Automatic Bounding of Programmable Shaders
for Efficient Global Illumination

Edgar Velázquez-Armendáriz Cornell University
Shuang Zhao Cornell University
Miloš Hašan Cornell University
Bruce Walter Cornell University
Kavita Bala Cornell University


ACM SIGGRAPH Asia 2009 (December 2009)


      This paper describes a technique to automatically adapt programmable shaders for use in physically-based rendering algorithms. Programmable shading provides great flexibility and power for creating rich local material detail, but only allows the material to be queried in one limited way: point sampling. Physically-based rendering algorithms simulate the complex global flow of light through an environment but rely on higher level information about the material properties, such as importance sampling and bounding, to intelligently solve high dimensional rendering integrals.

      We propose using a compiler to automatically generate interval versions of programmable shaders that can be used to provide the higher level query functions needed by physically-based rendering without the need for user intervention or expertise. We demonstrate the use of programmable shaders in two such algorithms, multidimensional lightcuts and photon mapping, for a wide range of scenes including complex geometry, materials and lighting.


Paper PDF (~2.5MB)


This work was supported by NSF CAREER 0644175, NSF CPA 0811680, NSF CNS 0403340, and grants from Intel Corporation and Microsoft Corporation. The first author was also supported by CONACYT-Mexico 228785. The third author was partly funded by the NVIDIA Fellowship. The Eucalyptus Grove and Kitchen environment maps are courtesy of Paul Debevec (