Vray — Materials

[ f_oren = \frac\rho\pi \left( A + B \cdot \cos(\phi_i - \phi_o) \cdot \sin(\alpha) \cdot \tan(\beta) \right) ]

For conductors (metals), V-Ray uses the ( \tilden = n + ik ), where ( k ) is the extinction coefficient: vray materials

[ f_r = f_diffuse + f_specular ] For perfectly rough surfaces, V-Ray defaults to the Lambertian model (constant albedo). However, for rough, clay-like materials, V-Ray implements the Oren-Nayar model, which accounts for retro-reflection: [ f_oren = \frac\rho\pi \left( A + B

[ \mathbbV[L] \propto \frac1N \sum_k=1^N \fracf(\omega_k)p(\omega_k) \cdot \texttrunc_L(\textFTT(u,v)) ] V-Ray implements the Oren-Nayar model