Back in 2007 when I was just starting Music Technology, I was introduced to a project and instrument called the Reactable.  The Reactable (google it) is an awesome multi-touch instrument that is controlled by placing objects on a table.  On each object there is a unique symbol which is read by a camera, processed and the XY position and rotation are calculated.  These bits of data can then be used and manipulated to control music.

It took until the second half of 2009 before I was able to have a crack at building something similar.  The plan was to build a multi-touch table using open source software.  Pure Data as well as reacTIVision were used and a working instrument formed.  Below is the video documentation for one of subjects I used it for, including the final performance.  The final Pure Data files can be downloaded from here by following this link.

The following are links to the software and well springs of information that I used in the creation of this projects.

http://puredata.info/

http://reactivision.sourceforge.net/

http://nuigroup.com/

Let me know if you have a go at making something similar.

As a final goodie, here is a link to the paper that I wrote the documents the process of creating the instrument.

Multi-touch Technologies.pdf