A comprehensive physical model for light reflection

TLDR

The paper introduces a general reflectance model for computer graphics. The model, grounded in physical optics, analytically describes specular, directional diffuse, and uniform diffuse reflection as functions of wavelength, incidence angle, two roughness parameters, and refractive index, while ensuring self‑consistency of polarization, masking/shadowing, and energy across a wide range of materials and surface finishes. The model’s predicted reflectance distributions agree well with experimental measurements.

Abstract

A new general reflectance model for computer graphics is presented. The model is based on physical optics and describes specular, directional diffuse, and uniform diffuse reflection by a surface. The reflected light pattern depends on wavelength, incidence angle, two surface roughness parameters, and surface refractive index. The formulation is self consistent in terms of polarization, surface roughness, masking/shadowing, and energy. The model applies to a wide range of materials and surface finishes and provides a smooth transition from diffuse-like to specular reflection as the wavelength and incidence angle are increased or the surface roughness is decreased. The model is analytic and suitable for Computer Graphics applications. Predicted reflectance distributions compare favorably with experiment. The model is applied to metallic, nonmetallic, and plastic materials, with smooth and rough surfaces.