Efficient incoherent ray traversal on GPUs through compressed wide BVHs

We present a GPU-based ray traversal algorithm that operates on compressed wide BVHs and maintains the traversal stack in a compressed format. Our method reduces the amount of memory traffic significantly, which translates to 1.9--2.1× improvement in incoherent ray traversal performance compared to the current state of the art. Furthermore, the memory consumption of our hierarchy is 35--60% of a typical uncompressed BVH. In addition, we present an algorithmically efficient method for converting a binary BVH into a wide BVH in a SAH-optimal fashion, and an improved method for ordering the child nodes at build time for the purposes of octant-aware fixed-order traversal.