npetit
Here's a quick example showing how you might setup some conetwist constraints to use with the RBD Bullet Solver SOP.
Notice I'm only driving a few of the conetwist constraint properties via attributes on the constraint prims.
If you want different settings per constraint for other properties, you'll need to add them as attributes and make sure their default values (which will be multiplied by the prim attributes) on the RBD Bullet Solver are set to 1.
The tricky thing with the conetwist constraint would have to be the motor_target. It's not very intuitive in the slightest. While the parameter on both the RBD Bullet Solver SOP and the ConeTwist ConRel DOP specify a motor_targetr vector param, you need to set a quaternion motor_target attribute. This attribute needs to be updated at every timestep, so make sure you add it to the list of constraint attributes to be updated by the RBD Bullet Solver.
Thanks, npetit! Just before finding this, I managed to get something in that worked however seeing your motor setup has more implementation possibilities. Thank you so much! I converted your VEX to vop with success but whatever my setup is doing, I supposed I need more work getting that working.