Virtual characters that appear almost photo-realistic have been shown to induce negative responses from viewers in traditional media, such as film and video games. This effect, described as the uncanny valley, is the reason why realism is often avoided when the aim is to create an appealing virtual character. In Virtual Reality, there have been few attempts to investigate this phenomenon and the implications of rendering virtual characters with high levels of realism on user enjoyment. In this paper, we conducted a large-scale experiment on over one thousand members of the public in order to gather information on how virtual characters are perceived in interactive virtual reality games. We were particularly interested in whether different render styles (realistic, cartoon, etc.) would directly influence appeal, or if a character's personality was the most important indicator of appeal. We used a number of perceptual metrics such as subjective ratings, proximity, and attribution bias in order to test our hypothesis. Our main result shows that affinity towards virtual characters is a complex interaction between the character's appearance and personality, and that realism is in fact a positive choice for virtual characters in virtual reality.

Recent advances in rendering and data-driven animation have enabled the creation of compelling characters with impressive levels of realism. While data-driven techniques can produce animations that are extremely faithful to the original motion, many challenging problems remain because of the high complexity of human motion. A better understanding of the factors that make human motion recognizable and appealing would be of great value in industries where creating a variety of appealing virtual characters with realistic motion is required. To investigate these issues, we captured thirty actors walking, jogging and dancing, and applied their motions to the same virtual character (one each for the males and females). We then conducted a series of perceptual experiments to explore the distinctiveness and attractiveness of these human motions, and whether characteristic motion features transfer across an individual's different gaits. Average faces are perceived to be less distinctive but more attractive, so we explored whether this was also true for body motion. We found that dancing motions were most easily recognized and that distinctiveness in one gait does not predict how recognizable the same actor is when performing a different motion. As hypothesized, average motions were always amongst the least distinctive and most attractive. Furthermore, as 50% of participants in the experiment were Caucasian European and 50% were Asian Korean, we found that the latter were as good as or better at recognizing the motions of the Caucasian actors than their European counterparts, in particular for dancing males, whom they also rated more highly for attractiveness.

In recent years, the quality of real-time rendering has reached new heights—realistic reflections, physically based materials, and photometric lighting are all becoming commonplace in modern game engines and even interactive virtual environments, such as virtual reality (VR). As the strive for realism continues, there is a need to investigate the effect of photorealism on users’ perception, particularly for interactive, emotional scenarios in VR. In this article, we explored three main topics, where we predicted photorealism will make a difference: the illusion of being present with the virtual person and in an environment, altered emotional response toward the character, and a subtler response—comfort of being in close proximity to the character. We present a perceptual experiment, with an interactive expressive virtual character in VR, which was designed to induce particular social responses in people. Our participant pool was large (N = 797) and diverse in terms of demographics. We designed a between-group experiment, where each group saw either the realistic rendering or one of our stylized conditions (simple and sketch style), expressing one of three attitudes: Friendly, Unfriendly, or Sad. While the render style did not particularly effect the level of comfort with the character or increase the illusion of presence with it, our main finding shows that the photorealistic character changed the emotional responses of participants, compared to the stylized versions. We also found a preference for realism in VR, reflected in the affinity and higher place illusion in the scenario, rendered in the realistic render style.

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according to the gender of the character's motion. Our findings have implications for the design of virtual characters in interactive virtual environments.