Easing refers to the gradual acceleration or deceleration during an animation, which helps your tweens appear more realistic or natural. Use easing to apply a special movement that makes animation tasks, such as "random" movement or a ball bouncing. You can apply eases to add a more natural appearance of acceleration or deceleration by gradually adjusting the rate of change using a gentle ease curve. You can add eases to create a random appearance to one of your properties, such as x and y for random jittery movement.

Animate provides two methods to apply easing to a motion tween.

• You can specify an easing value for each motion tween using the Ease slider in the Motion Property inspector.
• You can use the Motion Editor to apply either a preset or custom ease to one or more properties.

Applying easing to a motion tween using the Motion Property inspector:

1. Create a file named motionease.fla.
2. Create a graphic with any of the drawing tools, select all the graphics, and then right/Control-click and choose Create Motion Tween. Click OK to convert the drawing into a symbol. One second of frames are added to the timeline, but if necessary, drag the end of the tween span so it's at least 24 frames long.
3. Move the playhead to the last frame of the tween span, and then move the instance to another location on the Stage.
4. Select the tween span and drag the Ease hot text (blue text next to "Ease") in the Motion Property inspector. You can also type in a value to adjust the rate of change between tweened frames.
5. To begin the motion tween, and accelerate the tween toward the end of the animation:
   • Drag the hot text to enter a negative value from –1 through –100.
   • Drag the hot text to enter a positive value from 1 through 100.
6. Select Control > Test Movie to test the animation. Notice how the tween dots update on the Stage in the authoring environment after you apply the ease.

5. Scroll down to the Ease section, and change the number of bounces to 5.

See also

Eases in the Motion Editor

After you apply any ease to a graphable property, any hot text in the Value category is dimmed. The easing equation controls the hot text (tweened values) and there are limitations to what that value can be. Instead, edit the solid curve in the graph using the control points or other Bezier editing tools. Alternatively, you can disable the ease and use the hot text controls, then re-enable the ease and see the outcome of your changes.

Adding a custom ease to a motion tween

Use custom easing to create your own ease using a graph in the Motion Editor. You can also apply the custom ease to any property of your tweened instance.

The Custom ease graph represents the degree of motion over time. Horizontal axis represents the frames and the vertical axis represents the tween's percentage of change. The first value in the animation is 0%, and the last keyframe can be set from 0 through 100%. The slope of the graph's curve shows the rate of change of the tweened instance. If you create a horizontal line (no slope) on the graph, the velocity is zero. If you create a vertical line on the graph, there is an instantaneous rate of change.

1. Create a motion tween.
2. Select the tween span in the Timeline and open the Motion Editor.
3. Scroll to the Eases category, click the Add button, and then select Custom from the menu.

    

Modifying and applying a custom ease

You can then edit the custom ease using the standard Bezier editing controls found in other property graphs in the Motion Editor. Use this feature to create a custom curve that you can use to ease between keyframes. 

To apply the custom ease to a property, select the custom ease's name from the Ease menu. The property graph updates with a dashed curve that displays the actual tweened values after the ease is applied.

Copying and saving custom eases

Use any of the following methods to reuse your custom eases on other tween instances, or even in other documents:

• Right-click the custom ease graph (outside the graph's curve) and choose Copy Curve. Then on the second instance, add a custom ease, and right-click in the custom ease graph and choose Paste Curve. You can paste the graph to any other non-spatial property graph.
• Save the custom ease in a Motion Preset.