Radiance Cache Splatting: A GPU-Friendly Global Illumination Algorithm

Abstract

Fast global illumination computation is a challenge in several fields such as lighting simulation and computergenerated visual effects for movies. To this end, the irradiance caching algorithm is commonly used since it provides high-quality rendering in a reasonable time. However this algorithm relies on a spatial data structure in which nearest-neighbors queries and data insertions are performed alternately within a single rendering step. Due to this central and permanently modified data structure, the irradiance caching algorithm cannot be easily implemented on graphics hardware. This paper proposes a novel approach to global illumination using irradiance and radiance cache: the radiance cache splatting. This method directly meets the processing constraints of graphics hardware since it avoids the need of complex data structure and algorithms. Moreover, the rendering quality remains identical to classical irradiance and radiance caching. Our renderer shows an implementation of our algorithm which provides a significant speedup compared to classical irradiance caching.