BounceBox - Using webcam + coloured token to control a crosshair

A simple project I finished a while ago. More details including link to source and compilation instructions here:, but I’ve copied over the basic description below:

The user interacts with BounceBox by moving a coloured token around in front of a webcam to position a crosshair. If this crosshair is positioned over one of the coloured spheres shown above and the user presses a key, the sphere is pushed and bounces around inside the box, causing it to light up wherever the sphere hits it.

Note that I wrote this using the Linux v007 pre-release and haven’t tested it on anything other than an Ubuntu 11.10 machine, so I’m sorry if it takes a little effort to compile. Hopefully it should still be a useful example for someone.