Users can interact in virtual reality (VR) spaces through avatars that differ markedly from their real-world looks. These avatars can be customized to any appearance and size, whether they are based on real entities or are entirely fictitious. These avatars include non-humanoid avatars as well. Some non-humanoid avatars do not have hands, in which case the problem arises that they cannot reference using gesture. In this case, the interlocutor must determine the object from the direction of the referent's gaze and the context. Given the impact of avatar characteristics on the visual communication process of joint attention among users, it is essential to elucidate the connection between avatar traits and the range of reference to facilitate smooth interaction. In this study, the influence of avatar looks on the referential range of demonstrative indicators was elucidated. Experiments were conducted in a VR spaces using avatars of different appearances and sizes, with the aim of understanding how these differences impact the ability to refer to objects using both distal and proximal indicators. Specifically, the study aimed to identify the transition point from the proximal to the distal referential field for each type of avatar. This research seeks to deepen the understanding of how avatars, as proxies for humans in VR spaces, influence communication dynamics. Looking forward, it is anticipated that the findings will enhance the VR experience by improving referential communication among avatars of diverse appearances and sizes. This enhancement is expected to foster richer user interactions, thereby contributing to the future growth of the VR market.
This paper introduces our investigation into driving behaviors during emergency operations, such as entering an intersection on a red traffic light, to compare and analyze behavior differences based on the driver's emergency driving experience and skills. As a preliminary step, we developed a VR-based simulator that replicates emergency driving scenarios, in consultation with firefighters. Drivers with varied levels of experience and skill in emergency driving executed emergency driving maneuvers using this VR simulator, during which the system recorded their behaviors, including eye movement, head orientation, throttle and brake positions, and steering angle. Our analysis revealed distinct behavioral differences based on experience and skill; for example, professional firefighters repeatedly decelerated, briefly stopped, and checked both left and right sides before entering the intersection.
Discrepancies between an avatar's movements in virtual space and participants' movements in the real world can degrade the quality of the virtual reality (VR) experience. One prominent form of such a discrepancy is delay. Many previous studies have investigated the acceptable delay between head-tracking and landscape rendering, or the delay of the seen user's hand movements. However, the minimum detectable delay during full-body movements, particularly those involving significant changes in viewpoint, has not yet been fully investigated. In this study, the detection threshold for delays between participants' real-world movements, where the head and viewpoint positions move substantially, and corresponding avatar movements in virtual space was investigated. In the experiment, participants wearing VR goggles performed stand-up motions. Corresponding stand-up motion of the avatar in the VR space involved the delay of up to 300 ms. Participants looked at the avatar's movements through the mirror placed in front of him/her in the VR space. The detection thresholds of five individuals were investigated using psychophysical method of constant stimuli. In the experiment, the participants answered whether the avatar's movements delayed or did not delay comparing with their own movements. The mean detection threshold, at which the participant reports the presence of delay for 50% of all the time, was found to be 129.70 ms, with a 95% confidence interval of 31.59 ms. These findings provide some insights for designers of VR applications.
The evaluations of Locomotion Techniques (LTs) provide information regarding the advantages and shortcomings of LTs for navigating in Virtual Reality (VR). While the primary approach is to assess the LTs separately (e.g., comparing walking versus steering versus teleportation), little is known about how LTs can be used simultaneously (i.e., how users navigate when several options are offered), especially in different VR setups. This paper aimed to investigate the influence of real and virtual environment size on LT usage during VR navigation for the first time. We conducted a user study (n=24), where participants had to explore a virtual garden and pick up mushrooms. Participants could choose to walk, steer, or teleport. We varied the size of the virtual environment as well as the size of the user's physical workspace. We found that users' LT usage depends on the VR setup. For instance, they tend to do more displacements with teleportation (which was users' favorite technique overall) but would rather walk or steer when the size of the virtual environment is the same as the workspace. This work contributes to understanding user behavior in VR, particularly regarding LT usage, which tends to be an overlooked topic.
For virtual reality (VR) training and learning applications, post-intervention assessment serves as a means to validate the effectiveness of the designed practice. These assessments can occur in the virtual environment by embedding questionnaires and necessary response mechanisms. Researchers have explored embedded VR (in-VR) assessment to minimize disruption to immersion and interference with the user's sense of presence compared to 2D screen-based (out-VR) surveys. However, the influence of in-VR assessment formats on user experience and performance still needs to be explored. Therefore, we conducted a within-group study (N = 25) to compare three assessment formats on task load, usability, user experience, self-efficacy, and performance metrics (i.e., completion time, movement, and response correctness). Using an educational application focused on charged particles and electric fields, we observed no significant differences in self-reported user experience metrics across the in-VR assessment formats. However, participants achieved higher scores when interacting with the 3DStatic assessment. This preference for 3DStatic assessment highlights the advantages of 3D visualizations in VR over traditional 2D user interfaces.
In this paper, we propose a competitive game in which a player wearing an augmented reality (AR) head-mounted display (HMD) and a player not wearing an HMD share not only a virtual environment but also the structure of a physical environment. Through the proposed game, we explore the interaction between players in an online multiplayer game using an AR HMD, which is enjoyable and has a high social presence. For this exploration, we created a game design that actively utilizes a physical environment and the asymmetry between players wearing and not wearing an HMD. We implemented the designed game and conducted a user study (n=14) to evaluate the game using the Game Experience Questionnaire and an our own questionnaire. The results revealed that the players had a highly positive affect toward the game and showed a high social presence. We also obtained insights into how to make the game more interesting and to increase social presence of players.
