All you need to know to get �started with GreenSock and �ScrollMagic, in one single package. Straight into your inbox. 2. Trigger Animation In The Middle Of The Viewport By default all animations (tweens and timelines) are triggered by ScrollMagic when the top of the triggerElement reaches the middle of the viewport. // Controller var controller = new ScrollMagic(); // 2. Curtain Timeline var tlCu