    reader = vtkSTLReader()
    reader.SetFileName(mesh_filename)
    reader.Update()
    mesh = reader.GetOutput()
    bounds = mesh.GetBounds()

--
    reader = vtkSTLReader()
    reader.SetFileName(filename)

    mapper = vtkPolyDataMapper()
    mapper.SetInputConnection(reader.GetOutputPort())

--
    reader = vtkSTLReader()
    reader.SetFileName(filename)

    mapper = vtkPolyDataMapper()
    mapper.SetInputConnection(reader.GetOutputPort())

--
        reader = vtkSTLReader()
        reader.SetFileName(file_name)
        reader.Update()
        poly_data = reader.GetOutput()
    elif extension == '.vtk':
        reader = vtkpoly_dataReader()
--
        reader = vtkSTLReader()
        reader.SetFileName(file_name)
        reader.Update()
        poly_data = reader.GetOutput()
    elif extension == '.vtk':
        reader = vtkPolyDataReader()
--
    stl_reader = vtkSTLReader()
    stl_reader.SetFileName(probe_fn)
    stl_reader.Update()

    surface = stl_reader.GetOutput()
    bounds = np.array(surface.GetBounds())
--
        reader = vtkSTLReader()
        reader.SetFileName(file_name)
        reader.Update()
        poly_data = reader.GetOutput()
    elif extension == ".vtk":
        reader = vtkPolyDataReader()
--
        reader = vtkSTLReader()
        reader.SetFileName(file_name)
        reader.Update()
        poly_data = reader.GetOutput()
    elif extension == '.vtk':
        reader = vtkPolyDataReader()
--
        reader = vtkSTLReader()
        reader.SetFileName(file_name)
        reader.Update()
        poly_data = reader.GetOutput()
    elif extension == '.vtk':
        reader = vtkPolyDataReader()
--
        reader = vtkSTLReader()
        reader.SetFileName(file_name)
        reader.Update()
        poly_data = reader.GetOutput()
    elif extension == '.vtk':
        reader = vtkPolyDataReader()
--
            reader = vtkSTLReader()
            reader.SetFileName(file_name)
            reader.Update()
            poly_data.DeepCopy(reader.GetOutput())
        elif ext == '.vtk':
            reader = vtkPolyDataReader()
--
        reader = vtkSTLReader()
        reader.SetFileName(file_name)
        reader.Update()
        poly_data = reader.GetOutput()
    elif extension == '.vtk':
        reader = vtkXMLPolyDataReader()
--
        reader = vtkSTLReader()
        reader.SetFileName(file_name)
        reader.Update()
        poly_data = reader.GetOutput()
    elif extension == '.vtk':
        reader = vtkpoly_dataReader()
--
        reader = vtkSTLReader()
        reader.SetFileName(file_name)
        reader.Update()
        poly_data = reader.GetOutput()
    elif extension == '.vtk':
        reader = vtkpoly_dataReader()
--
        reader = vtkSTLReader()
        reader.SetFileName(file_name)
        reader.Update()
        poly_data = reader.GetOutput()
    elif extension == '.vtk':
        reader = vtkpoly_dataReader()
--
        reader = vtkSTLReader()
        reader.SetFileName(file_name)
        reader.Update()
        poly_data = reader.GetOutput()
    elif extension == ".vtk":
        reader = vtkXMLPolyDataReader()
