#42 Copying and Pasting Motion
It's always been possible to copy and paste animation from one part of the Timeline to another. One of the new features in Flash CS3 goes a step beyond that: It allows you to copy animation from one object and apply it to another.
Let's say, for example, that you're animating three different cars, each one starting from a different place on the Stage. You want each car to go straight, make a left, make a right, and roll over. In previous versions of Flash, there was no easy way to do this without using ActionScript, but in Flash CS3 it can be done in a few seconds:
- Create graphic symbols for all three cars and put each one in its proper place on the Stage.
- Motion-tween the first car.
- Select the first car on the Stage and choose Edit > Timeline > Copy Motion.
- Select the second car on the Stage and choose Edit > Timeline > Paste Motion.
- Repeat step 4 for the third car.
When you copy animation from one object and paste it to another, the motion is relative to the object, not to the Stage. As a result, each car can execute the same set of maneuvers in completely different locations.
There are a couple of potential problems that you'll need to be alert for. Imagine that the second and third cars are both in the same keyframe on the same layer. That's fine, so long as they're standing still. But as soon as you paste the first car's motion to the second car, you've turned the second car into a motion-tweened object; as you'll remember from #38, a motion-tweened object has to be on a layer of its own. So you'd have to move the second and third cars to separate layers before you could paste motion to them.
Similarly, suppose the first car's animation has a duration of 100 frames, but the second and third cars are in the movie for only 50 frames. When you paste the first car's motion to the second car, Flash will automatically lengthen the second car's span by 50 frames. If there's any action in the Timeline that's later in the same layer, that action will be delayed by 50 frames, possibly losing coordination with the action in the other layers (Figure 42a).
Figure 42a These two views of the Timeline show what happens when motion from Symbol 1 is pasted to Symbol 2.