I'm currently doing a little experiment with displacements and procedural textures. I've created a scene that's starting to look pretty cool, and wanted to add some low-lying fog (using a procedural volume object) in there to increase the sense of scale.
As you can see, it looks pretty bad where the fog clips the sides of the "buildings". I've tried using an ambient occlusion node to fade off the fog near geometry, so you get a smoother blend, but I can't seem to get it to recognise geometry outside itself.
Anyone got any ideas on how to get this to work better?