Precomputed Local Radiance Transfer for Real-Time Lighting Design

Anders Wang Kristensen, Tomas Akenine-Möller, and Henrik Wann Jensen

To appear in Proceedings of ACM SIGGRAPH 2005, Los Angeles, USA, July 31 - August 4, 2005

This paper introduces a new method for real-time relighting of scenes illuminated by local light sources. We extend previous work on precomputed radiance transfer for distant lighting to local lighting by introducing the concept of unstructured light clouds. The unstructured light cloud enables a compact representation of local lights in the model and real-time rendering of complex models with full global illumination due to local light sources. We use simplification of lights, and clustered PCA to obtain a compressed representation. When storing only the indirect component of the illumination, we are able to get high quality with only 8-16 lighting coefficients per vertex. Our results demonstrate real-time rendering of scenes with moving lights, dynamic cameras, glossy materials and global illumination.

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