I fixed the problem by replacing vtkSmartPointer by a real pointer and it works Now. I still don't know what's wrong with the smartpointers. -- View this message in context: http://vtk.1045678.n5.nabble.com/setSlice-problem-on-QVTKWidget-tp5715880p5715909.html Sent from the VTK - Users mailing list archive at Nabble.com.