Autodesk 12812-051462-9011 User Guide 3 - Page 897

NOTE Image motion blur doesn't work for NURBS objects that are animated so their tessellation (surface approximation on page 2554) changes over time. This happens when sub-objects are animated independently of the top-level NURBS model on page 8061. Nor does image motion blur work on any of the following: ■ Anything with an Optimize. ■ Any primitive with animated segments. ■ MeshSmooth of any type with a "Smoothness" value (under iterations) other than 1. ■ MeshSmooth on polygons with Keep Faces Convex on. ■ Anything with Displacement Material. In general, if you have objects with changing topology, use scene or object motion blur rather than image motion blur. Apply Turns image motion blur on or off globally for the entire scene. Any objects that have their Image Motion Blur property set are rendered with motion blur. Duration Specifies how long the "virtual shutter" is open. When this is set to 1.0, the virtual shutter is open for the entire duration between one frame and the next. The higher the value, the greater the motion blur effect. Apply to Environment Map When set, image motion blur is applied to the environment map as well as to the objects in the scene. The effect is noticeable when the camera orbits. The environment map should use Environment mapping: Spherical, Cylindrical, or Shrink-Wrap. The image motion blur effect doesn't work with Screen-mapped environments. Transparency When on, image motion blur works correctly with transparent objects that overlap. Applying image motion blur to transparent objects can increase rendering time. Default=off. Auto Reflect/Refract Maps group Rendering Iterations Sets the number of inter-object reflections in non-flat automatic reflection maps. Although increasing this value can sometimes enhance image quality, it also increases rendering time for reflections. 6152 | Chapter 20 Rendering