Asynchronous BVH Construction for Ray Tracing Dynamic Scenes on Parallel Multi-Core Architectures

Abstract

Recent developments have produced several techniques for interactive ray tracing of dynamic scenes. In particular, bounding volume hierarchies (BVHs) are efficient acceleration structures that handle complex triangle distributions and can accommodate deformable scenes by updating (refitting) the bounding primitive without restructuring the entire tree. Unfortunately, updating only the bounding primitive can result in a degradation of the quality of the BVH, and in some scenes will result in a dramatic deterioration of rendering performance. The typical method to avoid this degradation is to rebuild the BVH when a heuristic determines the tree is no longer efficient, but this rebuild results in a disruption of interactive system response. We present a method that removes this gradual decline in performance while enabling consistently fast BVH performance. We accomplish this by asynchronously rebuilding the BVH concurrently with rendering and animation, allowing the BVH to be restructured within a handful of frames.