he said "thus better use two passes".
separating the code in two is no deal- i just wanted to post it because i often read the request for an upside-down terrain. and, i learned sth. myself...
surely, in a game, iŽd use two terrains, one with cw and one ccw, as you suggested, because it is unprobable that iŽll have to move transitionlessly from outdoor to a cave area.