A shading method for computer generated images

A shading method for computer generated images is developed that provides benefits of both ray tracing and radiosity methods. Diffuse reflection behavior is taken from the radiosity approach, while specular reflection and transparency are based on ray tracing methods. Distributions of sample rays are traced to calculate approximate geometric form factors used in the radiosity solution for shading free form surfaces. The resulting shaded images include the effects of color bleeding between diffuse surfaces, soft shadows, caustics, and attenuations in reflection and transparency based on the Fresnel reflection law.