[vtkusers] how to turn OffScreenRendering on?

[Mark Wyszomierski]

Hi,

I wanted to do some offscreen rendering. I loaded a volume up, stuck
it in a render window, added an interactor and orientation widget
(which moves with camera changes).

I set OffScreenRenderingOn() in the render window, but it still
appears - I guess because it has an interactor attached to it?

Is there anyway to force the vvtk render window to stay hidden?

Thanks,
Mark