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 1.9-2.1x 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.
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