GLOSSARY
Rendering shows the effect of a pale pink 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.
As a 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.
Often, 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 apply general lighting.