Schlick's approximation
Encyclopedia
In 3D computer graphics
, Schlick's approximation is a formula for approximating the bidirectional reflectance distribution function (BRDF) of metallic surfaces. It was proposed by Christophe Schlick to approximate the contributions of Fresnel terms in the specular reflection
of light from conducting surfaces.
According to Schlick's model, the specular reflection coefficient
R is given by
where
is half the angle between the incoming and outgoing light directions, and 
is the reflectance at normal incidence (i.e., the value of the Fresnel term when 
).
3D computer graphics
3D computer graphics are graphics that use a three-dimensional representation of geometric data that is stored in the computer for the purposes of performing calculations and rendering 2D images...
, Schlick's approximation is a formula for approximating the bidirectional reflectance distribution function (BRDF) of metallic surfaces. It was proposed by Christophe Schlick to approximate the contributions of Fresnel terms in the specular reflection
Specular reflection
Specular reflection is the mirror-like reflection of light from a surface, in which light from a single incoming direction is reflected into a single outgoing direction...
of light from conducting surfaces.
According to Schlick's model, the specular reflection coefficient
Reflection coefficient
The reflection coefficient is used in physics and electrical engineering when wave propagation in a medium containing discontinuities is considered. A reflection coefficient describes either the amplitude or the intensity of a reflected wave relative to an incident wave...
R is given by
where
is half the angle between the incoming and outgoing light directions, and is the reflectance at normal incidence (i.e., the value of the Fresnel term when ).See also
- Phong reflection modelPhong reflection modelThe Phong reflection model is an empirical model of the local illumination of points on a surface...
- Blinn-Phong shading model
- Fresnel equationsFresnel equationsThe Fresnel equations , deduced by Augustin-Jean Fresnel , describe the behaviour of light when moving between media of differing refractive indices...