Validation of variable resolution BSDFs in Radiance

In this document results of the validation of the "Variable Resolution BSDF" approach as presented at the 10th International Radiance Workshop (G.Ward, A.McNeil, "A Variable-resolution BSDF Implementation") are presented.

Variable-resolution BSDFs are generated with genBSDF for the RADIANCE native materials plastic, trans, and glass (isotropic) and plastic2 and trans2 (anisotropic). Both, the maximum resolution (1024 x 1024 patches or 4096 x 4096 patches) as well as the number of specular samples (16 or 64) are varied.

The resulting data is reduced with rttree_reduce at various degrees (0%, i.e. no reduction, 95%, i.e. reduction by approximately 95%, and 99%, i.e. only about 1% of data left).