Parent and child layers



To synchronize changes to layers by assigning one layer’s transformations to another layer, use parenting. After a layer is made a parent to another layer, the other layer is called the child layer. When you assign a parent, the transform properties of the child layer become relative to the parent layer instead of to the composition. For example, if a parent layer moves 5 pixels to the right of its starting position, then the child layer also moves 5 pixels to the right of its position. Parenting is similar to grouping; transformations made to the group are relative to the anchor point of the parent.

Parenting affects all transform properties except Opacity: Position, Scale, Rotation, and (for 3D layers) Orientation.

A layer can have only one parent, but a layer can be a parent to any number of layers in the same composition.

You can animate child layers independent of their parent layers. You can also parent using null objects, which are hidden layers.

You cannot animate the act of assigning and removing the parent designation—that is, you cannot designate a layer as a parent at one point in time and designate it as a normal layer at a different point in time.

When you create a parenting relationship, you can choose whether to have the child take on the transform property values of the parent or retain its own. If you choose to have the child take on the transform property values of the parent, the child layer jumps to the parent’s position. If you choose to have the child retain its own transform property values, then the child stays where it is. In both cases, subsequent changes to the transform property values of the parent are applied to the child. Similarly, you can choose whether the child jumps when the parenting relationship is removed.

Dragging the pick whip in the Timeline panel to designate the planet layer as the parent to the saucer layer

Note: To show or hide the Parent column in the Timeline panel, choose Columns > Parent from the Timeline panel menu.
  • To parent a layer, in the Parent column, drag the pick whip from the layer that is to be the child layer to the layer that is to be the parent layer.
  • To parent a layer, in the Parent column, click the menu of the layer that you want to be the child, and choose a parent layer name from the menu.
  • 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.

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: