Very preliminary question: wondering what the chances of integrating something like this into Vuo, as a plugin, I guess. Or other possibilities?
The last time I used Box2D was a raw kludge, and it was someone else's role on the team to do that part -- two laptops, laptop 1 with a max/Jitter patch for IR tracking and sending Box2D data as OSC via ethernet to laptop 2 running graphics out of Quartz Composer. (I could and did at times run everything on one laptop, distance from performer+tracking to control booths created the need for two laptops.)
This, by the way, was a show for kids. DIY all the way -- the tracking was an IR bulb inside a pingpong ball with a battery pack attached to a trombone slide with electrical tape. Camera was a hacked PlayStation Eye camera. (It would be nice to have a more elegant solution for this setup.) We did our little interactive media show at grade schools as well as for full orchestra. Box 2D was driving a starry sky, and the trombonist could swing his trombone around and the stars would react with physics. Effective, kids loved it, it was magic to them. We also made "magic wands" for the kids, with pingpong ball trackers attached to little wand handles.
I am currently in discussions about how to revive some of this. (Another thing was a pre-show drawing table where kids would draw or move objects around on a plexiglass window, a webcam below would record to video, then we would use the videos as a section of the graphics for the music performance that followed. Satisfying for all to see the videos placed immediately into a performance context.)
My experience thus far with Vuo is that it might take a while (for me) to get something working, but the results could be solid. I have not dug in much yet to 2.2, looks great, esp. for app building! (Part 2 of this would be to have a separate "controller" app running alongside projected graphics -- I have seen in the forum here that others also use this approach. Part 3 would be to output a video recording of show graphics, hopefully not choking a 2014 MBP.)