The basics of composition

The composition is the basis of the video. Each composition has its own timeline. Typically, a composition contains several layers that represent components such as video and audio sequences, animated text and vector graphics, still images and light sources. You can add a video sequence to a composition by creating a layer for which that video sequence will be the source. You can arrange the layers of a composition in space and time, and you can also use transparency to specify which parts of the layers you want to display on top layers. (See Layers and Properties and Transparency and Composition.)

Start rendering the composition to create frames of the movie, which are encoded and exported to any format. (See Rendering and export basics.)

Simple projects may contain only one composition; complex projects may contain hundreds of compositions to create a large-volume video sequence or many effects.

In some places in the After Effects user interface, a composition is abbreviated to “comp.

There is a corresponding entry for each composition in the Project panel. To open a composition in a separate Timeline panel, double-click the corresponding entry in the Project panel. To select a song in the Project panel, right-click (Windows) or press the CONTROL key (Mac OS) in the Composition panel or Timeline panel and choose Open Song in Project from the context menu.

Use the Composition panel to view the composition and modify its contents manually. The Composition panel contains the composition frame and an area of the timeline outside the frame that you can use to move layers in and out of the frame. Protruding segments of layers – areas outside the composition frame – are displayed as rectangular outlines. To preview and output the final result, only the area inside the composition frame is rendered.

When working with a complex project, it’s easiest to organize it by nesting compositions, that is, by transferring one or more compositions into another. You can create a composition from any number of layers with a pre-composition. After editing some layers, you can assemble them into a pre-composition, and then pre-render and replace them with the finished movie. (See Pre-composition, nesting and pre-rendering.)

You can use the Composition Navigator and the graphical mini composition view to navigate through the hierarchy of nested compositions. (See Opening and navigating between nested compositions.)

To view the structure of a complex song or network of songs, use the Graphics view panel.

Timeline button.

Click this button, located at the bottom of the Composition panel, to activate the Timeline panel of the current song.
Note.

Press the backslash () key to switch between the composition panel and the timeline panel of the current song.

Composition Button

Press this button, located at the top right of the Timeline panel, to activate the Composition panel of the current song.
Graphic Presentation button

Click this button, located at the bottom of the Composition panel, to activate the Graphic Presentation panel of the current composition.
Creating a composition
You can change the composition settings at any time. However, settings such as aspect ratio and frame size are recommended to be set when creating the composition, based on the parameters of the expected final movie. Since After Effects uses these composition settings to perform certain calculations, changing them later in the workflow can affect the final result.

When you create a composition without changing the settings in the Composition Settings dialog box, the new composition uses the settings of the previous one.

Creating a composition and adjusting settings manually
Choose Composition > New Composition or press CTRL+N (Windows) or COMMAND+N (Mac OS).
Creating a composition from a single video sequence
Drag the video sequence to the Create New Composition button at the bottom of the Project panel, or choose New Composition from Selection from the File menu.
The composition settings, such as frame size (width and height) and pixel proportion, are automatically set according to the characteristics of the video sequence.

Creating a single composition from multiple video sequences
Select a video sequence in the Project panel.
Drag the selected video sequences to the Create New Composition button at the bottom of the Project panel, or choose New Composition from Selection from the File menu.
Select Single Composition and other settings in the Create Composition from Selected Items dialog box.