code: def cellCenters(self):
          
          vcen = vtk.vtkCellCenters()
          vcen.SetInputData(self.polydata(True))
          vcen.Update()
          return vtk_to_numpy(vcen.GetOutput().GetPoints().GetData())
docs: Get the list of cell centers of the mesh surface.
  
          .. hint:: |delaunay2d| |delaunay2d.py|_