On Importance of Scene Structure for Hardware-Accelerated Ray Tracing

Ray tracing is typically accelerated by organizing the scene geometry into an acceleration data structure. Hardware-accelerated ray tracing, available through modern graphics APIs, exposes an interface to the acceleration structure (AS) builder that constructs it given the input scene geometry. However, this process is opaque, with limited knowledge and control over the internal algorithm. Additional control is available through the layout of the AS builder input data, the geometry of the scene structured in a user-defined way. In this work, we evaluate the impact of a different scene structuring on the run time performance of the ray-triangle intersections in the context of hardware-accelerated ray tracing. We discuss the possible causes of significantly different outcomes (up to 1.4 times) for the same scene and identify a potential to reduce the cost by automatic input structure optimization.