[vtkusers] same camera on different viewpoints

[Sebastien Valette]

Hi!

>Hi Mark,
>I have used the "ren2->SetActiveCamera(ren1->GetActiveCamera())" approach
>only on small test programs and I have got no crashes. On production
>applications the pair vtkOrientationMarkerWidget / vtkAxesActor was
>sufficient to me as I only needed a smaller viewport showing axes "perfectly
>alligned" with the object shown in the main viewport.

>It would be interesting to know if anybody on the list has had crash
>problems by sharing camera pointers among renderers.

I also use this shared pointer approach to link several RenderWindows. For me, it works very well, except one reproducible bug: Assuming that there are 2 RenderWindows, each one having one interactor (Interactor1 and Interactor2), if I launch the interaction with interactor 1, and then finish the interaction on Window2 (by pressing "e"), the programm crashes instantly.

Sebastien