Recipe 3.6. Lengthening the Duration of the Movie

Problem

You want to extend the duration of a movie.

Solution

Insert frames.

Discussion

When you open a new Flash document, it contains only one frame (possible exceptions being documents based on some templates). With only one frame, the Flash document has no provision for time. To enable elements to change over time, you should add multiple frames.

An important exception to the concept of animations requiring multiple frames is ActionScript-based movies. Many Flash applications exist entirely on a single frame, with all interactivity and animation controlled at runtime with ActionScript.

Using the default frame rate of 12 fps, a single-frame movie lasts one-twelfth of a second. To lengthen a movie, to make room for changes of content, you add new frames. Figure 3-1 shows the main timeline of a movie with 12 frames. Though frame placeholders exist for frames 13 and higher, these frames do not actually exist.

Figure 3-1. At 12 frames, this movie would last one second

In addition to frames, Flash's timeline also contains the playhead (shown in Figure 3-1). The playhead indicates the active frame. The stage displays all the contents for the frame that contains the playhead. In other words, to modify portions of a movie that occur earlier or later than the contents currently showing on the stage, drag the playhead until it is in the frame that contains the elements you want to modify.

You can add frames to a movie one at a time or in groups by using the Insert Frame command or by pressing F5, its keyboard shortcut. The result of this action depends on a number of factors, but in all cases, new frames are always added after the selected or active frame (that is, the frame containing the playhead).

• To insert a single frame in only one layer, select a single frame in one layer, and choose Insert Frame.

• To insert a single frame in all layers, position the playhead in the frame after which you want to add the new frame, and choose Insert Frame.

Flash also makes it possible to add multiple frames at once. For example, if you know that your animation should be 10 seconds, and your movie's frame rate is 12 frames per second, you need to add 119 frames after the original frame. You can insert all these frames at once. You can also duplicate frame spans, one after the other.

• To insert multiple new frames, select the frame placeholder where you want the frames to end and choose Insert Frame. Doing so inserts a new frame in the selected frame placeholder as well as in all the intervening frames between the selected frame placeholder and the original last frame in that layer.

• To duplicate a selected span of frames, select the desired frames, which can include multiple contiguous frames in multiple contiguous layers, and choose Insert Frame.

You can add frames to the middle of a movie, and not just to the end. For example, if you have an animation that lasts 20 frames, and it goes by too quickly, you can lengthen the animation by adding several frames in the middle of the animation. To do so, position the playhead to the frame after which you want the new frames to appear, and select Insert Frame or press F5. To add a half-second to an animation, insert 6 frames, if the frame rate is 12 frames per second.

See Also

Recipe 3.7, Recipe 3.8