Is it possible to determine the total illumination of a particular polygon with the given light sources?
I truly acknowledge that Mathematica is not supposed to do this modeling, but it is what is at fingertips for the time being and, according to the Documentation Center, Mathematica somehow does it when rendering a 3D object:
"Directional lighting" simulates a uniform field of light pointing in the given direction. The Wolfram Language adds together the light from all of these sources in determining the total illumination of a particular polygon.
The only thing I want is to take out that brightness number from processing of graphics and now I wonder does anybody know how to accomplish that?