Phong illumination model
Phong approximation of surface reflectance
•Assume
reflectance is modeled by three components
–Diffuse
term
–Specular
term
–Ambient
term (to compensate for inter-reflected light)
L, N, V unit vectors
Ie = outgoing radiance
Ii = incoming radiance
Ia = ambient light
ka = ambient light reflectance factor
(x)+ = max(x, 0)
