I'm currently studying other people's XML files for MuJoCo and I've noticed something that struck me. In my model, when loading it into simulate.cpp, hinges are automatically acted on by gravity and arms and such limply fall down to the ground. Interestingly in the models I'm studying, hinges are not acted on by gravity and they exhibit a sort of stickiness: pulling down on them makes them move correctly but when released they return back to their initial position. How do I go about mimicking this behavior? I've tried playing around with solimplimit which seems like it'd be related to this (the degree of limp-ness) but this had no effect whatsoever. Any ideas? I'm pretty confident to upper torso of the included humanoid.xml also exhibits this behavior.
So it seems this was an issue of scale - everything with dampness and armature were correctly setup, my meshes just needed to be scaled by 0.1