|Up:||A Fast and Accurate Light Reflection Model|
The BRDF can be divided into three components:
|ρbd = ρbd,sp + ρbd,dd + ρbd,ud||(3)|
where ρbd,sp gives the specular component, ρbd,dd gives the directional diffuse component, and ρbd,ud gives the uniform diffuse component. The components are shown schematically in Figure 5.
Figure 5: Components of the BRDF
We would like to examine the reflected radiance dIr, which can be expressed as a product of the BRDF and the incident energy flux:
|dIr||=||ρbd • dEi|
|=||(ρbd,sp + ρbd,dd + ρbd,ud) • dEi|
|=||dIr,sp + dIr,dd + dIr,ud||(4)|
The general light reflection model that we will use [HE91] assumes a Gaussian, isotropic rough surface. The model is based on wave optics and accounts for diffraction and scattering effects. The model provides closed-form analytic expressions for the specular, directional diffuse, and uniform diffuse components of the BRDF. Any equations not given here are available in [HE91].
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