Adobe After Effects - Manual (Page 640)

Note:
Note:
Because writing the ID to a file is considered a modification, the modification date of a source file may be updated the first time the file is
imported.
Working with XMP metadata in After Effects
The Metadata panel
In After Effects, the Metadata panel (Window > Metadata) shows static metadata only. Project metadata is shown at the top of the panel, and Files
metadata is shown at the bottom. Temporal metadata is visible in After Effects only as layer markers.
Project metadata is shown in the Metadata panel as soon as you open the panel. You can add and change information in any of the metadata
categories. This information shows up in Bridge when the project file is selected and is also embedded in files rendered and exported using the
render queue when the Include Source XMP Metadata output module option is selected.
To see Files metadata in the Metadata panel, you must first select a file in the Project panel. You can then add or change information in any of the
metadata categories. If you select multiple files, then changes that you make will be made in all of the selected files. Any changes made to source
file metadata are immediately written to the source files.
To change which metadata categories and fields are shown in the Metadata panel, choose Project Metadata Display Preferences or Files
Metadata Display Preferences from the Metadata panel menu.
Conversion of XMP metadata to layer markers
When you create a layer based on a footage item that contains XMP metadata, the temporal metadata can be converted to layer markers.
To enable the automatic conversion of XMP metadata to layer markers, select the Create Layer Markers From Footage XMP Metadata
preference in the Media & Disk Cache preferences category.
During this conversion, After Effects shows a “Reading XMP markers from footage” status message.
These layer markers are fully editable, just as any other layer markers. (See Layer markers and composition markers.)
Changes made to the layer markers based on the source file’s XMP metadata do not affect the XMP metadata in the source file.
To restore the layer markers for a layer to those read from the layer’s source’s XMP metadata, right-click (Windows) or Control-click (Mac OS)
any marker on the layer and choose Update Markers From Source. This command also removes any markers that you have added to the layer.
You can use this command to manually create layer markers from XMP metadata if you did not have the Create Layer Markers From Footage
XMP Metadata preference selected when you created the layer.
For information on using expressions together with the contents of layer markers, see MarkerKey attributes (expression reference).
Exporting XMP metadata from After Effects
When you render and export a composition, you can write XMP metadata to the output file that includes all of the XMP metadata from the sources
for that composition. This includes all of the composition markers and layer markers in the composition, all of the XMP metadata from the source
files on which the layers in the composition are based, comments from the Comments columns in the Timeline panel and Project panel, and the
project-level XMP metadata for the project in which the composition is contained. XMP metadata from nested compositions is recursively
processed and included in the output.
To write all of the XMP metadata to the output file, select Include Source XMP Metadata in the output module settings for the output file. If Include
Source XMP Metadata is deselected, the only XMP metadata that is written to the output file is a unique ID. (See Output modules and output
module settings.)
When Include Source XMP Metadata is on, in some cases, rendering and exporting can take a long time because of the time that it takes
to read and assemble XMP metadata from the source files. For this reason, the option is off by defa
In addition to storing XMP metadata in After Effects project (.aep, .aepx) files and source documents used by Adobe applications (for example,
.psd), After Effects can write XMP metadata directly into the files for many container formats, including the following:
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