Thanks for the reply,
I've given this a go, but I can't get it to behave as I wish.
While I can use the gear to set the desired angle, if I have any gravity applied it doesnt seem to apply enough force to actually move anything. For example, if you imagine a ragdoll which has fallen onto it's legs on the ground, if I tell it to bend it's knee where you might expect it to straighten it's leg and raise it's body slightly, nothing happens.
I have set the biasCoeff, the maxBias and maxForce, but my understanding is that none of these affect the torque being applied, just limit the effect it would have.
How is the force being applied being calculated? Can I have control over that, or am I better off manually applying a torque and relying on the pivot joint to ensure the correct behavior?
Would it be possible to get a bit more documentation and maybe some worked examples of the constraints in the wiki docs? They are very light on, at this point it isn't really clear to me what joint I should use to get a particular outcome, nor what I can and can't control about them. I found the youtube clip very helpful for understanding the constraints in general, but in this specific case I am pretty much at a loss at how to achieve what I want.