The effectiveness of the ReSTIR technique when ray tracing a voxel world

Abstract

Recent work by Bitterli et al. combines previous techniques such as weighted reservoir sampling and resampled importance sampling into an algorithm called ReSTIR capable of rendering of scenes illuminated by many dynamic lights in real-time. We introduce Voxel ReSTIR, an algorithm derived from ReSTIR tailored to voxel worlds, and compare it to ReSTIR. We explore the performance of the algorithms in different settings. We show that that both our point light and area light algorithms perform better in terms of speed and quality than ReSTIR in the same setting. Our algorithm is suitable for GPU implementation and we are able to achieve near real-time performance on consumer level hardware.