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Animating with Shape
Tweening
Introduction
Shape tweening works similarly to motion tweening. It fol-
lows the same structure of keyframing in the Timeline. You
can animate many of the same changes such as alpha, color,
scale, and position, though its main purpose is to transform
the shape of an object into another shape. Whereas motion
tweening is applied to groups and symbols, shape tweening
must be applied to an editable shape. You can determine
whether an object is editable by selecting it with the
Selection tool—if it doesn't have a bounding box when
selected, shape tweening can be applied. The reason for this
is that when you convert a shape into a symbol, you are
essentially protecting it from editing by storing it in its own
Timeline. To apply shape tweening to a symbol, you must
enter symbol editing mode and apply it to the shape con-
tained inside the symbol. Shapes are created with any of
Flash's drawing tools, such as the Oval or Rectangle tools. By
making changes to the shape with any of Flash's editing
tools, you can change the contours of the shape (for exam-
ple, turn a circle into a square) and then use shape tweening
to make this change happen gradually over time. Because the
results of a shape tween can be unpredictable, you can set
shape hints to let Flash know how to proceed with the tween.
This is useful when you are working with complex shapes
such as letterforms. In all cases you should only tween one
shape at a time in a tweened span for best results.
In addition to shape tweening, you can also animate
shapes using Inverse Kinematics (IK), which allows you to

to alter the form of any editable shape gradu-
ally. Place artwork in a keyframe and then use
any of Flash's drawing and editing tools to
adjust the contours of a shape on another
keyframe. When you apply shape tweening,
Flash draws the frames in-between the two
keyframes so that the object appears to
"morph" between the two states. To provide
even more control, you can use shape hints.
Using Shape Tweening
Shapes created with
the Polystar tool
Break apart letterforms
for shape tweening
Using the Polystar Tool
Using Shape Hints
From the Library of Wow! eBook
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Chapter 10 Animating with Shape Tweening
275
For best results, tween shapes separately on different layers.
Creating Complex Animations
From the Library of Wow! eBook
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276
Chapter 10
In most cases, you can easily shape tween any two simple shapes.
Geometric forms such as lines, rectangles and circles yield the best
results. Because Flash draws the tweened frames mathematically, the
simpler the shape, the more likely it will tween without any problems or

Chapter 10 Animating with Shape Tweening
277
Select frame 10.
Click the Insert menu, point to
Timeline, and then click Blank
Keyframe.
Flash tints a shape-tweened span
a pale green.
TIMESAVER
Press F7 to add a
blank keyframe.
With any of Flash's drawing tools,
draw a different shape on the
Stage at frame 10.
Click the Control menu, point to
Test Movie, and then click Test.
The shape on frame 1 slowly
transforms into the shape on
frame 10.
TIMESAVER
Press
A
+Return
(Mac) or Ctrl+Enter (Win) to test it.
8
7
6
5
Beginning Shape
on Frame 1