k3d/share/shaders/k3d_superplank.sl:108:  float fresnelKr, fresnelKt;	/* Fresnel reflection coefficients */
k3d/share/shaders/k3d_superplank.sl:297:  fresnel(IN, Nf, 1 / eta, fresnelKr, fresnelKt, R, T_dummy);
