Up: up A Fast and Accurate Light Reflection Model
Previous: previous Physical Parameters
Next: next Specular component

Components of the BRDF

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].

Converted to HTML by Stephen H. Westin <swestin@earthlink.net>
Last modified: Mon Sep 5 22:08:04 EDT 2011
Valid HTML 4.01!