Photometric model of diffuse surfaces described as a distribution of interfaced Lambertian facets.
The Lambertian model for diffuse reflection is widely used for the sake of its simplicity. Nevertheless, this model is known to be inaccurate in describing a lot of real-world objects, including those that present a matte surface. To overcome this difficulty, we propose a photometric model where the surfaces are described as a distribution of facets where each facet consists of a flat interface on a Lambertian background. Compared to the Lambertian model, it includes two additional physical parameters: an interface roughness parameter and the ratio between the refractive indices of the background binder and of the upper medium. The Torrance-Sparrow model--distribution of strictly specular facets--and the Oren-Nayar model--distribution of strictly Lambertian facets--appear as special cases.
PHYMAT (Laboratoire de Physique des Matériaux) UMR 6630, Université de Poitiers, Boulevard Marie et Pierre Curie, SP2MI-Téléport 2-BP 30179, F-86962, Futuroscope Chasseneuil Cedex, France. lionel.simonot@univ-poitiers.fr
Lionel
L
Simonot