returns a pointer to the points as a numpy object

def points(self):
        """ returns a pointer to the points as a numpy object """
        x = vtk_to_numpy(self.GetXCoordinates())
        y = vtk_to_numpy(self.GetYCoordinates())
        z = vtk_to_numpy(self.GetZCoordinates())
        xx, yy, zz = np.meshgrid(x,y,z, indexing='ij')
        return np.c_[xx.ravel(), yy.ravel(), zz.ravel()]