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

Autor: László Szirmay-Kalos, Attila T. Áfra
Rok vydání: 2013
Předmět:
Zdroj: Computer Graphics Forum. 33:129-140
ISSN: 0167-7055
DOI: 10.1111/cgf.12259
Popis: 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. We also present efficient implementation techniques for recent CPU, MIC Intel Xeon Phi and GPU NVIDIA Kepler architectures.
Databáze: OpenAIRE