Right now I'm experimenting with Bullet, having used ODE for several years for robotics simulation.
One of the things I have in my codebase is a powered slider, a "piston" of sorts. For example, I have simulated some walkers using something like pneumatic pistons for leg articulation. I'm looking over the btGeneric6DofConstraint and btSliderConstraint and can't find any straightforward way to treat them as motors. They seem passive only.
Now, I recognize I could carefully tune the softness and other parameters of their limits, and emulate a powered piston by moving those limits. But that seems a little crude. Is there some way I'm missing to directly cause the two attached bodies to push apart as if the constraint were powered?
I see that btHingeConstraint has a method for setting a target velocity, so I'm wondering if I'm simply missing an equivalent for the slider or 6Dof.