HapFACS 3.0: FACS-Based Facial Expression Generator for 3D Speaking Virtual Characters

With the growing number of researchers interested in modeling the inner workings of affective social intelligence, the need for tools to easily model its associated expressions has emerged. The goal of this article is two-fold: 1) we describe HapFACS, a free software and API that we developed to provide the affective computing community with a resource that produces static and dynamic facial expressions for three-dimensional speaking characters; and 2) we discuss results of multiple experiments that we conducted in order to scientifically validate our facial expressions and head animations in terms of the widely accepted Facial Action Coding System (FACS) standard, and its Action Units (AU). The result is that users, without any 3D-modeling nor computer graphics expertise, can animate speaking virtual characters with FACS-based realistic facial expression animations, and embed these expressive characters in their own application(s). The HapFACS software and API can also be used for generating repertoires of realistic FACS-validated facial expressions, useful for testing emotion expression generation theories.