Real-Time Global Illumination
using Precomputed Light Field Probes

ACM SIGGRAPH Symposium on Interactive 3D Graphics and Games
Best Presentation Award

Morgan McGuire, NVIDIA and Williams College
Michael Mara, NVIDIA and Stanford University
Derek Nowrouzezahrai, McGill University
David Luebke, NVIDIA

Paper (36 MB PDF)
Video results (37 MB MP4)
I3D Slides (43 MB PDF)
GDC Slides (45 MB PDF)
Video results (YouTube)
Reference implementation


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.


Selected Images


  author = {Morgan McGuire and Michael Mara and Derek Nowrouzezahrai and David Luebke},
  title = {Real-Time Global Illumination using Precomputed Light Field Probes},
  month = {February},
  booktitle = {I3D 2017},
  day = {25},
  year = {2017},
  pages = {11},
  url = {}