To start animating a document in Flash we must first cover the basic principles of animation and how animation works.
What is Animation?
As you may have already learned, animation is the rapid display of sequential still images that when displayed fast enough give the illusion of motion. In Flash we call each of these still images a Frame. This illusion of motion is caused by a concept known as "persistence of vision". Our brain retains an image for a brief moment so when we see a series of still images our brain fills in the gaps between the images giving us the sense of fluid motion. Studies have shown that using a frame rate of less than 16 frames per second can cause the mind to see flashing images. Though we can still perceive motion at slower rates our brains are able to detect the series of still images and not fluid motion.
It is important for us to familiarize ourselves with how traditional films are made in order to understand how Flash creates animations. Most of the terminology used in Flash is the same as the terminology used by filmmakers.
- Frame(s): Refers to the still images that when shown sequentially create the illusion of animation.
- FPS: Stands for Frames Per Second. When the fps number is lower than 16 the human brain can perceive motion
- KeyFrame: Keyframes are the drawings which define a movement. In the workflow of traditional hand-drawn animation, the senior or key artist would draw the keyframes. After testing and approval of the rough animation, the scene would be handed over to their assistant. In Flash, the keyframes represent the starting and ending points for tweens.
- Playhead: The Playhead moves through the timeline to indicate the current frame displayed on the stage. To move the playhead you can left-click and drag it along the timeline header
- Tweening: Is short for "in-betweening" which is the process of generating intermediate frames between two images to give the appearance that the first image evolves into the second image.
- Motion Tween: Uses tweening to create animation between two Keyframes. A Motion Tween requires that the object being "tweened" be converted to a graphic and that the physical matter shape of the shape is not changed through out the process.
- Shape Tween: Is like the motion tween in that it generates all the required frames to create the sense of motion however a shape tween can have its physical characteristics manipulated.
Guide Layer: The guide layer is used to control the movement of an object in a motion tween.
Now that you have a fair understanding you can try to create a basic animation. Below is a Step-by-step guide to help you create a very simple animation using two Keyframes and a motion tween.
Step-by-Step, a simple animation
The steps you take to create this simple animation will be the basic steps you will take in creating any animation in the future. For this project we will be using the shape tool to create an ellipse which will travel across the stage. Click on the example below to see how your final document should turn out.
Step one: If you haven't created a new document, do so now. We will start by selecting the oval tool from the tool box.
Click and drag an oval onto the left side of the stage in the off stage area. We are using an oval as an example. You could also use the paintbrush to create a drawing to animate.
Step two: Right click on frame 30. If done correctly you should see several options, select Insert Keyframe. If nothing appears when you right click it is probably because you a clicking in the timeline header and not on the actual frame.
You should now have a timeline that looks like this:
If your oval is not already selected when you create your new Keyframe, left click on frame 30 to select your oval. Once your shape is selected, left click and drag your shape using your selection tool to the right side of the stage. Your shape on frame 30 should now be located here:
Step three: After creating the two Keyframes we are going to have Flash animate our oval by creating a motion tween. Right click anywhere in the grey area between the two keyframes. Select Create Motion Tween.
After you create the motion tween, the area that was once grey should now be purple with a dotted black line running through it. This means that we are half way there and Flash needs us to convert our graphic into a Graphic Symbol.
Step four: To finish creating the motion tween right click on the last Keyframe and select: Create Motion Tween
You should now have a solid black arrow running through your frames. It should look like this:
Thats it! We have now created an animation. You can either view your animation by moving the red Playhead in the time line or going to Control > Test Movie from the pull down menu.