relating to illumination properties, e.g. using a reflectance or lighting model

albedo the proportion of the incident light or radiation that is reflected by a surface diffuse reflection diffuse reflections reflection having the property that incident light rays are scattered in many different directions illumination cone illumination cones representation of a set of all possible images of a convex Lambertian surface created by varying the strength and direction of an arbitrary number of light sources at infinity Lambertian model model according to which the radiant intensity or luminous intensity observed from an ideal diffusely reflecting surface or ideal diffuse radiator is directly proportional to the cosine of the angle θ between the direction of the incident light and the surface normal (I = I 0 cos(θ)) reflectance effectiveness of a surface in reflecting radiant energy, component of the response of the electronic structure of the material to the electromagnetic field of light, and is in general a function of the frequency, or wavelength, of the light, its polarisation and the angle of incidence specular reflection specular reflections mirror-like reflection spherical harmonics special functions defined on the surface of a sphere, generally used to model the reflectance properties of a three-dimensional [3D] surface