@brief Return the bodies that this joint connects.
@ingroup joints
@param index return the first (0) or second (1) body.
@remarks
If one of these returned body IDs is zero, the joint connects the other body
to the static environment.
If both body IDs are zero, the joint is in `limbo'' and has no effect on
the simulation.
@brief Return the bodies that this joint connects. @ingroup joints @param index return the first (0) or second (1) body. @remarks If one of these returned body IDs is zero, the joint connects the other body to the static environment. If both body IDs are zero, the joint is in `limbo'' and has no effect on the simulation.