def update_columns_dict(self, kwargs):
        """
        TODO: add documentation
        """
        super(Mesh, self).update_columns_dict(kwargs)

        # if kwargs.get('vnormals', None) is not None or kwargs.get('tnormals', None) is not None:
            # self._compute_mus()
        if kwargs.get('triangles', None) is not None:
            # reset visibilities and velocities so that they are reset
            # when next queried
            self.update_columns(visibilities=None, velocities=None)