In your loop where you apply the sine, add a before/after print, like so:
before = gPlane_p2_y for degree in range(361): y_value = math.sin(pi / 180 * degree) gPlane_p2_y += y_value print("{0} => {1}".format(before, gPlane_p2_y))You'll quickly see that gPlane_p2_y (the only value you change) is pretty much always 360, which explains why you don't see any movement... because none of the numbers are changing.