Motion Attractor
The Attractor behavior, when applied to an object, causes other objects that lie within the area of influence move toward it. You can manipulate the strength with which other objects are attracted, as well as the distance required for attraction to begin.
By default, objects overshoot the object of attraction and bounce around, never coming to rest. The Drag parameter lets you adjust this behavior, changing whether attracted objects overshoot and bounce around, or whether they eventually slow down and stop at the position of the target object.
The Attractor behavior can affect all objects in the Canvas that fall within the area of attraction, or you can limit its effect to a specific list of objects by using the Affect parameter.
The Attractor behavior can also be applied to objects in motion. If you animate the position of the target object to which you’ve applied the Attractor behavior, all other objects in the Canvas continue to be attracted to its new position.
Adjust this behavior using the controls in the Behaviors Inspector:
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Affect: A pop-up menu that limits which objects in your project are affected by the Attractor behavior. There are three options:
All Objects: All objects in the Canvas are affected by the Attractor behavior.
Related Objects: The default setting. Only other objects in the same group as the object of attraction are affected.
Specific Objects: Only objects appearing in the Affected Objects list are affected by the Attractor behavior.
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Affected Objects: A list that appears when Specific Objects is chosen in the Affect pop-up menu. Drag objects from the Layers list into this list to have the objects affected by this behavior. To remove an item from the list, select the item and click Remove. The Affected Objects list contains the following columns:
Layer: This column lists the name of the layer containing the object.
Name: This column lists the name of the object.
Strength: A slider that sets the speed at which attracted objects move toward the target object. With a value of 0, attracted objects don’t move at all. The higher the value, the faster attracted objects move.
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Falloff Type: A pop-up menu that determines whether the distance defined by the Influence parameter falls off linearly or exponentially. There are two menu items:
Linear: Object attraction falls off in proportion to the object’s distance.
Exponential: The closer an object is within the area of influence, the more strongly it is attracted, and the faster it moves toward the object of attraction.
Falloff Rate: A slider that sets how quickly the force of attraction between objects affected by this behavior falls off. A low Falloff Rate value results in objects quickly getting up to speed as they move toward the object of attraction. A high Falloff Rate causes objects to accelerate much more slowly. When set to Exponential, the attraction falls off more quickly than when set to Linear.
Influence: A slider that defines the radius of the circle of influence in pixels. Objects that fall within the area of influence move toward the object of attraction. Objects outside the area of influence remain in place.
Drag: A slider that reduces the distance attracted objects overshoot the object of attraction. Lower Drag values result in the object overshooting the object of attraction, moving past and then careening back around toward the target object again and again. Higher Drag values result in the object coming to rest sooner.
Include X, Y, and Z: Buttons that specify the space in which the object (or objects) moves toward the target object. For example, when X and Y are enabled, the object moves in the XY plane; when Y and Z are enabled, the object moves in the YZ plane.