SurfaceColor

• directives give surface properties that determine the effect of simulated illumination on polygons and other surfaces.

• directives can appear inside FaceForm directives.

• Explicit color directives such as RGBColor override previous specifications, so that {..., RGBColor[...], Polygon[...]} specifies an explicit color for a polygon, independent of lighting.

• will override previous explicit color directives, and specifies that subsequent surfaces should be colored using simulated illumination.

• is equivalent to SurfaceColor[GrayLevel[1], GrayLevel[0], GrayLevel[0]].

• If no directive is given, surface are assumed to be white diffuse reflectors of light, obeying Lambert's law of reflection, so that the intensity of reflected light is times the intensity of incident light, where is the angle between the direction of the incident light and the surface normal. When , there is no reflected light.

• SurfaceColor[GrayLevel[a]] specifies that surfaces should act as diffuse reflectors, but with albedo a. The intensity of reflected light is therefore a times the intensity of the incident light, multiplied by , and is of the same color.

• SurfaceColor[RGBColor[r, g, b]] specifies that the red, green, and blue components of the reflected light should be respectively r, g, and b times those of the incident light, multiplied by .

• The second element in specifies a specular reflection component. scol must be a GrayLevel, Hue, or RGBColor specification. The color components of scol give the fractions of each color component in the incident intensity, which are reflected in a specular way by the surface.

• The parameter n gives the specular exponent. The intensity of specularly reflected light at angle from the mirror-reflection direction falls off like as increases. It is zero when .

• For real materials, n is typically between about 1 and a few hundred. With a coarse polygonal mesh, however, values of n below 10 are usually most appropriate. The default value for n is .

• Mathematica implements a version of the Phong lighting model, in which the intensity of reflected light is given schematically by .

• The intensities of light from glow and diffuse and specular reflection are added linearly for each color component. The final color shown for a particular polygon is the sum of contributions from each light source, and from ambient light.

• does not apply to Line and Point objects.