As an After Effects user, you’re probably familiar with “easing”—the animator’s term for changing velocity over time (accelerating and decelerating). If you’re like us, you rarely consider an animation complete until you’ve added easing. So you’ll be tickled pink to discover that Flash has two easing tools: one that is quick and simple; another that is complex and feature-rich. Let’s look at the simple tool first.
- Animate the rest of the vehicles (the ones not yet animated), using whichever tweening method you want and making sure all layers extend to the same length. Or you can open all_vehicles_tweened.fla from the Chapter_02 Project Files folder. Play the animation, watching one of the planes flying from point A to point B. Notice that it doesn’t accelerate (ease in) or decelerate (ease out).
- Click any frame within the tween’s span.
- In the Properties panel, scrub the Ease value (zero by default) to the left as far as it will go (-100).
- Replay the animation, noting that the plane now accelerates. Scrub the Ease value to the right as far as it will go (100). Then replay the animation, noting that the plane now decelerates.
Just easing in is great for objects that start onstage and leave (ending in the gray area offstage); easing out is perfect for objects that start offstage and end onstage.
But a plane that moves between two points onstage should ease in at the start of its journey and ease out at the end. There’s no easy way to achieve this with the simple Ease value in the Properties panel, since it forces you to choose between accelerating and decelerating.