let() does "Sequential assignment of variables inside an expression." // args should be in clockwise order looking from the outside function normal(p1, p2, p3) = let(u = p2 - p1, v = p3 - p1, x = u[1]*v[2] - u[2]*v[1], y = u[2]*v[0] - u[0]*v[2], z = u[0]*v[1] - u[1]*v[0]) [x, y, z]; -- View this message in context: http://forum.openscad.org/function-syntax-tp5915p18821.html Sent from the OpenSCAD mailing list archive at Nabble.com.