Self shadowing and local illumination of randomly rough surfaces

This paper develops an analytic model for self shadowing and local illumination of rough surfaces. The surface is assumed homogeneous, isotropic, and smooth microscopically, with a Gaussian height field. The total reflection is decomposed into single and multiple scattering. A shadowing factor is derived as a function of surface roughness, and color variation due to multiple scattering is described. This model is compared to previous models and the effects of surface roughness are studied via rendered images.