Nested Animation
So, why is a movie clip called a movie clip? Well, it’s called that because it has the potential to be a nested animation inside your main animation (a movie inside the main movie). This makes it similar to a pre-comp in After Effects.
A simple scenario where you might want to use nested animation is a bouncing ball that travels from left to right as it bounces. A smart way to compose such an animation is to first animate a ball bouncing up and down in place. Then you animate the up-and-down-bounce moving left to right. In other words, the main animation (the top level) is an item moving left to right. But that item happens to be a ball bouncing up and down.
To return to a silly analogy from earlier, imagine Wonder Woman jumping up and down inside her invisible plane. The plane is the main animation and is moving across the sky. The item it’s moving is a nested animation—not just Wonder Woman but an animation of Wonder Woman jumping up and down.
Importing Layers from Photoshop
Let’s explore embedded animation by animating a satellite flying over the map. The satellite will have a spinning propeller top. In that sense it’s similar to the previous bouncing ball example. The spinning animation will be nested inside the flying animation.
To start, you’ll import more artwork from Photoshop.
- Continue working in the same file or open more_text_added.fla from the Chapter_02 Project Files folder. Choose File > Import > Import to Library and select satellite.psd from the Chapter_02 Project Files folder. Click Import to Library
- In the Import to Library dialog, select all the layers, and then select the “Create movie clips for these layers” option.
- Under Publish Settings, choose Lossless from the Compression drop-down list. Click OK.
Creating a Rotating-Propeller Symbol
Double-click the satellite.psd Assets folder and locate the layers from the Photoshop file in the Library. In the following steps, make sure you use the movie clip versions, not the source images.
- At the bottom of the Library, click the New Symbol button.
- Name the symbol Rotating Propeller, make sure the Type is Movie Clip, and then click OK. Flash takes you to symbol editing mode.
- Drag the movie clip symbol called propeller from the Library into the middle of the Stage, using the crosshairs as a guide.
- Right-click the propeller instance onstage and choose Create Motion Tween.
- Click anywhere inside the tween’s span.
- In the Properties panel, click the disclosure triangle to open Rotation and set the Rotate value to 1 time(s).
- Press Return (Enter) to watch the propeller spin one time around.
You just animated a propeller rotating but not on the main Timeline! That Timeline has a map of the world on it, and you don’t see that map here.
Your rotation animation is inside a movie clip’s Timeline. Movie clips are called movie clips because they have their own timelines that are independent of the main Timeline—just like pre-comps in After Effects have their own timelines that are separate from the Timeline of your final render composition.
Nesting a Symbol Inside Another Symbol
Now we’ll create a new symbol to house all the parts of the satellite. We’ll nest the rotating propeller inside it. First we’ll build the satellite.
- Continue working in the same file or open propeller_rotated.fla from the Chapter_02 Project Files folder. In the Library, click the New Symbol button. Name this symbol Animated Satellite, make it a movie clip, and click OK.
- On the satellite’s Timeline, create three layers and name them body, propeller, and antenna.
- Select the body layer and drag the body movie clip from the Library to the Stage.
- Select the propeller layer and drag the Rotating Propeller movie clip from the Library to the Stage. Don’t drag in the stationary propeller.
- Select the antenna layer and drag the antenna movie clip from the Library to the Stage.
- Drag the propeller so it’s sitting on top of the body.
Whenever you create a new symbol and click the OK button, think about how you’re being taken inside that symbol and how any animation that you do will be on its internal Timeline.
Skewing the Propeller in 3D
The propeller is now in the right position but not at the right angle. Fortunately, Flash CS4 has 3D manipulation tools that allow you to correctly adjust the propeller’s angle.
- Continue working in the same file or open satellite_parts_in_place.fla from the Chapter_02 Project Files folder. Double-click the icon next to Animated Satellite in the Library to open up the movie clip in symbol editing mode. Select the propeller onstage, and then switch to the 3D Rotation tool.
- In the Properties panel, click on the disclosure triangle beside 3D Position and View. Set the Perspective Angle, identified by a camera icon, to 1.0.
- Rotate and reposition the propeller until it matches the following illustration. You can nudge the propeller with the arrow keys on your keyboard. See the sidebar "Using the 3D Rotation Tool" for help.
- Switch back to the Selection tool, and drag the antenna into place on top of the propeller.
The Perspective Angle is similar to a camera angle. Setting it to 1.0 will make your manipulations easier.
If you switch back and forth between the 3D Rotation tool and the Selection tool (black arrow), you should be able to maneuver the propeller into place at the correct angle.
At this point, you’re currently working inside a symbol called Animated Satellite. Inside that symbol, you’ve embedded another symbol called Rotating Propeller.
Rotating Propeller is 30 frames long, but it’s embedded inside another symbol (Animated Satellite) that is only 1 frame long. This Alice in Wonderland situation is possible because each symbol’s Timeline is independent.
The Rotating Propeller and the static “movie” of the satellite body and antenna will play at the same time, fooling the viewer into thinking that the satellite has a rotating propeller on it.
If you press Return (Enter) now, you won’t see any animation because the only animation inside Animated Satellite is the propeller, and that is nested inside another movie clip (Rotating Propeller). When you press Return (Enter), you only see top-level animation. At the end of this exercise we’ll show you a way to preview nested animation, too.
Animating the Satellite on the Main Timeline.
Now that we’ve put our satellite together, it’s finally time to make it fly over the world.
- Continue working in the same file or open propeller_skew_done.fla from the Chapter_02 Project Files folder. Click the Back button to return to the main Timeline (the world map).
- Add a layer and name it satellite. Drag the layer to the top of the stack if necessary.
- With the satellite layer selected, drag an instance of the Animated Satellite movie clip from the Library to the Stage.
- Right-click the instance and select Create Motion Tween.
- Animate the satellite so that it arcs over the world (starting offstage and ending offstage). Make the animation’s span last for at least 200 frames. Remember, you can extend a tween further in time after animating it. The keyframes will move to new positions, keeping relative distances from each other intact.
- Extend the other layers. You can extend many layers at once by clicking the frame you want to extend to in the top layer and then Shift clicking the same frame in the bottom layer. Then Control-click (right-click) any frame in the selected range and choose Insert Frame from the context menu.
- Press Return (Enter) to view the animation.
- Press Command+Return (Ctrl+Enter) to see a preview of the final animation.
In Flash, the main Timeline is also called Scene 1.
You’ll see the satellite move, but you won’t see its propeller spin. Again, this is because pressing Return (Enter) only shows you top-level animations. The spinning propeller is nested, so you can’t see it this way.
Now you’ll see everything—the top-level animation and any nested animations. In Flash, Command+Return (Ctrl+Enter) is the shortcut for Control > Test Movie. Since it gives us a more accurate view of the final result than just pressing Return (Enter), we tend to use it most of the time to preview movies. Test to make sure movies open in their own window. When you’re done watching them, you can close them and return to working in Flash.
You probably noticed some looping. The Rotating Propeller looped and the main Timeline (Scene 1) looped. In Flash, all movie clips (and Scene 1) loop by default. This is very useful when you want to create bouncing balls and propellers. You only have to animate one bounce or one spin—the looping will happen automatically. If you don’t want your main Timeline to loop, you can stop it from doing so when you publish your movie (see “Publishing” next in this chapter).