Showing the ghost outlines of the Ball at preceding Keyframes is called Onion Skinning. This
is an aid to positioning and reshaping Strokes as the Animation is constructed (more on this
later).
At this point Keyframes have been inserted in the Timeline at Frames 1, 15 and 30. Figure 11.13
Keyframes
Jump to First Frame
Play (the Animation)
You may click the Jump to First Frame button followed by the Play the button to see a very jerky
simulation or click, hold and drag the Timeline Cursor to Scrub the Animation. In either case the
Ball will jump from its position at Frame 1 to Frame 15 then on to Frame 30. With the Play button
activated the Timeline Cursor continues to move until it reaches Frame 250 then jumps back to
frame 1 and proceeds to repeat the play. Obviously refinement is required,
When the Play button is activated it changes to a
Stop button which you may press at any time.
Figure 11.14
When the Animation Action was mapped out, Keyframes KF 4 and KF 5 were included. When the
Ball contacts the Surface it will compress on impact then go back to its original shape as it
bounces up. Including this in the Animation is an example of a minute refinement to create
realism. This will be included at this point but bear in mind the action will still be jerky until it is
smoothed out.
Position the Timeline Cursor at Frame 17. In the 3D View Editor, in Edit Mode, with the Ball
selected, Scale the down on the Z Axis and position the Ball just touching the Surface. Move the
Timeline Cursor to frame 19 and reshape the Ball (Scale Up on the Z Axis).
Scale down on the Z Axis
Reshape the Ball (Scale up on the Z Axis)
Figure 11.15
Frame 17
Frame 19
114