A Reflectance Model for Computer Graphics

Robert L. Cook, Kenneth E. Torrance


A new reflectance model for rendering computer sythesized images is presented. The model accounts for the relative brightness of different materials and light sources in the same scene. It describes the directional distribution of the reflected light and a color shift that occurs as the reflectance changes with incidence angle. A method for obtaining the spectral energy distribution of the light relfected from an object made of a specific real material is presented, and a procedure for accurately reproducing the color associated with the spectral energy distribution is discussed. The model is applied to the simulation of a metal and a plastic.

Paper (PDF)

Published in Transactions on Graphics, Vol. 1, No. 1, January 1982.