Chapter 9
Layers are important for many reasons, but mainly because they allow you to separate static from dynamic content.
There is an internal stacking order for multiple elements within a layer. You probably won't encounter this feature very often, as one usually places elements on separate layers if they will overlap at some point.
Layers (in themselves) do not add to file size; though of course, their contents certainly do.
When adding a new layer, begin by clicking on the layer which you want to end up below the new one.
New layers automatically have the same number of frames as the longest layer in the timeline.
In Outline Mode, the contents of a layer are represented as outlines. This can be useful if you are trying to cut through visual clutter in order to align an animation.
Guide Layers can be used to remove content selectively and temporarily from a movie being exported for test purposes. Simply change the layer you wish to suppress into a Guide Layer.
Mask Layers are enormously interesting and powerful. They can be used to create an aperture through which content on a different layer (not necessarily just the one below) can appear.
You can link multiple layers to a Mask Layer: see Fig. 9.21 on p. 229.
Motion Guide layers are used to control non-linear or curvilinear animation.
Chapter 10
Frame rates: faster is not always better. Remember that Flash is always processor-dependent. If you design a movie to use the full potential of a very fast machine, it will drop frames and otherwise degrade when viewed on a lesser computer. A rate of 12 frames per second is a good, solid choice, and you probably shouldn't exceed 24 fps in most instances. Traditional movies are projected at 24 fps, some video at about 30 fps. You might want to limit yourself to 20 fps for general-purpose Web consumption, owing to slow streaming times.
Video formats (QuickTime, AVI) provide ways to use higher frame rates effectively.
The Synchronize Symbols feature fits oddly looped symbols (movie clips with their own timelines) into the timing of a particular scene, even if there is an inexact correspondence between former and latter.
Ever wonder what those blank white frame-like things are? They are placeholder frames, which are not real frames at all.
Shape Tweening vs. Motion Tweening. You can shape-tween only simple shapes. Motion tweening, on the other hand, is restricted to symbols.
To facilitate shape tweening, you may add up to 26 Shape Hints. Why 26? Because that's how many letters there are in the alphabet. An interesting design decision...
Using QuickTime content in Flash movies: You can do this, but you should know that you are heading into poorly charted waters. The Flash 5 player (plug-in) does not support QuickTime. The QuickTime plug-in does support Flash, but only Flash 3, which means that most ActionScript commands, such as getURL() and loadMovie(), won't work. You can add Flash animations over a QuickTime movie or add buttons to control the video playback.
Franklin and Patton observe that the QuickTime video will not appear in the test version of your Flash movie; this is true, but the QuickTime movie will appear, frame by frame, on the stage in the authoring environment. In fact, the QuickTime movie's frames are usefully distributed in a one-to-one relationship with Flash frames (meaning it's a good idea to set your Flash and QuickTime movies to the same frame rate).
As with sound clips, you will need to add frames to your Flash timeline after you have dragged a QuickTime movie onto the first keyframe of a layer. Scrub the playback head over the QuickTime frames until you see a big blue "X" on the stage. This indicates the end of your QuickTime clip.
Hybrid Flash/QuickTime movies must be saved as QuickTime (and thus can be played only if the user has Apple's QuickTime plug-in). In my experience, it is also necessary to add a play() command as frame action for the first keyframe of a hybrid movie, to ensure that it begins to stream. You may not see this problem on all servers or in all circumstances. (I've had the problem on Raven, which runs one type of server software, but not on Crow, which runs something else.)
Sometimes you may want to use HTML effects on the page that contains a hybrid Flash/QuickTime movie: for instance, the automatic refresh function using the <META> tag. I've discovered that the QuickTime plug-in will not return control to the browser if the hybrid movie ends on a Flash keyframe, instead of the final frame of the QuickTime movie. As a general practice, try to end hybrid movies on a QuickTime frame.
