Returns a new point representing this latitude and longitude under
    a spherical Earth model.

def FromLatLng(lat, lng):
    """
    Returns a new point representing this latitude and longitude under
    a spherical Earth model.
    """
    phi = lat * (math.pi / 180.0)
    theta = lng * (math.pi / 180.0)
    cosphi = math.cos(phi)
    return Point(math.cos(theta) * cosphi,
                 math.sin(theta) * cosphi,
                 math.sin(phi))