Revisiting Micro and Macro Expressions in Computer Graphics Characters

TL;DR

The paper addresses how realism level and historical era affect perception of micro and macro facial expressions in virtual humans. It reproduces two prior studies using a 2023 realistic VH and online experiments to compare against a 2021 cartoon VH and results from 2014, 2014–2023. Key findings show that micro expressions are more readily recognized on realistic VHs than on cartoon VHs ($p=0.03$), while cross-era micro recognition (2014 vs 2023) shows no significant difference ($p>0.05$); macro expressions are recognized robustly across conditions, and micro-then-macro sequences yield higher accuracy than micro-before-macro, particularly for realistic VHs ($p=0.01$). These results inform CG character design by clarifying how realism and temporal presentation influence emotion perception, with implications for viewer engagement and the uncanny valley in applied settings.

Abstract

This paper presents the reproduction of two studies focused on the perception of micro and macro expressions of Virtual Humans (VHs) generated by Computer Graphics (CG), first described in 2014 and replicated in 2021. The 2014 study referred to a VH realistic, whereas, in 2021, it referred to a VH cartoon. In our work, we replicate the study by using a realistic CG character. Our main goals are to compare the perceptions of micro and macro expressions between levels of realism (2021 cartoon versus 2023 realistic) and between realistic characters in different periods (i.e., 2014 versus 2023). In one of our results, people more easily recognized micro expressions in realistic VHs than in a cartoon VH. In another result, we show that the participants' perception was similar for both micro and macro expressions in 2014 and 2023.

Figures (3)

• Figure 1: All expressions represented by the realistic character presented in our work.
• Figure 2: All expressions represented by the cartoon character presented in Andreotti et al. andreotti2021perception work.
• Figure 3: All expressions represented by the realistic character presented in Queiroz et al. queiroz2014investigating work in 2014.