[vtkusers] mixing actors in vtkImageViewer2

[Tatti Emanuele]

Hi all,
i want to mix volume and polydata in vtkImageViewer2
The docs say:
"Any portions of your geometry that are in front of the displayed slice 
will be visible; any portions of your geometry that are behind the 
displayed slice will be obscured."
but i would like to emulate the viewer input behaviour without using the 
class vtkImageActor; i tried setting manually the camera clipping range 
and i partially succeded but on Slice 0 only the ImageActor is visible.
Is there any method to do that?