        self.iren = self.ui.vtkWidget.GetRenderWindow().GetInteractor()

        # Create source
        source = vtkSphereSource()
        source.SetCenter(0, 0, 0)
        source.SetRadius(5.0)
--
        self.iren = self.vtkWidget.GetRenderWindow().GetInteractor()

        # Create source
        source = vtkSphereSource()
        source.SetCenter(0, 0, 0)
        source.SetRadius(5.0)
