Precompose layers – Adobe After Effects User Manual
Page 76
Leave All Attributes In
Move All Attributes Into The New Composition
Preferences and composition settings that affect nested compositions
Because a precomposition is itself a layer, you can control its behavior using layer switches and composition switches in the Timeline panel. You
can choose whether changes made to the switches in the containing composition are propagated to the nested composition. To prevent layer
switches from affecting nested compositions, choose Edit > Preferences > General (Windows) or After Effects > Preferences > General (Mac OS),
and then deselect Switches Affect Nested Comps.
In the Advanced tab of the Composition Settings dialog box (Composition > Composition Settings), choose Preserve Resolution When Nested or
Preserve Frame Rate When Nested Or In Render Queue for a composition to retain its own resolution or frame rate, and not inherit those settings
from the containing composition. For example, if you deliberately used a low frame rate in a composition to create a jerky, hand-animated result,
you should preserve the frame rate for that composition when it is nested. Similarly, the results of rotoscoping may look wrong when converted to
a different frame rate or resolution. Use this setting instead of the Posterize Time effect, which is less efficient.
Jeff Almasol provides a script on his
makes toggling the Preserve Resolution When Nested or Preserve Frame Rate
When Nested Or In Render Queue preference setting more convenient.
Changing the current time in one panel updates the current time in other panels associated with that composition. By default, the current time is
also updated for all compositions related to the current composition by nesting. To prevent compositions related by nesting from updating their
current times when you change the current time in one composition, deselect the Synchronize Time Of All Related Items preference (Edit >
Preferences > General (Windows) or After Effects > Preferences > General (Mac OS)).
Online resources about precomposing and nesting
Angie Taylor provides an extensive discussion and explanation of animation using nesting, parenting, expressions, and null object layers in a PDF
excerpt from her book
Chris and Trish Meyer provide an introduction to precomposing and nesting in a PDF excerpt from the “Parenting and Nesting” chapter of their
book
Chris and Trish Meyer share tips on setting up a composition hierarchy so that making changes in a project is easier
the Un-Precompose script, which extracts layers from a precomposition.
the Zorro-The Layer Tagger script, which allows you to group layers in your composition using tags rather
than precomposing.
Precompose layers
Precomposing layers places them in a new composition (sometimes called a precomposition), which replaces the layers in the original composition.
Precomposing a single layer is useful for adding transform properties to a layer and influencing the order in which elements of a composition are
rendered.
1. Select the layers in the Timeline panel, and choose Layer > Pre-compose or press Ctrl+Shift+C (Windows) or Command+Shift+C (Mac OS).
2. Select one of the following:
Leaves the properties and keyframes of the precomposed layer in the original composition, applied to the new layer
that represents the precomposition. The frame size of the new composition is the same as the size of the selected layer. This option is not
available when you select more than one layer, a text layer, or a shape layer.
Moves the properties and keyframes of the precomposed layers one level further from the
root composition in the composition hierarchy. When you use this option, changes you applied to the properties of the layers remain with the
individual layers within the precomposition. The frame size of the new composition is the same as the frame size of the original composition.
Jeff Almasol provides a script on his
that precomposes selected layers to the duration of the selected layers, with options for
72