Fast, effective BVH updates for animated scenes

Bounding volume hierarchies (BVHs) are a popular acceleration structure choice for animated scenes rendered with ray tracing. This is due to the relative simplicity of refitting bounding volumes around moving geometry. However, the quality of such a refitted tree can degrade rapidly if objects in the scene deform or rearrange significantly as the animation progresses, resulting in dramatic increases in rendering times and a commensurate reduction in the frame rate. The BVH could be rebuilt on every frame, but this could take significant time. We present a method to efficiently extend refitting for animated scenes with tree rotations, a technique previously proposed for off-line improvement of BVH quality for static scenes. Tree rotations are local restructuring operations which can mitigate the effects that moving primitives have on BVH quality by rearranging nodes in the tree during each refit rather than triggering a full rebuild. The result is a fast, lightweight, incrementa...

• Type: Journal
• Year: 2012
• Where: SI3D
• Authors: Daniel Kopta, Thiago Ize, Josef B. Spjut, Erik Brunvand, Al Davis, Andrew E. Kensler
• Keywords: Computer Graphics, Relative Simplicity, SI3D 2012, Tree Quality, Volume Hierarchies