A realistic material model for reflectance simulation

In order to simulate the correct behavior of light incident on a material, we must first understand the different interactions not only between the light and the surface of the material but also between the light and the inner structure of the material itself. Physical measurement is a way to record a material's behavior, but is limited to pre-existing objects and measurement conditions. Therefore, we have developed a multiresolution material model, generically describing its inner structure thanks to a microelement distribution. Then we use this model in a virtual measurement bank in order to record its response to an incident luminous radiance. Once obtained, this directional reflectance is stored, compressed and used in a rendering model such as ray-tracing or radiosity.