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• Front Face: Defines the front edge (in Z space) for the collision.
Width: A slider that allows you to define a width (the right and left edges of the Canvas)
other than the size of project. By default, Width is set to the project size.
Height: A slider that allows you to define a height (the top and bottom edges) other
than the size of project. By default, Height is set to the project size.
Depth: A slider that allows you to define a depth (the back and front faces, in Z space)
for the edge collision. By default, Depth is set to 100 pixels.
HUD Controls
The HUD has controls for Bounce Strength and Width, Height, and Depth. 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.
Gravity
This behavior causes an object, or the objects in a group (when Affect Subobjects is
selected), to fall over time. The gravitational acceleration can be increased or decreased,
resulting in a change to the rate of fall. Objects affected by the Gravity behavior continue
to fall past the bottom edge of the Canvas (unless the Edge Collision behavior has been
applied).
The following illustration shows an object affected by the Throw, Snap Alignment to
Motion, and Gravity behaviors all at once.
As you can see, the Gravity behavior can be used in conjunction with other behaviors
that animate the position of objects to create natural-looking arcs and animation paths
that simulate thrown objects falling to the ground. For example, apply the Throw behavior
to an object to send it flying through the air, and then apply the Gravity behavior to it to
make the object arc up and then fall down past the bottom of the Canvas.
463Chapter 9 Using Behaviors