How to use Shape Tween in Flash
Tutorial adapted from Flashtutor.org, and Adobe.com Flash Help files.
Shape tween is an animation that involves transformation of one shape to another. You’ll learn how to create the flash animation below. In shape tweening, you draw a vector shape at one specific frame in the Timeline, and change that shape or draw another shape at another specific frame. Flash Professional then interpolates the intermediate shapes for the frames in between, creating the animation of one shape morphing into another.
Firstly, draw a circle using the Oval tool. Now we’ll try converting the frame to a shape tween.
Let’s click on the 1st frame.
Select frame 10 of the same layer and add a blank keyframe by choosing Insert > Timeline > Blank Keyframe or pressing F7.
Now you are supposed to draw the rectangle. But, you probably can’t place the rectangle in perfect alignment with the circle, because you can’t see it. A nice feature called “Onion Skin” in Flash can help you view frames before or after a selected frame. You can use Onion Skin to align your rectangle with the circle.
Make sure the last frame is selected. Then, click on the onion skin icon. You can’t see the circle’s “shadow” yet, this is because the onion skin did not affect the frame where the circle is placed in.
So, we’ll drag the onion skin box located above the frames to encompass all frames.
The circle’s semi transparent shadow should now show on the stage of the last frame.
Now you can draw a rectangle on the stage, it should be positioned close to the circle.
Right-Click on Frame one and choose “Create Shape Tween”. Preview your movie.
The shape tween is done!
Here is a very fast tutorial and explanation of Shape Tweening by Alan Becker: