Enhancing time and space efficiency of kd-tree for ray-tracing static scenes

In the ray-tracing community, the surface-area heuristic (SAH) has been employed as a de facto standard strategy for building a high-quality kd-tree. Aiming to improve both time and space efficiency of the conventional SAH-based kd-tree in ray tracing, we propose to use an extended kd-tree representation for which an effective tree-construction algorithm is provided. Our experiments with several test scenes revealed that the presented kd-tree scheme significantly reduced the memory requirement for representing the tree structure, while also increasing the overall frame rate for rendering.