Research

Real-Time Global Illumination using Precomputed Light Field Probes

"Real-Time Global Illumination using Precomputed Light Field Probes"
Morgan McGuire (NVIDIA), Mike Mara (Stanford), Derek Nowrouzezahrai (McGill University), David Luebke (NVIDIA), in ACM Symposium on Interactive 3D Graphics and Games, February 2017
Research Area: 3D Graphics
Author(s): Morgan McGuire (NVIDIA), Mike Mara (Stanford), Derek Nowrouzezahrai (McGill University), David Luebke (NVIDIA)
Date: February 2017
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Abstract: We introduce a new data structure and algorithms that employ it to compute real-time global illumination from static environments. Light field probes encode a scene’s full light field and internal visibility. They extend current radiance and irradiance probe structures with per-texel visibility information similar to a G-buffer and variance shadow map. We apply ideas from screen-space and voxel cone tracing techniques to this data structure to efficiently sample radiance on world space rays, with correct visibility information, directly within pixel and compute shaders. From these primitives, we then design two GPU algorithms to efficiently gather real-time, viewer-dependent global illumination onto both static and dynamic objects. These algorithms make different tradeoffs between performance and accuracy. Supplemental GLSL source code is included.