code: def probePlane(img, origin=(0, 0, 0), normal=(1, 0, 0)):
      
      plane = vtk.vtkPlane()
      plane.SetOrigin(origin)
      plane.SetNormal(normal)
  
      planeCut = vtk.vtkCutter()
      planeCut.SetInputData(img)
      planeCut.SetCutFunction(plane)
      planeCut.Update()
      cutActor = Actor(planeCut.GetOutput(), c=None)  # ScalarVisibilityOn
      cutActor.mapper.SetScalarRange(img.GetPointData().GetScalars().GetRange())
      return cutActor
docs: Takes a ``vtkImageData`` and probes its scalars on a plane.
  
      .. hint:: |probePlane| |probePlane.py|_