I have an idea for a PI emitter that I wanted to suggest : Footprints / Animal tracks / Vehicle tracks etc ...
I was thinking of (for example) white footprints on a black background that either walk in a line, or maybe in random patterns around the screen, and then gradually fade out.
I was thinking that the output from such an emitter could be used as a bump or displacement map on a moving plane that could be used (E.g. in Vue) to simulate say wet footprints or tracks on the sand and move like a treadmill, so that the footprints remain relatively in-place as the plane moves forward - I don't know if that makes sense?
Footprints are something that are usually hard to create in basic 3D animations, but I think this would work well.
Anyhow - knowing that my ideas are usually better than my efforts - I thought i'd mention it here to see if anyone could do this justice. >8o)
Cool idea. I'm big into using PI for my 3D stuff - as texture maps, bump maps, lighting gels...etc. I even made a tutorial on just that sort of thing which you can find on the wondertouch website tutorial section.