Advanced Micro Devices, Inc.
MECHANISM FOR SUPPORTING DISCARD FUNCTIONALITY IN A RAY TRACING CONTEXT

Abstract:

Described herein is a technique for performing ray tracing. According to this technique, instead of executing intersection and/or any hit shaders during traversal of an acceleration structure to determine the closest hit for a ray, an acceleration structure is fully traversed in an invocation of a shader program, and the closest intersection with a triangle is recorded in a data structure associated with the material of the triangle. Later, a scheduler launches waves by grouping together multiple data items associated with the same material. The rays processed by that wave are processed with a continuation ray, rather than the full original ray. A continuation ray starts from the previous point of intersection and extends in the direction of the original ray. These steps help counter divergence that would occur if a single shader program that inlined the intersection and any hit shaders were executed.