Flash利用材质和遮照创建真实的小球动画

Flash利用材质和遮照创建真实的小球动画(2) yspeed = 0;
xspeed = 0;
friction = 0.95;
_root.attachMovie("ball", "ball", 1, {_x:250, _y:175});
ball.texture.setMask(ball.ball_itself);
ball.onEnterFrame = function() {
    if (Key.isDown(Key.LEFT)) {
        xspeed -= power;
    }
    if (Key.isDown(Key.RIGHT)) {
        xspeed += power;
    }
    if (Key.isDown(Key.UP)) {
        yspeed -= power
    }
    if (Key.isDown(Key.DOWN)) {
        yspeed += power
    }
    xspeed *= friction;
    this._y += yspeed;
    this._x += xspeed;
};

　　效果如下：

　　然后我们让该球真的滚动起来，滚动的更加真实。

power = 0.3;