For the last couple of months i have been working on a multitouch table together with Ole Kristensen for Vision4. It has been a project i have worked on on very part time, but it has been funny to investigate all the techniques and materials i needed to do it. And now we have made a presentationvideo of the table. It is very much a technical preview, so the demos are more to demostrate what is possible. I have builded the table myself (in my garden), and the code is primary done by me, with some help from Ole Kristensen.
The surface is a thin glass plate with a Lee filter 400 underneath to project on. In the bottom of the box there is an ordinary surveillance camera with a IR filter in (so it only sees infrared light, and not visible light), and a BenQ short-throw projector and a lightbulb wrapped in some color filters. it does give some visible red light, but its not very much. This technique is called DI (Diffused Illumination).
The tracking of the fingers with the camera is done by the opensource application tBeta, and send with OSC to my own openframeworks application that does all the graphical work. I might release the code at some point.
If you have any suggestions or questions, feel free to ask me!