An empirical BSSRDF model

摘要: We present a new model of the homogeneous BSSRDF based on large-scale simulations. Our captures appearance materials that are not accurately represented using existing single scattering models or multiple isotropic (e.g. diffusion approximation). use an analytic function to 2D hemispherical distribution exitant light at point surface, and table parameter values this computed uniformly sampled locations over remaining dimensions domain. This is expressed in elliptic coordinates has six parameters which vary smoothly with surface position, incident angle, underlying optical properties material (albedo, mean free path length, phase relative index refraction). agrees well measured data, compact, requiring only 250MB represent full spatial- angular-distribution across wide spectrum materials. In practice, rendering requires about 100KB BSSRDF.