Ambient Light

Left: No ambient light

Middle: Default ambient light

Right: User-adjusted ambient light

Ambient light is the general light that illuminates the entire scene. It has a uniform intensity and is uniformly diffuse. It has no discernible source and no discernible direction.

By default, there's a small amount of ambient light in every scene. If you examine the darkest shadows on your model with the default ambient light setting, you can still make out the surface because it's lit by the ambient light. Shadows in your scene will not appear any darker than the ambient light color, which is why you usually keep ambient light set to black (or a very dark color).

Typically, the best practice in lighting is to set your ambient lighting to black, set up all your lights, and then decide at the end if you need to increase the ambient light.

If you use photometric lights and a radiosity solution, ambient light is accurately calculated. The other advanced lighting option, light tracing, also generates ambient lighting.