An ambient light illumination model

Abstract

In this paper we introduce an empirical ambient light illumination model. The purpose of the development of this model is to account for the ambient light in a more accurate way than it is done in Phong illumination model, but without recoursing to such expensive methods as radiosity. In our model we simulate the indirect diffuse illumination coming from the surfaces of the scene by direct illumination coming from the distributed pseudo-light source. The estimation of indirect illumination is based on the concept of obscurance coefficients that resemble the integrated weighted form-factors computed for some vicinity of a given point. The same idea is used to account illumination of a given point (patch) from light sources. This illumination is computed as a sum of direct illumination calculated using the standard local reflection model and empirically estimated indirect illumination based on the same obscurance concept.