[vtkusers] vtkActor2D and opacity

[Helmut Muehl]

Hi there,

i try to change the opacity of a vtkActor2D.
One of you gave me the tip to use the vtkWindowToImageFilter
and the vtkImageBlend class. I do so and i actually can change the
opacity but I'm not able to display the result in my renderwindow.
My code is:

vtkWindowToImageFilter *w2if = vtkWindowToImageFilter::New();
vtkImageBlend *ibl = vtkImageBlend::New();

w2if->SetInput(interactor1->GetRenderWindow());

ibl->SetInput(1, w2if->GetOutput());
ibl->SetOpacity(1, opacity);

// at this point something like ...ibl->GetOutput(1) is missing
   to update my actor in the renderwindow.

Hope somebody has an idea what to do.

Best regards
Helmut