def kdtree(self):
        """
        Return a scipy.spatial.cKDTree of the vertices of the mesh.
        Not cached as this lead to observed memory issues and segfaults.

        Returns
        ---------
        tree : scipy.spatial.cKDTree
          Contains mesh.vertices
        """

        from scipy.spatial import cKDTree as KDTree
        tree = KDTree(self.vertices.view(np.ndarray))
        return tree