25 July 2010
Easing is a technique for modifying the way that Adobe Flash Professional calculates the property values in between property keyframes in a tween. Without easing set, Flash moves tweened objects at the same speed on each frame of the animation. With easing, you can adjust the speed of tweened objects to make movements appear more natural and to create complex animations.
An ease is a mathematical curve that is applied to the property values of a tween. The final effect of the tween is the result of the combination of the range of property values in the tween and the ease curve that makes the tweened objects start slow and speed up, start fast and slow down, or some combination of these effects.
For example, if you animate a picture of a car across the Stage, the motion is more realistic if the car starts slowly from a stopped position and gradually gains speed as the acceleration builds momentum.
Eases applied in the Property inspector affect all of the properties that are included in a tween. Eases applied in the Motion Editor can affect a single property, a group of properties, or all of the properties of a tween.
An ease can be simple or complex. Flash includes a range of preset eases that you can apply for simple or complex effects. In the Motion Editor, you can also create your own custom ease curves by using the Bézier handles to edit curve segments.
To learn more, see Ease individual properties in the Motion Editor in the Flash documentation.