Micro and macro facial expressions by driven animations in realistic Virtual Humans

TL;DR

This paper investigates how using facial tracking to animate virtual humans affects emotion perception, finding that it reduces accuracy compared to artist-created animations, thus impacting realism and perception.

Contribution

It extends previous studies by analyzing macro and micro expressions in virtual humans animated via facial tracking, contrasting with traditional blendshape methods.

Findings

Facial tracking animations decrease emotion recognition accuracy.

Artist-created animations yield more accurate emotion perception.

Micro and macro expressions are perceived differently depending on animation method.

Abstract

Computer Graphics (CG) advancements have allowed the creation of more realistic Virtual Humans (VH) through modern techniques for animating the VH body and face, thereby affecting perception. From traditional methods, including blend shapes, to driven animations using facial and body tracking, these advancements can potentially enhance the perception of comfort and realism in relation to VHs. Previously, Psychology studied facial movements in humans, with some works separating expressions into macro and micro expressions. Also, some previous CG studies have analyzed how macro and micro expressions are perceived, replicating psychology studies in VHs, encompassing studies with realistic and cartoon VHs, and exploring different VH technologies. However, instead of using facial tracking animation methods, these previous studies animated the VHs using blendshapes interpolation. To understand how the facial tracking technique alters the perception of VHs, this paper extends the study to macro and micro expressions, employing two datasets to transfer real facial expressions to VHs and analyze how their expressions are perceived. Our findings suggest that transferring facial expressions from real actors to VHs significantly diminishes the accuracy of emotion perception compared to VH facial animations created by artists.