A physically accurate reflectance model combining reflection and diffraction

Reflectance properties express how objects in a virtual scene interact with light. They control the appearance of the object: whether it looks shiny or not, it has a metallic or plastic appearance. The reflectance model (BRDF) is essential for photorealistic pictures. Measured reflectance provide high realism, at the expense of memory cost. Parametric models are compact, but it is difficult to find the right parameters from measured reflectance. In this research report, we show that two different physical phenomena are present in measured reflectance: reflection and diffraction. Taking both into account, we present a reflectance model that is compact and a very good approximation of measured reflectance. Designers can act on model parameters, related to surface properties, to create new materials.Analyse des opérateurs de transport lumineux et application