[vtkusers] add same actor to multiple render windows

[John Hunter]

I have two different views of medical image data: image plane widgets
in one renderer and surface reconstructions in another.  I mark
objects in the scene with glyphs (sphere actors).

Each of the different render windows is a vtkRenderWindowInteractor.

I find that if I add the same vtkActor to the two renderers, the image
plane widgets start to act funny: sometimes they spontaneously
disappear from the scene (I can bring them back, eg, by pressing 'x'
and then 'x') but they'll disappear again.  Sometimes parts of them
will disappear, eg, the line borders around the plane widget.

I've narrowed this down to adding the same actor to the two different
renderers.  If I comment out the AddActor line in the surface
rendering window, the IPW problem goes away in the other renderer.  If
I add a different glyph/sphere actor to the surface rendering window
with the same properties - radius, color, location, etc, the IPW
problem in the other renderer also the problem goes away.

Is this to be expected?  Should adding the same actor to multiple
renderers work?  It would be nice to use the same actor so that
changes in the properties in one window (eg color, size) would be
reflected in the other w/o minimal work.

Thanks,
John Hunter


VTK-4.4 using vtk.gtk.GtkGLExtVTKRenderWindowInteractor

hunter:~/python/projects/eegtools> uname -a
Linux hunter.paradise.lost 2.4.20-8smp #1 SMP Thu Mar 13 17:45:54 EST 2003 i686
i686 i386 GNU/Linux