“A Ray tracing algorithm for progressive radiosity” by Wallace, Elmquist and Haines

  • ©John R. Wallace, Kells A. Elmquist, and Eric Haines




    A Ray tracing algorithm for progressive radiosity



    A new method for computing form-factors within a progressive radiosity approach is presented. Previously, the progressive radiosity approach has depended on the use of the hemi-cube algorithm to determine form-factors. However, sampling problems inherent in the hemi-cube algorithm limit its usefulness for complex images. A more robust approach is described in which ray tracing is used to perform the numerical integration of the form-factor equation. The approach is tailored to provide good, approximate results for a low number of rays, while still providing a smooth continuum of increasing accuracy for higher numbers of rays. Quantitative comparisons between analytically derived form-factors and ray traced form-factors are presented.


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