Apple Motion 4 - Manual (Page 516)

Object: An image well that defines the object to be repelled from.
Strength: A slider defining the speed at which the object is repelled. With a value of 0,
the object is not repelled at all. The higher the value, the faster the object is repelled.
Falloff Type: A pop-up menu that determines whether the distance defined by the
Influence parameter falls off linearly or exponentially.
• Linear: Repulsion between objects 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 repelled, and the faster it moves away from the object doing the repelling.
Falloff Rate: This value determines how quickly the force of repulsion between objects
affected by this behavior falls off. A low Falloff Rate value results in objects quickly getting
up to speed as they move away from the object of repulsion. 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 away from the object of repulsion. Objects that are
outside of the area of influence remain in place.
Drag: A slider that can be used to reduce the distance the object or objects travel away
from the repelling object.
Include X, Y, and Z: Buttons that allow you to specify the space in which the object
moves away from the selected 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.
HUD Controls
The HUD has an image well you can use to assign an object to move away from, as well
as controls for Strength, Falloff Type, Falloff Rate, Influence, axis assignment, and Drag.
When applied to an object that contains multiple objects (such as a group, particles, text,
or the replicator), the Affect Subobjects checkbox also appears in the HUD.
Related Behaviors
• Repel
Rotational Drag
This behavior is similar to the Drag behavior, except that it affects Rotation instead of
position. Rotational Drag simulates friction affecting objects that are spinning due to
keyframed or behavior-driven changes to the Rotation parameter. By setting higher Drag
values, you can slow rotational changes to an eventual stop.
516 Chapter 9 Using Behaviors