A largely forgotten plugin - MSPhysics. Also not so easy to get running under SUp2022: https://community.sketchucation.com/user/faust07

Animation data are stored in the model. All data related to movements, cameras and visual effects refer to objects of the model via a unique ID. The .animator file is simply a backup file, in case something is corrupted in the model. The fromat is a serialization of the working data structures in the plugin. So, not really designed for a clean export. Exporting the animation would first require that you are able to export the container objects (Groups, ComponentInstance), with their transformations.