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Extended reality (XR) technologies, such as virtual reality (VR) and augmented reality (AR), provide users, their avatars, and embodied agents a shared platform to collaborate in a spatial context. Although traditional face-to-face communication is limited by users’ proximity, meaning that another human’s non-verbal embodied cues become more difficult to perceive the farther one is away from that person, researchers and practitioners have started to look into ways to accentuate or amplify such embodied cues and signals to counteract the effects of distance with XR technologies. In this article, we describe and evaluate the Big Head technique, in which a human’s head in VR/AR is scaled up relative to their distance from the observer as a mechanism for enhancing the visibility of non-verbal facial cues, such as facial expressions or eye gaze. To better understand and explore this technique, we present two complimentary human-subject experiments in this article. In our first experiment, we conducted a VR study with a head-mounted display to understand the impact of increased or decreased head scales on participants’ ability to perceive facial expressions as well as their sense of comfort and feeling of “uncannniness” over distances of up to 10 m. We explored two different scaling methods and compared perceptual thresholds and user preferences. Our second experiment was performed in an outdoor AR environment with an optical see-through head-mounted display. Participants were asked to estimate facial expressions and eye gaze, and identify a virtual human over large distances of 30, 60, and 90 m. In both experiments, our results show significant differences in minimum, maximum, and ideal head scales for different distances and tasks related to perceiving faces, facial expressions, and eye gaze, and we also found that participants were more comfortable with slightly bigger heads at larger distances. We discuss our findings with respect to the technologies used, and we discuss implications and guidelines for practical applications that aim to leverage XR-enhanced facial cues.
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Effects of a Distracting Background and Focal Switching Distance in an Augmented Reality System
Many augmented reality (AR) applications require observers to shift their gaze between AR and real-world content. To date, commercial optical see-through (OST) AR displays have presented content at either a single focal distance, or at a small number of fixed focal distances. Meanwhile, real-world stimuli can occur at a variety of focal distances. Therefore, when shifting gaze between AR and real-world content, in order to view new content in sharp focus, observers must often change their eye’s accommodative state. When performed repetitively, this can negatively affect task performance and eye fatigue. However, these effects may be under reported, because past research has not yet considered the potential additional effect of distracting real world backgrounds.An experimental method that analyzes background effects is presented, using a text-based visual search task that requires integrating information presented in both AR and the real world. An experiment is reported, which examined the effect of a distracting background versus a blank background, at focal switching distances of 0, 1.33, 2.0, and 3.33 meters. Qualitatively, a majority of the participants reported that the distracting background made the task more difficult and fatiguing. Quantitatively, increasing the focal switching distance resulted in reduced task performance and increased eye fatigue. However, changing the background, between blank and distracting, did not result in significant measured differences. Suggestions are given for further efforts to examine background effects.
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- Award ID(s):
- 1937565
- PAR ID:
- 10316626
- Date Published:
- Journal Name:
- Proceedings of the Workshop on Perceptual and Cognitive Issues in XR (PERCxR), IEEE International Symposium on Mixed and Augmented Reality Adjunct (ISMAR-Adjunct)
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Conference Paper:
- https://doi.org/10.1109/ISMAR-Adjunct54149.2021.00029
