Apple Motion 4 - Manual (Page 484)

HUD Controls
The HUD lets you adjust the Ramp’s Start Value, End Value, and Curvature parameters,
as well as change the parameter assignment.
Related Behaviors
• Oscillate
• Rate
Randomize
Creates a continuous sequence of randomly increasing and decreasing values, based on
the parameters defining the range and type of values that are generated.
Although the values created with this behavior appear to be random, they’re actually
predetermined by the parameter settings you’ve chosen. As long as you don’t change
the parameters, the frame-by-frame values created by this behavior remain the same. If
you don’t like the values that were randomly generated, click the Generate button in the
Behaviors tab in the Inspector to pick a new random seed number. This number is used
to generate a new sequence of values.
The Apply Mode parameter determines how values generated by this behavior are
combined with other behaviors and keyframes that affect the same parameter. This
provides you with different ways of using a Randomize behavior to modify a parameter’s
preexisting values.
The Randomize behavior is useful for creating jittery effects, such as twitchy rotation,
flickering opacity, and other effects requiring rapid and varied changes over time that
would be time-consuming to keyframe. The Randomize behavior can be modified with
other behaviors, such as Average and Negate, to exercise further control over the values
being generated.
Parameters in the Inspector
Amount/Multiplier: This parameter is set to Amount when the Apply Mode is set to Add,
Subtract, or Add and Subtract, and is set to Multiplier when the Apply Mode is set to
Multiply. This parameter defines the maximum value the Randomize behavior will generate.
Apply Mode: A pop-up menu that determines how values generated by this behavior
are combined with other behaviors and keyframes that affect the same parameter. This
provides you with different ways of using a Randomize behavior to modify a parameter’s
preexisting values. The options are Add, Subtract, Multiply, or Add and Subtract.
Frequency: A slider that lets you adjust the amount of random variation per second.
Higher values will generate faster variations, whereas lower values will generate slower
variations.
Noisiness: Adds an additional overlay of random variance to the Frequency you’ve set.
Higher Noisiness values result in more erratic variations in the affected parameter.
484 Chapter 9 Using Behaviors