An Efficient SAH-Based KD-Tree Construction Algorithm for Ray Tracing

KD-Tree is an important accelerating structure for ray-tracing based realistic rendering. How to construct kd-tree efficiently is very crucial for ray tracing performance. In this paper, we present a fast construction algorithm. It is based on SAH cost estimation function and adopts a clever way to keep sorting order without sorting every time. Thus we reduce the complexity to O(NlogN), which is the asymptotic lower bound for building kd-trees.