[vtkusers] TrackBallActor and camera movement

[Totte Karlsson]

On 2/12/2015 1:17 PM, Totte Karlsson wrote:
> Hi,
> I have a question on how to move the camera while being in 
> TrackBallActor mode.
>
> Particularly, I would like the camera to be moved, while in 
> TrackBallActorMode, as if being in TrackBallCamera mode, if and only 
> if the user clicks the mouse without selecting an actor.
>
> Would there be an easy way to achieve that?
> Would it be possible to derive from the interactor styles and then 
> switch between them in corresponding event functions?
>

Found out that achieving the above  is possible when deriving from 
vtkInteractorStyleTrackballCamera and then do picking in the OnMouse event,
like in this example 
http://www.itk.org/Wiki/VTK/Examples/Cxx/Interaction/Picking