[vtkusers] two renderer in renderwindow

[Thomas Faust]

Hi VTK users.

A while ago (with an older version of vtk) I wrote a application, that handles 
two renderer in one renderwindow. A main renderer and a renderer that holds 
three arrows to see the rotation of the volume in the other renderer.

This is what i did:

-- snip --
renderwindow->SetNumberofLayers( 2 );
renderwindow->AddRenderer( axesRenderer );
axesRenderer->SetLayer( 0 );
axesRenderer->SetBackground( 1.0, 1.0, 1.0 );
axesRenderer->SetViewport( 0.0, 0.8, 0.2, 1.0 );
  // 20% in the upper left corner

renderwindow->AddRenderer( mainRenderer );
mainRenderer->SetLayer( 1 );
mainRenerer->SetBackground( 1.0, 1.0, 1.0 );
-- end snip --

I worked fine until I updated the the current VTK version.

Now I get a very ugly behavior when rotating the model. The background don't 
get white again and when interacting with the model, it leaves prints 
wherever it was drawn.

Did somebody saw the same behavior?
What is the right way to display two renderer correctly?