METHOD AND APPARATUS FOR DETERMINING ACCURATE AREA LIGHT ILLUMINATION USING ELLIPSOID BASED FUNCTIONS

摘要

A glossy part of a radiation coming from a surface illuminated by area light source(s) (21) having source surface(s) (A) bounded by edge curves (210) is estimated, by determining integrand function(s) representative of that glossy part, the latter corresponding to an integration of the integrand function along the edge curves. In this respect, the integrand function(s) is/are approximated by means of at least one ellipsoid-based-peak-shape function(s) having a null first derivative in the integration domain bounds, and the glossy part is computed from analytical expressions associated with integrations of the ellipsoid-based-peak-shape function(s) along the edge curves weighted by a factor for best fitting in the tail.