Jacobian: Support for a given point on a link body

[Tadinu]

Hi,
Jacobian in MuJoCo supports calculation on how a "spatial frame anchored at the given point will translate and rotate if we make a small change to the kinematic configuration".
Namely, mj_jac describes "the local linear relationship between the degrees-of-freedom and a given point".
It would be great if it is supported in Genesis, for instance, to be used in collision constraint formulation for an LSQP controller, like in mink
#1050

[duburcqa]

what about RigidEntity.get_jacobian ? It is used in the example examples/rigid/diffik_controller.py, and internally for RigidEntity.inverse_kinematics.

[duburcqa]

I think Genesis exposes all the necessary features that are required by mink.

[Tadinu]

Can you elaborate, Is that RigidEntity.get_jacobian only considers an existing link as input? How would it be used to get one for a point on the link body as noted above? Thanks

[duburcqa]

I should be straightforward to generalize it, and it is a very reasonable feature request. Could you create an issue to summarize all these information? Then I would create the PR next week.

[Tadinu]

Thanks a bunch, here is the issue #1050