Thanks Hifire.
I just looked up some pics from the party (not sure why I didn't do that initially) you can see what I mean here
The visuals were much cooler than what these pics suggest later in the night.

It does seem to be basically projectors firing at the cloth, but if I knew what it is called I could research the specifics further. I was just thinking about it recently and was wondering how hard it would be to implement as the 3d effect looked much cooler than just a projector on a wall.
Check it ****s.