code: def points(self, points):
          
          if not isinstance(points, np.ndarray):
              raise TypeError('Points must be a numpy array')
          # get the unique coordinates along each axial direction
          x = np.unique(points[:,0])
          y = np.unique(points[:,1])
          z = np.unique(points[:,2])
          # Set the vtk coordinates
          self._from_arrays(x, y, z)
          #self._point_ref = points
          self.Modified()
docs: set points without copying