Efficient Spectral Rendering on the GPU for Predictive Rendering

Abstract

Current graphic processing units (GPU) in conjunction with specialized APIs open the possibility of interactive path tracing. Spectral rendering is necessary for accurate and predictive light transport simulation, especially to render specific phenomena such as light dispersion. However, it requires larger assets than traditional RGB rendering pipelines. Thanks to the increase of available onboard memory on newer graphic cards, it becomes possible to load larger assets onto the GPU, making spectral rendering feasible. In this chapter, we describe the strengths of spectral rendering and present our approach for implementing a spectral path tracer on the GPU. We also propose solutions to limit the impact on memory when handling finely sampled spectra or large scenes.