For most objects the color comes from a Material node. The dominant color is
in the diffuseColor field. The color is specified in RGB format with each component
between 0 1nd 1. (0,0,0) is black and (1,1,1) is white.
For zero and one dimensional objects such as points, lines and curves, the color
is determined by the emissiveColor field.
The ambientIntensity field sets the amount of ambient light, and has the effect of
brightening or darkening all objects, independent of their position.
The emissiveColor field specifies the color of the light that is given off by the
object. In this example, the diffuseColor is yellow and the emissiveColor is red.
The transparency field contains a number between 0 and 1. If the transparency
is 0, the object is completely opaque, while if the transparency is 1, the
object is invisible.
