[ODE Middleware) – in here you’ll find my code that contains (among other things) ODE Area Triggers, which might be what you’re looking for. Or at least it might provide you with some kind of inspiration, or a starting point.
Note that I’m not using Panda ODE’s AutoCollide there, because I’ve found it (including it’s collision callbacks) not flexible enough.
Also, I’ve been unable to achieve Area Trigger functionality with AutoCollide at all, because I couldn’t figure out how to make it stop creating collision joints between what was supposed to be a trigger, and the geoms inside. As a result, the geoms just popped out of the trigger, as one would expect. Have you been able to do that with autocollide by creating a geom with a body and no mass?
Anyway, I think for such stuff using ODE’s mechanisms more directly, as I did it in my code, works better and provides far more flexibility that Panda’s automatic systems.
Hope that was somewhat helpful.