26 July 2010
Shape tweening in Adobe Flash Professional involves drawing a vector shape on one specific keyframe in the Timeline and then creating another keyframe and drawing another shape on the second keyframe. When you right-click or Control-click any of the frames between the two keyframes and choose Shape Tween in the menu that appears, Flash interpolates the intermediate shapes for the frames in between, creating an animation of the first shape morphing into the second shape.
Shape tweens work best with simple vector shapes. Avoid using shapes with cutouts or negative spaces. Also avoid complex shapes because they tend to turn inside out.
Note: You can use shape hints to specify which points on the beginning shape should correspond to specific points on the ending shape.
You can also tween the position, color, and transparency of shapes in a shape tween:
To apply shape tweening to groups, instances, or bitmap images, break these elements apart by choosing Modify > Break Apart. To apply shape tweening to text, choose Modify > Break Apart twice to convert the text to individual character objects.