[vtkusers] Syncing Render Windows -- vtkRenderWindowInteractor slows down interaction rate.

[pjtr hahn]

Hi,

I try to sync the camera interaction in two different windows. While
trying this I've noticed strange behaviour of vtkRenderWindow and
vtkRenderWindowInteractor I don't understand.

1.) When I create two different render windows + interactors without
my own syncing stuff -- just plain VTK -- then, the first time I try
to interact with one of the windows their is a large lag in response
time.
After the first lag the window is responsive as usual until I change
to the other window and visa versa. It seams something complicated
get's initialized each time.

--  there is a huge lag then changing focus of interaction from one
window to another.

2.) When I enable my sync mechanism to sync camera movement of both
windows I get that lag in every frame of course.

3.) Since my sync calls call vtkRenderWindow::Render() and not
vtkRenderWindowInteractor::Render() I tried to omit the
vtkRenderWindowInteractor of the second Window.
This is working fine.

I don't understand the connection of vtkRenderWindowInteractor and
vtkRenderWindow in this case. Why is the Interactor slowing down calls
to vtkRenderWindow::Render()?

Any ideas?

regards,

Peter