To Sit or Not to Sit in VR: Analyzing Influences and (Dis)Advantages of Posture and Embodied Interaction

Leaning-Based Interfaces Improve Simultaneous Locomotion and Object Interaction in VR Compared to the Handheld Controller

Physical walking is often considered the gold standard for VR travel whenever feasible. However, limited free-space walking areas in the real-world do not allow exploring larger-scale virtual environments by actual walking. Therefore, users often require handheld controllers for navigation, which can reduce believability, interfere with simultaneous interaction tasks, and exacerbate adverse effects such as motion sickness and disorientation. To investigate alternative locomotion options, we compared handheld Controller (thumbstick-based) and physical walking versus a seated (HeadJoystick) and standing/stepping (NaviBoard) leaning-based locomotion interface, where seated/standing users travel by moving their head toward the target direction. Rotations were always physically performed. To compare these interfaces, we designed a novel simultaneous locomotion and object interaction task, where users needed to keep touching the center of upward moving target balloons with their virtual lightsaber, while simultaneously staying inside a horizontally moving enclosure. Walking resulted in the best locomotion, interaction, and combined performances while the controller performed worst. Leaning-based interfaces improved user experience and performance compared to Controller, especially when standing/stepping using NaviBoard, but did not reach walking performance. That is, leaning-based interfaces HeadJoystick (sitting) and NaviBoard (standing) that provided additional physical self-motion cues compared to controller improved enjoyment, preference, spatial presence, vection intensity, motion sickness, as well as performance for locomotion, object interaction, and combined locomotion and object interaction. Our results also showed that less embodied interfaces (and in particular the controller) caused a more pronounced performance deterioration when increasing locomotion speed. Moreover, observed differences between our interfaces were not affected by repeated interface usage.

Interacting with virtual characters, objects and environments: investigating immersive virtual reality in rehabilitation

PURPOSE

This pilot study aimed to (a) investigate opportunities for immersive Virtual Reality (VR) technology in communication, physical, and visual rehabilitation by examining the interaction of people without disabilities in a range of structured virtual environments; and (b) validate research protocols that might be used to evaluate the physical, visual, and verbal interaction of users in virtual worlds, and their safety while using the technology.

METHODS

Thirteen adults identifying as people without disability were exposed to VR via a head-mounted display. A video-review method was used to qualitatively code and analyse each participant's communication, movement, orientation, and support needs.

RESULTS

All participants oriented to their virtual environments sufficiently to use applications. Their spoken language was effective for interaction, although unconventional social behaviours were also observed. Two participants reported minor adverse reactions consistent with mild cybersickness.

CONCLUSION

The results provide insight into the types of environments and characters that support the greatest communicative, physical, and visual interaction in immersive VR. The tested protocols are useful to assess safety when using VR, and to observe communicative, physical, and visual interaction with virtual environments and characters. Implications for future research and use of VR with people with communication, physical and visual disability are discussed.

Sitting or Standing in VR: About Comfort, Conflicts, and Hazards

This article examines the choices between sitting and standing in virtual reality (VR) experiences, addressing conflicts, challenges, and opportunities. It explores issues such as the risk of motion sickness in stationary users and virtual rotations, the formation of mental models, consistent authoring, affordances, and the integration of embodied interfaces for enhanced interactions. Furthermore, it delves into the significance of multisensory integration and the impact of postural mismatches on immersion and acceptance in VR. Ultimately, the article underscores the importance of aligning postural choices and embodied interfaces with the goals of VR applications, be it for entertainment or simulation, to enhance user experiences.

Modified Egocentric Viewpoint for Softer Seated Experience in Virtual Reality

Users in a prolonged experience of virtual reality adopt a sitting position according to their task, as they do in the real world. However, inconsistencies in the haptic feedback from a chair they sit on in the real world and that which is expected in the virtual world decrease the feeling of presence. We aimed to change the perceived haptic features of a chair by shifting the position and angle of the users' viewpoints in the virtual reality environment. The targeted features in this study were seat softness and backrest flexibility. To enhance the seat softness, we shifted the virtual viewpoint using an exponential formula soon after a user's bottom contacted the seat surface. The flexibility of the backrest was manipulated by moving the viewpoint, which followed the tilt of the virtual backrest. These shifts make users feel as if their body moves along with the viewpoint; as a result, they would perceive pseudo-softness or flexibility consistently with the body movement. Based on subjective evaluations, we confirmed that the participants perceived the seat as being softer and the backrest as being more flexible than the actual ones. These results demonstrated that only shifting the viewpoint could change the participants' perceptions of the haptic features of their seats, although significant changes created strong discomfort.

Immersive movies: the effect of point of view on narrative engagement

Cinematic virtual reality (CVR) offers filmmakers a wide range of possibilities to explore new techniques regarding movie scripting, shooting and editing. Despite the many experiments performed so far both with both live action and computer-generated movies, just a few studies focused on analyzing how the various techniques actually affect the viewers’ experience. Like in traditional cinema, a key step for CVR screenwriters and directors is to choose from which perspective the viewers will see the scene, the so-called point of view (POV). The aim of this paper is to understand to what extent watching an immersive movie from a specific POV could impact the narrative engagement (NE), i.e., the viewers’ sensation of being immersed in the movie environment and being connected with its characters and story. Two POVs that are typically used in CVR, i.e., first-person perspective (1-PP) and external perspective (EP), are investigated through a user study in which both objective and subjective metrics were collected. The user study was carried out by leveraging two live action 360° short films with distinct scripts. The results suggest that the 1-PP experience could be more pleasant than the EP one in terms of overall NE and narrative presence, or even for all the NE dimensions if the potential of that POV is specifically exploited.