I got the projector sized to the IR touch frame. I made a desk inset for it and a wood overlay to sit on top.

The overlay makes the section non-interactive (it had to be an overlay bc the IR beams need to get from one-side to the other).

I want the non-interactive section for object capture. I have the overhead camera sized to the screen to but if I put an object down within the touch frame it will disrupt it.

I think it might be an interesting pattern to play with. Having one adjustable (even removable) non-interactive section and the other half have full touch. It's a pattern I was previously doing with hand tracking for button pressing but this gets me actual touch (versus checking boundaries with hand-tracking).

I'm not sure how practical this all is - but I'm always interested in where capabilities can be split. So where normally you have a touch screen now I have the touch and screen part separate. Mostly I'm recombining them to be close to a conventional touch screen but I also have the ability to add some wrinkles.

Another rough video of overhead camera capture: