   3D Textures?
  I was wondering if anyone has actually used them and of what good use are they? I remember vaguely using it in a Maya class I took not to long ago but it seemed pointless because we could have just used a 2d texture to apply it to a sphere. I hadn't bothered to think about it much since and when I did google I just got a long mathmatical representation but not really any uses on them. I just started learning from a book on game programming. Can someone give an example in game or 3d modeler to use these maybe one is the MRI scaning not that I will anytime soon.   
  How about rendering clouds? I vaguely remember something along those lines. Here's a google search result:click;  Thanks for that example lightbringer. Maya (Unlimited Version) seems to have something simliar (Fluid Effects or somthing) except I don't think its a 3D texture though they have it. I guess just for curiosity reasons I was looking for info on it.   