Joshua Bainbridge

Sorted Shading for Uni-Directional Pathtracing

Thesis Sorted Shading for Uni-Directional Pathtracing

Abstract

Physically based models for light transport using ray tracing have become standard practice in industry as a result of changing demands and computational power. This approach simplifies pipelines and naturally solves many issues found with rasterized methods at the expense of computation. There has been much research and development into reducing such cost although there are other factors that contribute to latency, such as memory access and cache coherence of large production data sets. With ever increasing scene complexity, out of core access to geometry and texture data become an issue. This thesis investigates a current solution to this problem as described by Eisenacher et al. (2013) in combination with other well established optimisations for production rendering. This solution involves sorting rays and hit points into batches that are streamed from disk into main memory, allowing for optimal ray traversal and perfectly coherent shading. As a result we negate the need for such methods as irradiance caching that compromise artistic intent and limit scalability.