Investigating the Effects of Appearance and Animation Realism on the Perception of Expressive Photorealistic Virtual Humans

Abstract

Currently, digital assistants are predominantly limited to the modality of audio or text. As technology is moving at a rapid pace however, we can soon expect them to adopt full artificial human appearances. Investigating the perception of these virtual humans can help guide designers to better engineer these artificial digital humans that are to take on the roles of digital companions. In the past, numerous research studies have investigated the perception of virtual humans under the lens of appearance realism and animation realism among other characteristics. However, virtual humans formerly termed photorealistic, cannot be called as such under today’s standards anymore. While previously, it was a well-established fact that photorealistic characters elicit the uncanny valley phenomenon - recent research investigations have challenged this by re-opening research questions and making use of new state-of-the-art photorealistic digital human models. This paper aims to contribute towards this research effort by investigating main and interaction effects of appearance realism and animation realism for expressive virtual humans. In a study with 62 participants, there were statistically significant effects of appearance realism for social presence. Additionally, animation realism as well as appearance realism played a significant effect on perceived discomfort towards the virtual human. Finally, evidence hints at higher animation realism being received significantly better when paired with photorealistic characters.