Chapter 13. Generating Soft Shadows Using Occlusion Interval Maps
William Donnelly University of Waterloo
Joe Demers NVIDIA
In this chapter we present a technique for rendering soft shadows that we call occlusion interval mapping. Occlusion interval maps were used to produce soft shadows in the NVIDIA GeForce FX 5900 demo “Last Chance Gas.” See Figure 13-1. We call the technique occlusion interval mapping because it uses texture maps to store intervals that represent when the light source is visible and when it is occluded. In situations that satisfy the algorithm’s requirements, occlusion interval mapping allows you to achieve impressive visual results at high frame rates.
Figure 13-1. The “Last Chance Gas” Demo
The Gas Station
One of the goals of ...
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