Randomize behavior in Motion

The Randomize behavior creates a continuous sequence of randomly increasing and decreasing values, based on the parameters defining the range and type of values generated. Use Randomize to create 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.

Although the values created with this behavior appear to be random, they’re 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 randomly generated values, click the button to the right of the seed value in the Behaviors 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 can be modified with other behaviors, such as Average and Negate, to exercise further control over the values generated.

Adjust this behavior using the controls in the Behaviors Inspector:

Amount: A slider (available when the Apply Mode—described below—is set to Add, Subtract, or Add and Subtract) that defines the maximum value the Randomize behavior will generate.
Multiplier: A slider (available when the Apply Mode—described below—is set to Multiply) that 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. Choose Add, Subtract, Multiply, or Add and Subtract.
Frequency: A slider that sets the amount of random variation per second. Higher values generate faster variations; lower values generate slower variations.
Noisiness: A slider that 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.
Link: A checkbox available when you apply Randomize to a two-dimensional parameter (such as Scale) or to a three-dimensional parameter (such as Position) that consists of X, Y, and/or Z values. Select this checkbox to keep the behavior’s effect on each value proportional.
Affect Subobjects: A checkbox (available when you apply Randomize to a parameter of the Sequence Replicator behavior) that, when selected, gives each replicated cell in the canvas a different random behavior. When Affect Subobjects is deselected, each object undergoes the same animation.
Random Seed: A button that picks a new random seed number. This number is used to generate new sequences of values, based on the other parameters of this behavior.
Start Offset: A slider that delays the beginning of the behavior’s effect relative to the first frame of its position in the Timeline. Adjust this parameter to make the behavior start later. The units of this parameter are in frames.
End Offset: A slider that offsets the end of the behavior’s effect relative to the last frame of its position in the Timeline, in frames. Adjust this parameter to make the behavior stop before the end of the behavior bar in the Timeline. Using this slider to stop the effect, instead of trimming the end of the behavior bar in the Timeline, freezes the last random value generated by this behavior for the remaining duration of the object. Trimming the end of the behavior bar resets the parameter to its original value.
Apply To: A pop-up menu shows the parameter affected, and that can be used to reassign the behavior to another parameter.

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Motion User Guide

Randomize behavior in Motion