain risk of boundary artifacts, especially in animations. If the scene uses a saved FG map, this option can be left off. Output Shaders Motion Vector Export (mi) Render Setup dialog > Renderer panel > Camera Effects rollout > Camera Shaders group > Output button > Material/Map Browser > Motion Vector Export (mi) NOTE Shaders appear in the Browser only if the mental ray renderer is the currently active renderer. This shader is intended for those who wish to do compositing work before applying motion blur, or to use a specific third-party motion-blur shader. Its purpose is to export motion in pixel space (mental ray's standard motion vector format is in world space) encoded as a color. mental ray Shaders | 6029