Adobe After Effects CS4 - Manual (Page 649)

643 USING AFTER EFFECTS CS4
Plug-ins, scripts, and automation
Last updated 12/21/2009
Scripts
A script is a series of commands that tells an application to perform a series of operations. You can use scripts in most
Adobe applications to automate repetitive tasks, perform complex calculations, and even use some functionality not
directly exposed through the graphical user interface. For example, you can direct After Effects to reorder the layers in
a composition, find and replace source text in text layers, or send an e-mail message when rendering is complete.
After Effects scripts use the Adobe ExtendScript language, which is an extended form of JavaScript, similar to Adobe
ActionScript®. ExtendScript files have the .jsx or jsxbin filename extension.
For a complete description of the scripting capabilities available with After Effects, see the After Effects Scripting Guide
on the
After Effects Developer Center section of the Adobe website.
For a list of changes to the scripting interface between After Effects CS3 and After Effects CS4, see Todd Kopriva's blog .
Loading and running scripts
When After Effects starts, it loads scripts from the Scripts folder. By default, the Scripts folder is in the following
location:
• (Windows) Program Files\Adobe\Adobe After Effects CS4\Support Files
• (Mac OS) Applications/Adobe After Effects CS4
Several Scripts come with After Effects and are automatically installed in the Scripts folder.
Loaded scripts are available from the File > Scripts menu. If you edit a script while After Effects is running, you must
save your changes for the changes to be applied. If you place a script in the Scripts folder while After Effects is running,
you must restart After Effects for the script to appear in the Scripts menu, though you can immediately run the new
script using the Run Script File command.
Scripts in the ScriptUI Panels folder are available from the bottom of the Window menu. If a script has been written
to provide a user interface in a dockable panel, the script should be put in the ScriptUI folder. ScriptUI panels work
much the same as the default panels in the After Effects user interface.
Note: The default is for scripts to not be allowed to write files or send or receive communication over a network. To allow
scripts to write files and communicate over a network, choose Edit > Preferences > General (Windows) or After Effects >
Preferences > General (Mac OS), and select the Allow Scripts To Write Files And Access Network option.
• To run a loaded script, choose File > Scripts > [script name].
• To run a script that has not been loaded, choose File > Scripts > Run Script File, locate and select a script, and click Open.
• To run a script from the command line, call afterfx.exe from the command line. Use the -r switch and the full path
of the script to run as arguments. This command does not open a new instance of the After Effects application; it
runs the script in the existing instance.
Example (for Windows):
afterfx -r c:\script_path\example_script.jsx
You can use this command-line technique—together with the software that comes with a customizable keyboard—
to bind the invocation of a script to a keyboard shortcut.
Jeff Almasol provides a set of scripts that includes the Launch Pad script, which creates a docking panel from which
you can run any other scripts that you have installed. The same package of Jeff’s scripts includes KeyEd Up, a script
with which you can modify keyboard shortcuts. For information, see the
Adobe After Effects Exchange on the Adobe
website.