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Frequency: A slider that lets you adjust the amount of random variation per second.
Higher values generate faster variations, whereas lower values generate slower variations.
Wriggle Offset: A slider that allows you to offset the sequence of random values when
you want to apply the same Wriggle behavior to multiple shapes. By offsetting each
shape’s version of the Wriggle behavior, you can prevent them from moving in sync.
Noisiness: This slider adds an additional overlay of random variance to the Frequency
you’ve set. Higher Noisiness values result in more erratic variations in the affected vertices.
Link: This parameter appears when you apply this behavior to a two-dimensional
parameter (such as Distort) or three-dimensional parameter (such as Position or Rotation)
that consists of X, Y, and/or Z values. Select this checkbox to keep the behavior’s effect
on each value proportional.
Preserve Angle: When this checkbox is selected, the tangent handles become (or remain)
flat, maintaining the continuity of the curves.
Random Seed: A button that lets you pick a new random seed number. This number is
used to randomly generate new sequences of values, based on the other parameters of
this behavior.
HUD Controls
The Wriggle Shape HUD contains the Amount, Multiplier, Apply To, Frequency, Wriggle
Offset, Noisiness, Link, and Preserve Angle parameters.
Write On
The Write On behavior provides a quick way to draw a paint stroke or outline on the
Canvas over time. This allows you to create a handwritten text effect, create the
ever-popular old serial travel map effect, create a hand-sketched alpha mask for a transition
or reveal, create an animated graph for a business presentation, produce graphics to
prevent monitor burn-ins, and so on. The behavior can be applied to a paint stroke created
with the Paint Stroke tool or added to an existing shape. You can have the shape draw,
erase, draw and erase, draw in reverse, and so on, over time.
When Write On is applied to a filled shape with an outline, only the outline of the shape
is drawn.
Note: You can manually animate the First Point Offset and Last Point Offset parameters
in the Style pane of the Shape Inspector to achieve the same effect as the Write On
behavior.
Parameters in the Inspector
Shape Outline: This pop-up menu determines whether the stroke is drawn, erased, or
drawn and erased.
• Draw: Draws the stroke over the duration of the behavior.
1186 Chapter 20 Using Shapes, Masks, and Paint Strokes