hbfm

So today I walked through this tunnel at work that connects these two buildings. Closed off behind a sort of fence on one side of the tunnel are the steam pipes for the heat. Since this is an old building, these pipes haven't been cleaned in forever. The dust was probably 3-5mm thick in the thick patches. As I walked beside these pipes, I noticed that the wind of people passing, or something, had made ripples, whirls, and dunes of this dust. Rather than be grossed out by this, I wondered how I could duplicate the look in a raytracer.

Suggestions are welcome. I haven't used any since about POV-RAY 1.5 or 2, so some general suggestions like "height fields" are just fine.