What best to pick and move actor?

I have seen vtkInteractorStyleTrackballActor approach. But can’t use two styles vtkInteractorStyleTrackballActor and vtkInteractorStyleTrackballCamera at same time. What will be best way to achieve the movement of an actor after picking it with click? Adding keypress observers?

How to get mouse clicked event info? (Not mouse down and up)

And how to judge if mouse clicked within renderer?

Successfully achieved all my requirements with idea of ObserverMemberFunction example. :ok_hand: