SnapInteractors can snap to poses provided by SnapInteractables.
SnapInteractors select and unselect in response to a PointableElement. SnapInteractors hover when the PointableElement has selecting pointers and snap to the best SnapInteractable pose when the PointableElement has no more selecting pointers.
The Unity Rigidbody most relevant to the current instance.
The role this Rigidbody plays varies according to the implementing type; for example, an HandGrab.HandGrabInteractor may use a Rigidbody for collision detection when grabbing.
