[vtkusers] Move vtkActor2D with mouse

[Enzo Matsumiya]

Hi,

I have a vtkActor2D which is a vtkSphere cut with a vtkPlane, so it's actually a circle.
I want to be able to move this actor with the mouse. I could do it using the picker, but since the line is very thin, it's very hard do click on it.

How can I implement some kind of "threshold" area to enable selecting the actor and move it with the mouse?
Kind of how vtkResliceCursorWidget or vtkDistanceWidget implements it.


Thanks!