k3d/share/shaders/k3d_grids.sl:6:float K_diffuse=0.381; 
k3d/share/shaders/k3d_grids.sl:97:Ci = (blend_val*G1L1_Ct+(1-blend_val)*G1L2_Ct) * (ambientcolor * K_ambient * ambient() + K_diffuse * diffuse(G1_Nf)) + 
