Dynamic Diffuse Global Illumination with Ray-Traced Irradiance Fields

We show how to compute global illumination efficiently in scenes with dynamic objects and lighting. We extend classic irradiance probes to a compact encoding of the full irradiance field in a scene. First, we compute the dynamic irradiance field using an efficient GPU memory layout, geometric ray tracing, and appropriate sampling rates without down-sampling or filtering prohibitively-large spherical textures. Second, we devise a robust filtered irradiance query, using a novel visibility-aware moment-based interpolant. We experimentally validate performance and accuracy tradeoffs and show that our method of dynamic diffuse global illumination (DDGI) robustly lights scenes of varying geometric and radiometric complexity. For completeness, we demonstrate results with a state of the art glossy ray tracing term for sampling the full dynamic light field and include reference GLSL code.