def make_xz_ground_plane(vertices):
    """
    Given a vertex mesh, translates the mesh such that the lowest coordinate of the mesh
    lies on the x-z plane.
    :param vertices: (N, 6890, 3)
    :return:
    """
    lowest_y = vertices[:, :, 1].min(axis=-1, keepdims=True)
    vertices[:, :, 1] = vertices[:, :, 1] - lowest_y
    return vertices