This operator generates a two sided surface. The front facing surface and the back facing surface are shaded with different input colors.
No lighting calculation is done in this operator, so either pipe the resulting color into the Diffuse (and Ambient) inputs of the Lighting Model operator, or ensure that the incoming colors are pre-lit.
If the Direction from Eye to Surface (
I) or the Surface Normal (
not connected, the global variables by the same names will be used
instead. Typically, you will not touch
N unless you had applied
additional displacement to the surface using an operator such as Bump Noise. If you need to access the global variables directly, they are
available from the Global Variables operator.