TouchDesigner: Projection Drawing

I was feeling itchy to get a projector out and try out a little webcam motion tracking with Cache and Difference TOPs (fed into a Feedback loop of course) to see if I could finagle a little real-time projection drawing using only a pin light (or is it pen light?) on a 3D surface. I also was prepping to teach a workshop on Projection Mapping, so truth be told there was a little bit of convenience-based project going on here.

 

I ended up having to use the Stoner tool to warp the output of the drawing to match up as best I could. Otherwise, I'd get 5-10 lines all drawing on feedbacking off each other turning into glitchy rainbow chaos!

 

I know, I love rainbow chaos - but it wasn't what I was going for.

 

I think this concept would work really well projected onto a flat surface like a wall. Unfortunately, the 3D perspective makes for a difficult time.