An AgentAnimation File (AAF) is a file format used by Microsoft Agent characters which stores character animations. Unlike most Microsoft Agent file formats, it cannot be opened directly. The only way to load an AAF file is by loading an ACF file created for Microsoft Agent 1.5 that references the animation.
Usage
While not directly the character themselves, AAF files contain an animation for the character. They are able to be loaded through an ACF if it requests to load the AAF file associated with a specific animation name. Since each animation is stored in separate AAF files, this allows for the ACF file to load only the specified animations in a script rather than every animation the character has, using less memory.
Structure
AAF files contain all frames in the animation (including mouth frames), the speed of each frame in the animation, all images used in an animation, and any audio which is used in that animation. However, AAF files do not contain any metadata about the character, since that is all stored in the main ACF file. AAF files can also only contain one animation, meaning two animations cannot share an AAF file.
Trivia
Not much is known about Agent Animation Files, as there is not much documentation about characters made in Microsoft Agent 1.5.
AAF files were the original file used for storing character animations in Microsoft Agent, but was randomly replaced with ACA in version 2.0.
The reason for this change is unknown, it could be either for formatting reasons, as Microsoft Agent 2.0 characters are compiled differently from Microsoft Agent 1.5 characters, or for naming convenience as most Microsoft Agent file types such as ACS, ACF, and ACD starting with the letters AC.
