“Precomputed Light Sets for Fast High Quality Global Illumination”

Instant Radiosity [Keller 1997] is an elegant algorithm to approximate global illumination by a number of Virtual Point Lights (VPLs) that are generated by a random walk starting from the light sources (Figure 1a). For complex settings however hundreds or even thou- sands VPLs are required and all these VPLs need to be evaluated and their visibility calculated during computation of each pixel in order to minimize artifacts and to obtain smooth shadows. Ray tracing is well suited for the visibility determination [Wald et al. 2002] as the high number of lights complicate the use of shadow maps due to the huge memory consumption.
In this sketch we propose a technique to significantly reduce the number of VPLs to be considered for each pixel by determining the visibility and illumination information in a preprocessing step. Using our method we can quickly produce high quality global illumination renderings even from scenes with complex illumination.

Keller, A. 1997. Instant Radiosity. Computer Graphics (Proceedings of ACM SIGGRAPH), 49–56.
Wald, I., Kollig, T., Benthin, C., Keller, A., and Slusallek, P. 2002. Interactive Global Illumination using Fast Ray Tracing. Rendering Techniques, 15–24. (Proceedings of the 13th Eurographics Workshop on Rendering).