## Diffuse-reflectance model for smooth dielectric surfaces

A reflectance model that accurately predicts diffuse reflection from smooth inhomogeneous dielectric surfaces as a function of both viewing angle and angle of incidence is proposed. Utilizing results of radiative-transfer theory for subsurface multiple scattering, this new model precisely accounts for how incident light and the distribution of subsurface scattered light are influenced by Fresnel attenuation and Snell refraction at a smooth air--dielectric surface boundary. Whereas similar assumptions about subsurface scattering and Fresnel attenuation have been made in previous research on diffuse-reflectance modeling, the proposed model combines these assumptions in a different way and yields a more accurate expression formore »