k3d/share/shaders/k3d_orennayar.sl:50:    float alpha, beta, sigma2, cos_phi_diff;
k3d/share/shaders/k3d_orennayar.sl:61:	cos_phi_diff = normalize(Eye-Nf*(Eye.Nf)) . normalize(LN - Nf*(LN.Nf));
k3d/share/shaders/k3d_orennayar.sl:67:	if (cos_phi_diff >= 0)
k3d/share/shaders/k3d_orennayar.sl:71:	L1 = Cs * (cos_theta_i * (C1 + cos_phi_diff * C2 * tan(beta) +
k3d/share/shaders/k3d_orennayar.sl:72:				  (1 - abs(cos_phi_diff)) * C3 * tan((alpha+beta)/2)));
k3d/share/shaders/k3d_orennayar.sl:74:			  (1 - cos_phi_diff*(4*beta*beta)/(PI*PI)));
