Ambience

Ambient light simulates indirect lighting.

It is basically a constant level of lighting that's added to a surface's color, regardless of orientation.

The ambient lighting effect is the product of the light source's ambient color and the material's ambient color.

glLightfv(GL_LIGHT0, GL_AMBIENT, [0.1, 0.1, 0.1, 1])

glMaterialfv(GL_FRONT, GL_AMBIENT, [1, 1, 1, 1])

There is also a global source of ambient light, controlled by glLightModel

glLightModelfv(GL_LIGHT_MODEL_AMBIENT,[.1, .1, .1, 1])