Flash CS3 shape tweening tutorial

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Overview

• Shape tweening means that you transform an object from one state into an other. This is usually called morphing
• This article is part of some other Flash tutorials.

Learning goals

Learn about basic Flash 9 (CS3) shape animation.

Prerequisites

Flash CS3 desktop tutorial

Flash layers tutorial

Flash drawing tutorial

Flash object transform tutorial

Flash frame-by-frame animation tutorial or Flash motion tweening tutorial

Moving on

The Flash article has a list of other tutorials.

Quality

This text should technical people get going and may not be good enough for self-learning beginners. It can be used as handout in a "hands-on" class. That is what Daniel K. Schneider made it for...

Level

It aims at beginners. More advanced features and tricks are not explained here.

Materials (*.fla file you can play with)

http://tecfa.unige.ch/guides/flash/ex/shape-tweening-intro/

The executive summary

Introductory example

The principle

You can transform any form into any other form.

Shape tweens work on so-called editable objects, e.g. it will not work with symbols or grouped objects. You may shape tween:

• Drawing objects (drawings made in object mode)
• Shapes (drawing made in merge mode)

Also, as in motion tweening, the object to be shaped must be in a separate layer.

Step 1 - Draw an object

• We draw an oval with a think border with the Oval tool and also set the background.
• Then we center the oval in the stage. To do so, use the Align panel (Window->Align, or hit Crtl-K)
  • Check to stage and click on the Align icons until you get it right :)

You should have something like this:

A starting frame with an Oval to be morphed

Step 2 - Insert a new blank keyframe

• Right-click on frame 10 and Insert Blank Keyframe or hit F7 (not "Insert Frame" / "Insert Keyframe" (F6))

This will insert an empty new Keyframe

Step 3 - Add a new object to the new keyframe

In this frame, draw a new object, i.e. we inserted a Polystar, also in object mode.

• Select the Polystar tool (It sits below the rectangle tool and you must hold down the mouse to get at it)
• Then, in the properties panel, select from the Options pull-down menu: Star and Number of sides = 9
• Then, draw it

Step 4 - Change its shape and align it with the oval and the stage

Then make it a bit "oval" and adjust it more or less to the size of the oval

• Either click on the Free Transform Tool or Right-click on the polystar; Select Free Transform
• Drag out one side
• To see the oval you can click on the "Edit multiple frames" icon in the Timeline control bar.
• Then make again sure that it is centered by using the Align panel

You should have something like this:

A polystar

Step 5 - Change colors of the polystar

• Untick the "Edit multiple frames" icon !!
• Then you can change the colors of the stroke and the fill

Step 6 - Morph

• Click on an empty frame between the two keyframes
• In the properties panel below select Tween: Shape
• Alternatively: Just right-click on an empty frame and select Create Shape Tween

Test

• Move around the playhead
• Menu Control->Test Movie

Done :)

You can admire the result

Morphing a picture - take one

You can not morph bitmaps (e.g. photographs). So have to find a way to turn faces into vector graphics.

Step1 - Trace the bitmap

Illustrator CS3 can trace bitmaps

• Open the picture in Illustrator
• Select it
• Now you will have a "Live Trace button" on the control panel on top
• Next to it is a little pulldown menu from which you can select various options, for a portrait you may choose "Color 16"

Live tracing with IllustratorCS3

Once you hit the trace button, the controls on top will change and you can play with all sorts tracing methods and parameters

Live tracing controls with IllustratorCS3

Step2 - Import to Flash

• Copy/paste if from Illustrator with the options: Paste using AI File Importer preferences and untick maintain layers
• You may adjust the size of the stage to the size of the picture somewhat, I chose to add some big margins for a reason you will see later.
• Convert it to a symbol (so that you have a copy in the library)

Step 3 - Break it Apart

• Then right-click->Break Apart
• You have to do this several times, since illustrator produced object groups within object groups (use ctrl-Z if you think you went too far).

Step 4 - Create a new keyframe

• Right-click on frame 20 and Insert Keyframe (this time we will not start with a blank keyframe, but copy over the picture from frame one)

Step 5 - Distort the picture in keyframe 1

Try everything you can

• Select parts and change the color with the paint bucket. That's actually the only thing I did
• You also can move parts, but probably you then should start with a much simple ray trace.
• Distort parts with the Selection Tool, the Subselection tool and the Free Transform tool

Step 6 - Add a shape tween between the two frames

... enjoy

Tune

• You also may at the very end (after the last keyframe) insert the original jpg picture. Tracing bitmaps is a very difficult issue, since there are many kinds of algorithms you can select from.

Basically the machine must be told how to group similar pixels together into a vector objects. This can be shades of light, proximity of similar pixels that look like lines, colors, etc.

Publish

• In the HTML setting you probably want to take off the "loop" option

You can admire the result (files flash-cs3-shape-picture-morphing.*)

Morphing a picture - take two

The free Inkscape editor can also trace

• File->New ; Select the bitmap file (e.g. a *.jpg)
• Select it (!)
• Path -> Trace Bitmap item (or Shift-Alt B)
• You then will see a popup with various options, Click on Update to make as many trials you like. Make sure your picture is selected. Then play with:
  • Brightness cutoff
  • Edge detection
  • Color quantisation
• Each of these does different sort of traces.
• Click on OK once you are happy
  • The original picture will still be there. Remove it and save the result with File->Save As

Using two graphics from start

This time I used another strategy:

• I made two different traces with Inkscape
• I used one for keyframe 1 and the other for keyframe 2 and save them in SVG
• Since Flash cannot import SVG (why the hell ?) I open these files in Illustrator and then pasted to Flash.

Changing the background color

• I added a new layer and painted a rectangle over the stage in Keyframe 1
• Same for a new keyframe
• Then a shape animation between the two.

You can admire the result (files flash-cs3-shape-picture-morphing2.*)

Ok that would be the only picture of me in edutech wiki, let's now move to more dangerous stuff ...

Morphing a simple shape

In this animation I made three keyframes

• Something like a tear in the first
• Tear decomposing at the bottom
• The bottom will decompose into the beginning of a monster

Ok it was done in 5 minutes ....

You can admire the result (files flash-cs3-shape-tweening-tear.*)

Anyhow, the idea is that for some shape transformations, you should learn how to to transform shapes. See the Flash object transform tutorial

Some design tips

• You should consider doing a shape transform in several steps, i.e. use several shape tweens in a row.
• You can put several shape tweens in different layers. E.g. I added a "background" shape tween to the above animation. It's a simple rectangle with 2 different color gradients.

You can admire the result (files flash-cs3-shape-tweening-tear2.*)

Links

Example materials

Example files used (including *.fla source) can be found here:

http://tecfa.unige.ch/guides/flash/ex/shape-tweening-intro/

• Click on either an *.html or *.swf file to see.
• Get just the *.fla file if you want to make modifications. The standard copyright of this wiki applies.