Here's a demo of a program I wrote last year. It's a more sophisticated version of the Processing software that ran Urban Echo (vimeo.com/468417 ). Basically it unites a bunch of great examples from the OpenFrameworks forums and mixes in some Box2d physics and OpenCV for "automatic" obstacle detection (it works really well when the façade is simulated with black paper on a white wall :)) . This software is the basis for some real-time, large-scale, architecturally-integrated, performance software we use over at minneapolisartonwheels.org. It's designed to be used with three big GRL projector trikes we built. Anyway, many thanks to all those who contributed code on the forums ... knowingly or unknowingly. Also ... excuse the length. May be worth skipping ahead a bit ...

P.S. I recently ported this program (including Box2d) to run in a native Max/MSP/Jitter environment and it will be released soon with a bunch of other stuff like it at minneapolisartonwheels.org.