Here, the bidirectional scattering distribution function is used for locations on the surface of objects, and the scattering coefficient at and the phase function are used for those inside the medium. is a generalized geometric term. Display Formula
(8)where is a geometric term. Display Formula
(9)with unit normal of the surface at . is a transmittance that describes the attenuation when light passes through the medium. Display Formula
(11)where is the extinction coefficient at vertex .