Is your feature request related to a problem? Please describe.
Hi, is there a way to implement a "sticky gripper" in maniskill? i.e. create a kinematic constraint when making contacts? Thanks.

Describe the solution you'd like
I think all I need to do is to create a fixed link between the target joint and the gripper finger?
In ManiSkill, here is what we did:

parent = env.agent.finger1_joint.articulation.get_builder().create_link_builder()
child = env.target_joint.articulation.get_builder().create_link_builder(parent)
child.set_joint_properties('fixed', limits=[], pose_in_parent=sapien.core.Pose(p=[0, 0, 0], q = [0, 0, 0, 0]), pose_in_child=sapien.core.Pose(p=[0, 0, 0], q = [0, 0, 0, 0]),\
                               friction = 1, damping = 1)

but it had no visible effect on the environment

Additional context
basically it is a gripper that upon contacting the object, it creates a kinematic constraint that never lets go of the object (analogous to a suction gripper). The core question is how to create a fixed kinematic constraint between the gripper and the target.