Buddy biking: a user study on social collaboration in a virtual reality exergame for rehabilitation

AbstractEvery Virtual Reality (VR) experience has to end at some point. While there already exist concepts to design transitions for users to enter a virtual world, their return from the physical world should be considered, as well, as it is a part of the overall VR experience. We call the latter outro-transitions. In contrast to offboarding of VR experiences, that takes place after taking off VR hardware (e.g., HMDs), outro-transitions are still part of the immersive experience. Such transitions occur more frequently when VR is experienced periodically and for only short times. One example where transition techniques are necessary is in an auditorium where the audience has individual VR headsets available, for example, in a presentation using PowerPoint slides together with brief VR experiences sprinkled between the slides. The audience must put on and take off HMDs frequently every time they switch from common presentation media to VR and back. In a such a one-to-many VR scenario, it is challenging for presenters to explore the process of multiple people coming back from the virtual to the physical world at once. Direct communication may be constrained while VR users are wearing an HMD. Presenters need a tool to indicate them to stop the VR session and switch back to the slide presentation. Virtual visual cues can help presenters or other external entities (e.g., automated/scripted events) to request VR users to end a VR session. Such transitions become part of the overall experience of the audience and thus must be considered. This paper explores visual cues as outro-transitions from a virtual world back to the physical world and their utility to enable presenters to request VR users to end a VR session. We propose and investigate eight transition techniques. We focus on their usage in short consecutive VR experiences and include both established and novel techniques. The transition techniques are evaluated within a user study to draw conclusions on the effects of outro-transitions on the overall experience and presence of participants. We also take into account how long an outro-transition may take and how comfortable our participants perceived the proposed techniques. The study points out that they preferred non-interactive outro-transitions over interactive ones, except for a transition that allowed VR users to communicate with presenters. Furthermore, we explore the presenter-VR user relation within a presentation scenario that uses short VR experiences. The study indicates involving presenters that can stop a VR session was not only negligible but preferred by our participants.

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Towards estimating affective states in Virtual Reality based on behavioral data

Virtual Reality ◽

10.1007/s10055-021-00518-1 ◽

2021 ◽

Author(s):

Valentin Holzwarth ◽

Johannes Schneider ◽

Joshua Handali ◽

Joy Gisler ◽

Christian Hirt ◽

...

Keyword(s):

Virtual Reality ◽

Adaptive Systems ◽

User Study ◽

Affective State ◽

Head Movements ◽

Affective States ◽

Physical Demand ◽

Perceived Performance ◽

Sequential Administration ◽

Better Than

AbstractInferring users’ perceptions of Virtual Environments (VEs) is essential for Virtual Reality (VR) research. Traditionally, this is achieved through assessing users’ affective states before and after being exposed to a VE, based on standardized, self-assessment questionnaires. The main disadvantage of questionnaires is their sequential administration, i.e., a user’s affective state is measured asynchronously to its generation within the VE. A synchronous measurement of users’ affective states would be highly favorable, e.g., in the context of adaptive systems. Drawing from nonverbal behavior research, we argue that behavioral measures could be a powerful approach to assess users’ affective states in VR. In this paper, we contribute by providing methods and measures evaluated in a user study involving 42 participants to assess a users’ affective states by measuring head movements during VR exposure. We show that head yaw significantly correlates with presence, mental and physical demand, perceived performance, and system usability. We also exploit the identified relationships for two practical tasks that are based on head yaw: (1) predicting a user’s affective state, and (2) detecting manipulated questionnaire answers, i.e., answers that are possibly non-truthful. We found that affective states can be predicted significantly better than a naive estimate for mental demand, physical demand, perceived performance, and usability. Further, manipulated or non-truthful answers can also be estimated significantly better than by a naive approach. These findings mark an initial step in the development of novel methods to assess user perception of VEs.

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Low-Asymmetry Interface for Multiuser VR Experiences with Both HMD and Non-HMD Users

Sensors ◽

10.3390/s21020397 ◽

2021 ◽

Vol 21 (2) ◽

pp. 397

Author(s):

Qimeng Zhang ◽

Ji-Su Ban ◽

Mingyu Kim ◽

Hae Won Byun ◽

Chang-Hun Kim

Keyword(s):

Virtual Reality ◽

Virtual Environment ◽

Mobile Device ◽

User Satisfaction ◽

Virtual World ◽

User Study ◽

Visual Display ◽

Point Of View ◽

Head Mounted Display ◽

And Behavior

We propose a low-asymmetry interface to improve the presence of non-head-mounted-display (non-HMD) users in shared virtual reality (VR) experiences with HMD users. The low-asymmetry interface ensures that the HMD and non-HMD users’ perception of the VR environment is almost similar. That is, the point-of-view asymmetry and behavior asymmetry between HMD and non-HMD users are reduced. Our system comprises a portable mobile device as a visual display to provide a changing PoV for the non-HMD user and a walking simulator as an in-place walking detection sensor to enable the same level of realistic and unrestricted physical-walking-based locomotion for all users. Because this allows non-HMD users to experience the same level of visualization and free movement as HMD users, both of them can engage as the main actors in movement scenarios. Our user study revealed that the low-asymmetry interface enables non-HMD users to feel a presence similar to that of the HMD users when performing equivalent locomotion tasks in a virtual environment. Furthermore, our system can enable one HMD user and multiple non-HMD users to participate together in a virtual world; moreover, our experiments show that the non-HMD user satisfaction increases with the number of non-HMD participants owing to increased presence and enjoyment.

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UNDERSTANDING UNDERWATER PHOTOGRAMMETRY FOR MARITIME ARCHAEOLOGY THROUGH IMMERSIVE VIRTUAL REALITY

ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences ◽

10.5194/isprs-archives-xlii-2-w10-85-2019 ◽

2019 ◽

Vol XLII-2/W10 ◽

pp. 85-91 ◽

Cited By ~ 3

Author(s):

M. Doležal ◽

M. Vlachos ◽

M. Secci ◽

S. Demesticha ◽

D. Skarlatos ◽

...

Keyword(s):

Virtual Reality ◽

Educational Software ◽

User Study ◽

Data Gathering ◽

Maritime Archaeology ◽

Archaeological Sites ◽

Immersive Virtual Reality ◽

Digital Form ◽

3D Mesh ◽

Initial Results

<p><strong>Abstract.</strong> Underwater archaeological discoveries bring new challenges to the field, but such sites are more difficult to reach and, due to natural influences, they tend to deteriorate fast. Photogrammetry is one of the most powerful tools used for archaeological fieldwork. Photogrammetric techniques are used to document the state of the site in digital form for later analysis, without the risk of damaging any of the artefacts or the site itself. To achieve best possible results with the gathered data, divers should come prepared with the knowledge of measurements and photo capture methods. Archaeologists use this technology to record discovered arteacts or even the whole archaeological sites. Data gathering underwater brings several problems and limitations, so specific steps should be taken to get the best possible results, and divers should well be prepared before starting work at an underwater site. Using immersive virtual reality, we have developed an educational software to introduce maritime archaeology students to photogrammetry techniques. To test the feasibility of the software, a user study was performed and evaluated by experts. In the software, the user is tasked to put markers on the site, measure distances between them, and then take photos of the site, from which the 3D mesh is generated offline. Initial results show that the system is useful for understanding the basics of underwater photogrammetry.</p>

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3D virtual reality vs. 2D desktop registration user interface comparison

PLoS ONE ◽

10.1371/journal.pone.0258103 ◽

2021 ◽

Vol 16 (10) ◽

pp. e0258103

Author(s):

Andreas Bueckle ◽

Kilian Buehling ◽

Patrick C. Shih ◽

Katy Börner

Keyword(s):

Virtual Reality ◽

User Interface ◽

Human Tissue ◽

User Study ◽

Human Subjects ◽

Target Object ◽

Virtual Space ◽

Colon Tissue ◽

Position Accuracy ◽

Downstream Analysis

Working with organs and extracted tissue blocks is an essential task in many medical surgery and anatomy environments. In order to prepare specimens from human donors for further analysis, wet-bench workers must properly dissect human tissue and collect metadata for downstream analysis, including information about the spatial origin of tissue. The Registration User Interface (RUI) was developed to allow stakeholders in the Human Biomolecular Atlas Program (HuBMAP) to register tissue blocks—i.e., to record the size, position, and orientation of human tissue data with regard to reference organs. The RUI has been used by tissue mapping centers across the HuBMAP consortium to register a total of 45 kidney, spleen, and colon tissue blocks, with planned support for 17 organs in the near future. In this paper, we compare three setups for registering one 3D tissue block object to another 3D reference organ (target) object. The first setup is a 2D Desktop implementation featuring a traditional screen, mouse, and keyboard interface. The remaining setups are both virtual reality (VR) versions of the RUI: VR Tabletop, where users sit at a physical desk which is replicated in virtual space; VR Standup, where users stand upright while performing their tasks. All three setups were implemented using the Unity game engine. We then ran a user study for these three setups involving 42 human subjects completing 14 increasingly difficult and then 30 identical tasks in sequence and reporting position accuracy, rotation accuracy, completion time, and satisfaction. All study materials were made available in support of future study replication, alongside videos documenting our setups. We found that while VR Tabletop and VR Standup users are about three times as fast and about a third more accurate in terms of rotation than 2D Desktop users (for the sequence of 30 identical tasks), there are no significant differences between the three setups for position accuracy when normalized by the height of the virtual kidney across setups. When extrapolating from the 2D Desktop setup with a 113-mm-tall kidney, the absolute performance values for the 2D Desktop version (22.6 seconds per task, 5.88 degrees rotation, and 1.32 mm position accuracy after 8.3 tasks in the series of 30 identical tasks) confirm that the 2D Desktop interface is well-suited for allowing users in HuBMAP to register tissue blocks at a speed and accuracy that meets the needs of experts performing tissue dissection. In addition, the 2D Desktop setup is cheaper, easier to learn, and more practical for wet-bench environments than the VR setups.

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Examining User Perception of the Size of Multiple Objects in Virtual Reality

Applied Sciences ◽

10.3390/app10114049 ◽

2020 ◽

Vol 10 (11) ◽

pp. 4049 ◽

Cited By ~ 1

Author(s):

Bruce H. Thomas

Keyword(s):

Virtual Reality ◽

Virtual Worlds ◽

User Study ◽

Just Noticeable Difference ◽

User Perception ◽

Multiple Objects ◽

Virtual Objects ◽

Target Values ◽

Virtual Reality Application ◽

Object Relative

This article presents a user study into user perception of an object’s size when presented in virtual reality. Critical for users understanding of virtual worlds is their perception of the size of virtual objects. This article is concerned with virtual objects that are within arm’s reach of the user. Examples of such virtual objects could be virtual controls such as buttons, dials and levers that the users manipulate to control the virtual reality application. This article explores the issue of a user’s ability to judge the size of an object relative to a second object of a different colour. The results determined that the points of subjective equality for height and width judgement tasks ranging from 10 to 90 mm were all within an acceptable value. That is to say, participants were able to perceive height and width judgements very close to the target values. The results for height judgement task for just-noticeable difference were all less than 1.5 mm and for the width judgement task less than 2.3 mm.

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Different Types of Users, Different Types of Immersion: A User Study of Interaction Design and Immersion in Consumer Virtual Reality

IEEE Consumer Electronics Magazine ◽

10.1109/mce.2018.2816218 ◽

2018 ◽

Vol 7 (4) ◽

pp. 36-43 ◽

Cited By ~ 5

Author(s):

Jonathan Harth ◽

Alexandra Hofmann ◽

Mike Karst ◽

David Kempf ◽

Annelie Ostertag ◽

...

Keyword(s):

Virtual Reality ◽

Interaction Design ◽

User Study ◽

Different Types

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BioMove: Biometric User Identification from Human Kinesiological Movements for Virtual Reality Systems

Sensors ◽

10.3390/s20102944 ◽

2020 ◽

Vol 20 (10) ◽

pp. 2944

Author(s):

Ilesanmi Olade ◽

Charles Fleming ◽

Hai-Ning Liang

Keyword(s):

Virtual Reality ◽

User Study ◽

Eye Gaze ◽

Initial Study ◽

Physical World ◽

Penetration Testing ◽

Machine Learning Classification ◽

Model Classification ◽

Movement Characteristics ◽

Identification Confidence

Virtual reality (VR) has advanced rapidly and is used for many entertainment and business purposes. The need for secure, transparent and non-intrusive identification mechanisms is important to facilitate users’ safe participation and secure experience. People are kinesiologically unique, having individual behavioral and movement characteristics, which can be leveraged and used in security sensitive VR applications to compensate for users’ inability to detect potential observational attackers in the physical world. Additionally, such method of identification using a user’s kinesiological data is valuable in common scenarios where multiple users simultaneously participate in a VR environment. In this paper, we present a user study (n = 15) where our participants performed a series of controlled tasks that require physical movements (such as grabbing, rotating and dropping) that could be decomposed into unique kinesiological patterns while we monitored and captured their hand, head and eye gaze data within the VR environment. We present an analysis of the data and show that these data can be used as a biometric discriminant of high confidence using machine learning classification methods such as kNN or SVM, thereby adding a layer of security in terms of identification or dynamically adapting the VR environment to the users’ preferences. We also performed a whitebox penetration testing with 12 attackers, some of whom were physically similar to the participants. We could obtain an average identification confidence value of 0.98 from the actual participants’ test data after the initial study and also a trained model classification accuracy of 98.6%. Penetration testing indicated all attackers resulted in confidence values of less than 50% (<50%), although physically similar attackers had higher confidence values. These findings can help the design and development of secure VR systems.

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Comparing VR- and AR-Based Try-On Systems Using Personalized Avatars

Electronics ◽

10.3390/electronics9111814 ◽

2020 ◽

Vol 9 (11) ◽

pp. 1814

Author(s):

Yuzhao Liu ◽

Yuhan Liu ◽

Shihui Xu ◽

Kelvin Cheng ◽

Soh Masuko ◽

...

Keyword(s):

Virtual Reality ◽

Augmented Reality ◽

Mobile Application ◽

User Study ◽

User Studies ◽

Apparel Shopping ◽

Shopping Experience ◽

Online Experience ◽

The Impact ◽

Virtual Body

Despite the convenience offered by e-commerce, online apparel shopping presents various product-related risks, as consumers can neither physically see nor try products on themselves. Augmented reality (AR) and virtual reality (VR) technologies have been used to improve the shopping online experience. Therefore, we propose an AR- and VR-based try-on system that provides users a novel shopping experience where they can view garments fitted onto their personalized virtual body. Recorded personalized motions are used to allow users to dynamically interact with their dressed virtual body in AR. We conducted two user studies to compare the different roles of VR- and AR-based try-ons and validate the impact of personalized motions on the virtual try-on experience. In the first user study, the mobile application with the AR- and VR-based try-on is compared to a traditional e-commerce interface. In the second user study, personalized avatars with pre-defined motion and personalized motion is compared to a personalized no-motion avatar with AR-based try-on. The result shows that AR- and VR-based try-ons can positively influence the shopping experience, compared with the traditional e-commerce interface. Overall, AR-based try-on provides a better and more realistic garment visualization than VR-based try-on. In addition, we found that personalized motions do not directly affect the user’s shopping experience.

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