Exemplar Based Non-parametric BRDFs

Realistic rendering of computer modeled three dimensional surfaces typically involves building a parameterized model of the bidirectional reflectance distribution function (BRDF) of the desired surface material. We present a technique to render these surfaces with proper illumination and material properties using only a photograph of a sphere of the desired material under desired lighting conditions. Capitalizing on the fact that the geometry of the material in the photograph is known, we sample pixels of the sphere's reflectance to create photo-realistic renderings of computer models with the same material properties. The reflectance is sampled using texture synthesis techniques that compensate for the fact that very little of the BRDF observed in the photograph is known. The technique uses the limited observations of the function to create a plausible realistic rendering of the surface that can be composited onto a background plate easily