A year spent in artificial intelligence is enough
to make one believe in God

Concept 4.4 : Material - Emissivity
===================================

Idea:
=====
GLfloat mat_emiss[] = {red, green blue, alpha};
glMaterialfv(GL_FRONT_AND_BACK, GL_EMISSION, mat_emiss);
makes an object appear to be giving off light of that 
color.

This feature is used mostly to simulate lamps and other
light sources eg. the sun.