Animation and Effects with Macromedia Flash MX 1002004 [Electronic resources] نسخه متنی

Understanding Tweens

There are four kinds of animation you can do in Flash: motion tweens, shape tweens, frame-by-frame animation, and scripted animation. Only two of those forms of animation are tweens. A tween is the motion that you create between a beginning and an end state. It refers to the "in-between" frames on the Timeline that create the appearance of motion. Essentially, "tween" is short for "in-between".

Chapter 3.

Chapters 4 and 7, respectively.

For examples of each form of animation, see www.FLAnimation.com/chapters/02/ani_examples.

Often, you can use different forms of tweening or animation to accomplish similar results. Despite the fact you usually have a few ways to attain the same results, some forms of animation are better than others for specific tasks.

If you animate an object across the Stage, you could use any form of animation: motion tween, shape tween, frame-by-frame, or scripted animation. If you want to animate along a curved or irregular path, motion tweens are typically the best and easiest solution. All you need to do is draw a path, as shown in this chapter's project, and attach the object to that path.

Other forms of animation should be used depending on the situation. Motion tweens create motion, and shape tweens should be used for morphing objects into other shapes. You should use frame-by-frame animation for complex effects or fine-tuning. Scripted animation should be used when you need to reuse animations, create animation that depends on something happening (such as an image loading into the SWF file), or very simple or repetitive tasks.

Using motion tweens

You use motion tweens to move, rotate, modify size, and modify alpha levels of an object on the Stage. You can also use motion tweens to force an object to follow a path you create (which can be useful when you want to make a car drive around a track or a bird fly in a specific path, for example). Motion tweens let you accomplish these kinds of animations without creating a series of complex drawings or adding many tweens to a project. You make changes to a selected instance on the Stage using keyframes, and then add the motion tween to the Timeline.

Chapter 1, symbols are assets in a file that are reused, so they help you reduce file size and improve performance.) You can also group drawings you make on the Stage by choosing the object and then selecting Modify > Group. Group raw data to make them easier to select and use in an FLA file. The objects you group must be on the same layer, or if you create a symbol the objects merge onto the same layer.

When you separate tweened instances onto their own layers, you might end up with a large number of layers on the Timeline. To help organize the layers, use layer folders. Click the Insert Layer Folder button on the Timeline to create a new folder and then drag all the similar layers on the Timeline into that folder. This procedure lets you expand and collapse folders in the Timeline, which keeps the Timeline more organized and manageable. Using layer folders does not affect the appearance of layers on the Stage.

You add motion tweens in several different ways. Select the key frame you want to add the motion tween to, and then do one of the following:

Select Insert > Timeline > Create Motion Tween.

Right-click (Windows) or Control-click (Mac) and select Create Motion Tween from the context menu.

Choose Motion from the Tween pop-up menu in the Property inspector.

It is important to understand that you can have only one motion tweened instance existing on a single layer on the Timeline, and no other graphics should be on that layer. If you attempt to tween multiple instances on the same layer, you encounter unexpected, and unwanted, results. Essentially, your animation won't animate properly, such as motion tweening in the wrong direction and so on.