Data Structures for Interpolation of Illumination with Radiance and Irradiance Caching

Irradiance and radiance caching are important algorithms for solving the light transport problem in realistic image synthesis. They both require geometric search data structures for efficient rendering. Our goal was to improve the caching algorithms by improving these data structures. We have implemented 6 different data structures for irradiance caching, 2 previously used and 4 newly adapted to the problem. Our testing showed that multiple-reference data structures offer the best traversal performance at the cost of higher memory consumption. For interpolation on glossy surfaces we have implemented the spatial directional radiance caching. Instead of modifying its data structures we have created a novel radiance caching algorithm by merging its spatial and directional interpolation phases, creating the unified radiance cache.