CS 269S, Winter 2014: Theory Seminar
Bren Hall, Room 1423, 1pm
March 14, 2014:

Stackless Multi-BVH Traversal for CPU, MIC and GPU Ray Tracing

Tamir Husain

Presenting a paper by Attila T. Áfra and László Szirmay-Kalos

Stackless traversal algorithms for ray tracing acceleration structures require significantly less storage per ray than ordinary stack-based ones. This advantage is important for massively parallel rendering methods, where there are many rays in flight. On SIMD architectures, a commonly used acceleration structure is the MBVH, which has multiple bounding boxes per node for improved parallelism. It scales to branching factors higher than two, for which, however, only stack-based traversal methods have been proposed so far. In this paper, we introduce a novel stackless traversal algorithm for MBVHs with up to four-way branching. Our approach replaces the stack with a small bitmask, supports dynamic ordered traversal, and has a low computation overhead.