slides

Shading Rate
• This is probably the second most critical factor in the speed performance of
RenderMan (exceeded only by the resolution).
• This is due to two factors.
• First, it governs how often the shading language interpreter runs. Smaller
numbers mean the shaders must be evaluated at more places on the surface of
the primitives.
• Second, it governs how many polygons (micropolygons) are passed through the
hidden-surface algorithm.
• Smaller numbers mean more micropolygons, requiring more hidden-surface
evaluation and more memory to store temporary results.
• The end result of all this is that doubling the Shading Rate usually gets you
nearly twice the rendering speed. Pretty good!
Saturday, 23 October 2010