Improved Monte Carlo form factor integration

Form factors are used in radiosity image synthesis to describe the fraction of diffusely reflected light leaving one surface and reaching another. They incorporate fundamental geometric properties of interacting surfaces used for light transfer computation.Many numerical applications such as realistic image synthesis require accurate and simple formula for the form factors from small oriented differential areas (treated as a point with a normal) to different geometrical objects; a disk was used in this paper. The exact analytic solution for the general point-to-disk form factor integral is used to develop more accurate numerical techniques for form factor integration for surfaces commonly in use. The improvements are illustrated with realistic image synthesis.