2008
Use Fast Rasterizer (Rapid Motion Blur) When on, uses a fast rasterizer
method to generate the first generation of rays to trace. This can improve
rendering speed. Default=off.
This option works well with object motion blur, and also with scenes that
have no motion blur.
The following settings are available for the fast rasterizer:
■ Samples per Pixel Controls the number of samples per pixel used by the
fast rasterizer method. More samples result in greater smoothness, at a cost
of render time. Range=1 to 225. Default=16.
■ Shades per Pixel Controls the approximate number of shading calls per
pixel. Greater values result in more accurate renderings, at a cost of render
time. Range=0.1 to 10000 (ten thousand). Default=1.0.
NOTE mental ray provides a Time Samples setting specifically for motion blur in
the fast rasterizer. When Use Fast Rasterizer is on, the Camera Effects rollout >
Time Samples on page 6092 label changes to Time Samples (Fast Rasterizer) to
indicate that this version of Time Samples is now in effect.
Ray Tracing group
Enable When on, mental ray uses ray tracing to render reflections, refractions,
lens effects (motion blur and depth of field), and indirect lighting (caustics
and global illumination). When off, the renderer uses the scanline method
only. Ray tracing is slower but more accurate and more realistic. Default=on.
To render reflections, refractions, depth of field, and indirect lighting (caustics
and global illumination), Ray Tracing must be enabled.
Use Autovolume When on, uses the mental ray autovolume mode. This lets
you render nested or overlapping volumes such as the intersection of two
spotlight beams. Autovolume also allows a camera to move through the nested
or overlapping volumes. Default=off.
To use Autovolume, Ray Trace must be on, Scanline must be off, and the
shadow mode must be set to Segments. (You set the shadow mode on the
Shadows And Displacement rollout on page 6114 .) If these conditions aren't
met when you click to turn on Autovolume, an alert warns you about this,
and gives you the option of making the appropriate setting changes.
6120 | Chapter 18 Rendering