[vtkusers] Combining vtkImageplaneWidget with vtkImageTracer ROI extraction capabilities

[Flo]

Dear all:

I'm struggling to combine the interesting ROI freehand drawing  
extraction of vtkImageTracer with the interesting cursor and plane  
handling of vtkImagePlaneWidget.

What I try to achieve is :
- Load and Render the vtkImagePlaneWidget
- Interact the way I want with it

then

- WHEN the X key is pressed, to add the ROI abilities of ImageTracer  
to my ImagePlane.

I manage to have one or the other but only separately - When I mixed  
them in such ways I always have a crash of a black image.

Did anybody try to do such things ? Is this actually possible ?

regards,

Flo.