Adobe After Effects CS4 - Manual (Page 173)

167 USING AFTER EFFECTS CS4
Layers and properties
Last updated 12/21/2009
• To remove a parent from a layer, in the Parent column, click the menu of the layer to remove the parent from, and
choose None.
• To extend the selection to include all child layers of a selected parent layer, right-click (Windows) or Control-click
(Mac OS) the layer in the Composition or Timeline panel, and choose Select Children.
• To make a child layer jump when a parent is assigned or removed, hold down Alt (Windows) or Option (Mac OS)
as you assign or remove the parent.
• To remove a parent from a layer (that is, set Parent to None), Ctrl-click (Windows) or Command-click (Mac OS)
the parenting pick whip of the child layer in the Timeline panel. Alt+Ctrl-click (Windows) or Option+Command-
click (Mac OS) the parenting pick whip of the child layer to remove the parent and cause the child layer to jump.
More Help topics
“ Columns ” on page 17
Online resources about parent and child layers
Paul Tuersley provides a script on the AE Enhancers forum for duplicating a parent layer and all of its children,
preserving the parenting hierarchy.
Angie Taylor provides a character animation tutorial on her Creative After Effects website that shows how to use
parenting and expressions. Angie provides a more extensive discussion and explanation of animation using parenting,
expressions, and null object layers in a PDF excerpt from her book
Creative After Effects 7: Workflow Techniques for
Animation, Visual Effects, and Motion Graphics .
Trish and Chris Meyer provide an introduction to parenting in a PDF excerpt from the “Parenting and Nesting”
chapter of their book
After Effects Apprentice: Real-World Skills for the Aspiring Motion Graphics Artist .
Guy Chen provides a simple project on the After Effects Exchange on the Adobe website that demonstrates the
animation of several 3D layers arranged as a cube, controlled by a parent null layer.
Carl Larsen provides a video tutorial on the Creative COW website that demonstrates how to use expressions and
parenting to relate the rotation of a set of wheels to the horizontal movement of a vehicle.
Carl Larsen provides a pair of video tutorials on the Creative COW website in which he explains the basics of parenting
and then uses an expression involving the
toWorld method to trace the path of an animated child layer:
• part 1
• part 2
Null object layers
To assign a parent layer, but keep that layer from being a visible element in your project, use a null object. A null object
is an invisible layer that has all the properties of a visible layer so that it can be a parent to any layer in the composition.
Adjust and animate a null object as you would any other layer. You use the same commands to modify settings for a
null object that you use for a solid-color layer (Layer
> Solid Settings).
You can apply Expression Controls effects to null objects and then use the null object as a control layer for effects and
animations in other layers. For example, when working with a camera or light layer, create a null object layer and use
an expression to link the Point Of Interest property of the camera or light to the Position property of the null layer. Then,
you can animate the Point Of Interest property by moving the null object. It is often easier to select and see a null object
than it is to select and see the point of interest.