Accelerated entry point search algorithm for real-time ray-tracing

Abstract

Traversing an acceleration data structure, such as the Bounding Volume Hierarchy or kD-tree, takes a significant amount of the total time to render a frame in real-time ray tracing. We present a two-phase algorithm based upon the Multi Level Ray-Tracing Algorthm (MLRTA) for finding deep entry points in these tree acceleration data structures in order to speed up traversal. We compare this algorithm to a base MLRTA implementation. Our results indicate an across-the-board decrease in time to find the entry point and deeper entry points. The overall performance of our real-time ray-tracing system shows an increase in frames per second of up to 36% over packet-tracing and 18% over MLRTA. The improvement is algorithmic and is therefore applicable to all architectures and implementations.