I am trying to use gazebo::physics::Joint::GetVelocity() function. But for constructor of gazebo::physics::Joint(), we need inputs as ; (BasePtr _parent). Can you tell me how can I get these parameters ? Thank you .

You can refer to this link for this function : http://osrf-distributions.s3.amazonaws.com/gazebo/api/dev/classgazebo_1_1physics_1_1Joint.html

I asked something similar in this question http://answers.gazebosim.org/question/8768/how-to-get-velocity-of-a-joint-using-api/ but did not get any reply. You can refer to here also.

Thank you .