Quote Originally Posted by Midgardsormr View Post
In the 3d rendering world, we call that ambient occlusion. Where two surfaces are close together, such as internal corners or creases, they create a very subtle shadowing. The outer glow that is so popular to put around map objects is an exaggeration of this effect that helps to make the objects seem more a part of the environment.
That explains a lot. I do tend to exaggerate my shadows.