See Ulrich, pp. 346-48.
Lev Manovich includes modularity among the distinguishing features of new-media products: "The objects themselves can be combined into even larger objects... without losing their independence" (Language of New Media, p. 30). Flash embodies this principle in the form of Movie Clips, special Symbols that have their own timelines and scriptable behaviors.
At first Movie Clips may seem to add more complexity than you really want; but as you take on more sophisticated design approaches, you'll find them indispensable.
This document steps through the process of constructing a simple Movie Clip animation: the pulsating golden circle that appears on the left side of the movie at the top of this page. There are of course other ways to build Movie Clips, but this example should show you the very basics.
Step 1: Create a Graphic Primitive
This simple circle, drawn with the Ellipse tool and entered into the Library as a Graphic, provides the basic content of the animation.
Step 2: Animate the Graphic in a Movie Clip
First we create a new Symbol called expandingCircle. We drag the circle graphic into the first keyframe and create a second keyframe at frame 20. In this end keyframe we scale the circle to 1000% and reduce its alpha to about 25%. After adding Motion Tweening, we can see the circle expand and fade away, a bit like a smoke ring.
Step 3: Multiply the Single Animation in a Compound Movie Clip
Here we create yet another Movie Clip Symbol, this time called circlePulser. This clip contains five layers, each of which holds one keyframe followed by 18 regular frames. Each keyframe contains an instance of the expandingCircle Movie Clip. The 19-frame spans begin 10 frames further down the timeline in each layer. The result is what you see above: a pulsating sequence of five expanding, fading circles.
Small detail: why use 19 frames when the original expandingCircle animation consists of 20 frames? We do this because we need an interval of blankness at the end of each expansion cycle.
The best way to understand this example is to look at the source file and its timelines. You'll find the source for the multi-element animation at the top of the page in MMShare/movieClips/mcDemo.fla on Crow. The source for the simpler, expanding-circle example is in MMShare/movieClips/circlePulser.fla.
