def METHOD_NAME(self, clear: bool=True) -> None:
    if self.import_vtk is False:
        return
    # remove
    item = self.vlayer.itemAt(0)
    self.vlayer.removeItem(item)
    if item is not None and item.widget():
        item.widget().deleteLater()
    # add
    self.renderer = vtk.vtkRenderer()
    self.interactor = QVTKRenderWindowInteractor(self)
    self.interactor.GetRenderWindow().AddRenderer(self.renderer)
    self.vlayer.addWidget(self.interactor)
    if clear:
        # set background
        self.renderer.SetBackground(vtk.vtkNamedColors().GetColor3d(
            "black"))
        self.interactor.Start()