The surface of all SWR reflectances and spectral simulation
Color and Visual Appearance. The Metallic Look

In this section, we discuss theoretical aspects of the interaction of light with a smooth or rough metal surface and their direct application to realistic visualization. The metallic material is assumed to be defined by its complex refractive index and surface state. We assume that spectral effects due to the nature of the material can be separated from geometrical effects due to its surface state . Roughness then appears, in this approximation, as a term independent of the nature of the material and acting as a "potentiometer" on the clarity of the observed surface.