アイテム詳細

要旨

A major reason for the recent advancements in ray tracing performance is the use of optimized acceleration structures, namely kd-trees based on the surface area heuristic (SAH). Though algorithms exist to build these search trees in $O(n\log n)$, the construction times for larger scenes are still high and do not allow for rebuilding the kd-tree every frame to support dynamic changes. In this paper we propose modifications to previous kd-tree construction algorithms that significantly increase the coherence of memory accesses during construction of the kd-tree. Additionally we provide theoretical and practical results regarding \emph{conservatively} sub-sampling of the SAH cost function.