I've been trying to add some fog to a 3D environment in AfterEffects, but continue to get negative results. Is there anyone who could bear with me and give a smooth step-by-step as to how to do this?
You didn't mention this explicitly, but I'm going to venture a guess: The Fog 3D effect confuses a lot of people because they don't realize that it's a 3D Channel effect and therefore depends on having 3D channel information (specifically z depth information) about the layer's footage item to work. This effect isn't for generically creating 3D fog; it's for compositing fog into a 3D scene. You have to supply your own fog layer and a layer with depth information.