Idea is from page 37 of the art_of_maya.pdf online book. Bounce Expression ball.translateX = time * 5; ball.translateY = 6 * abs(sin(time*3)); ball.rotateZ = -(time*81); ball.scaleX = 1 + time / 2; ball.scaleY = 1 + time / 2; ball.scaleZ = 1 + time / 2;