cmarble - Simulate a veined marble surface
Surface "cmarble" "Ka" n "Ks" n "Kd" n "roughness" n "specularcolor" c "veining" n
float Ka=0.1, Ks=0.4, Kd=0.6, roughness=0.1, veining=1 color specularcolor=[1 1 1]
This shader is very similar to the blue_marble shader in The RenderMan Companion, except that it produces a marble that consists of colored veins on a white background with some greyish mottling. The vein color is determined by the current surface color. The parameter veining controls the frequency of veins in the marble:
The parameters Ka,Ks and Kd have the usual meanings of ambient, specular and diffuse reflective intensities, respectively. roughness and specularcolor control the sharpness and color of the specular highlight. higher values produce more and narrower veins.
Pixar Animation Studios