Proximity Radiosity : Exploiting Coherence to Accelerate Form Factor Computations
This paper introduces a new acceleration principle for the zonal method. The core concept resides in exploiting the coherence that exists between form factors of two close voxels (or patches). Primarily, we dissociate the radiometric part of the form factors form the geometrical part, the remaining geometrical expressions including volume integrals can be then developed with the Green-Ostrogradski theorem in terms of double surface integrals. These new expressions are less complex and allow us to divide computational time by a factor of about 4. Secondary, we show how all voxels in the neighborhood of a given “reference” voxel, have form factors (with another patch or voxel) that are weighted sums of the reference voxel form factor and a series of associated integrals of generalized orthogonal polynomials. Subsequently, calculation time decreases while a control of the generated error is maintained.
KeywordsForm Factor Zonal Method Global Illumination Volume Form Factor Reference Patch
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- Arquès D., Michelin S., Improving the zonal method through the use of series developments to approximate volume/volume form factors, WSCG’96, 1996, Plzen, Czech Republic, pp. 21–30.Google Scholar
- Cohen M. F., Wallace J. R., Radiosity and realistic images synthesis, Acad. Press, 1993.Google Scholar
- Gradshteyn I. S., Ryzhik I. M., Table of integrals, series and products, Academic Press, 1980.Google Scholar
- Gortler S.J., Schroder P., Cohen M.F., Hanrahan P., Wavelet radiosity, Siggraph’93, Computer Graphics annual Conference series, 1993, pp. 221–230.Google Scholar
- Siegel R., Howell J. R., Thermal radiation heat transfer, third edition, Hemisphere, 1992.Google Scholar
- Sillion F. X., Puech C., Radiosity and global illumination, 1994, Morgan Kaufmann Publishers.Google Scholar
- Sillion F.X., A unified hierarchical algorithm for global illumination with scattering volumes and Objects clusters, IEEE Trans, on Visual, and CG, vol 1(3), pp. 240–254.Google Scholar
- Zatz H.R., Galerkin Radiosity, Siggraph’93, Computer Graphics annual Conference series, 1993, pp. 213–220.Google Scholar