Virtual Reality and Mixed Reality

Travel is a challenging task in virtual reality applications due to space constraints of the setup or limited range of the tracking systems. This prevents the user from moving away from the installation and requires developers to implement smart solutions that overcome these limitations. Some of these solutions, known as virtual locomotion techniques, try to mimic real walking movements, while others introduce some kind of magic. We developed a model that is meant to classify and sort these techniques as regards to their fidelity to real walking. This can be useful both for research, to find opportunities for new techniques, and for development, to find the technique that best fits a target application. Whereas previous works typically divide techniques into real and virtual classes, we propose a 12-point scale where all techniques fit into and therefore makes easier to compare and select techniques. Besides, we perform a retrospective analysis of a previous travel technique evaluation using this tool. Comparing the results of the experiment with the proposed fidelity scale allows us to both evaluate the proposal and find ways of improving it in future revisions.

When users experience immersive Virtual Reality (VR), the limited physical space available can become a significant problem when they use their real walk to navigate the virtual environment (VE). To address this limitation, various interfaces and metaphors have been proposed that combine different user inputs ranging from controllers, gestures, and body tracking. However, not all of these solutions are natural and intuitive, reducing the level of immersion and presence in VR. In this paper, we present Walking Seat (WS), a novel leaning interface (LI) for locomotion in VEs that the user can operate while seated. The main objective of this work is to design an interface that provides an intuitive and immersive locomotion experience. The WS interface uses pressure mapping and a gyroscope to track the user’s upper body tilt and waist orientation. The WS interface has been thoroughly evaluated, using an articulated locomotion testbed and compared its performance with three non-leaning interfaces previously tested with the same reference protocol. The experimental results suggest that the WS interface could be a promising solution for navigation in immersive VR applications and open new directions for further research to refine and improve the WS interface for more complex tasks and scenarios.

The portability of mobile virtual reality (VR) head-mounted displays (HMDs) allows users to immerse themselves in a virtual environment wherever they want at any physical place. While mobile VR has the potential to become ubiquitous as smartphones, it is still rarely used. Social acceptability is an important factor determining the usage of mobile technology. Previous work suggests that VR HMDs are considered not socially acceptable during social interaction. However, it is still unknown why the acceptance of mobile VR is reduced when being surrounded by other people. Therefore, we conducted two studies to investigate if and how interruptions by bystanders while wearing a mobile VR HMD contribute to reduced social acceptability. In the first study, we performed an observation in natural environments to find out how people interrupt VR users. In the second study, we used the same set of scenarios in an online survey to gather the opinions of a larger user group. Our results reveal still high skepticism towards VR use in public spaces, which can be mitigated partly by VR experience.

Time experience is an essential part of one’s perception of any environment, real or virtual. In this paper, from a virtual environment design perspective, we explore how rhythmic stimuli can influence an unrelated cognitive task regarding time experience and performance in virtual reality. The task involves sorting 3D objects by shape, with varying rhythmic stimuli in terms of their tempo and sensory channel (auditory and/or visual) in different trials, to collect subjective measures of time estimation and judgment. The results indicate different effects on time experience and performance depending on the context, such as user fatigue and trial repetition. Depending on the context, a positive impact of audio stimuli or a negative impact of visual stimuli on task performance can be observed, as well as time being underestimated concerning tempo in relation to task familiarity. However, some effects are consistent regardless of context, such as time being judged to pass faster with additional stimuli or consistent correlations between participants’ performance and time experience, suggesting flow-related aspects. This could be of great interest for designing virtual environments, as purposeful stimuli can strongly influence task performance and time experience, both essential components of virtual environment user experience.

Augmented Reality (AR) and Mixed Reality (MR) enable superimposing digital content onto the real world. These technologies have now matured to a point where low-code/no-code editors for AR development have emerged. However, existing collections of design principles for AR often fall short, either being too generic or overly focused on low-level details. This makes it challenging to identify the essential patterns necessary for creating captivating AR experiences. This paper addresses this issue by introducing high-level AR design patterns encompassing fundamental concepts for crafting immersive AR experiences. Event-Condition-Action rules are leveraged as a generic abstraction from the reactive behavior of AR software systems to establish a unified framework. AR-specific behavioral patterns and augmentation patterns are presented in detail. Additionally, a uniform pattern diagram schema is proposed that ensures consistent presentation and technology-agnostic documentation of AR design patterns, facilitating their effective use in design and creation of AR applications.

Due to the improved mobility it provides, wireless virtual reality has become a promising technology used in a multitude of applications, ranging from casual gaming and film animation to remote tourism and medical assistance. However, it faces a diverse set of constraints, from both a technical and a user experience standpoint, with varying requirements depending on the application. To overcome these constraints, it is important to have a clear overview of the wireless virtual reality system as well as an in-depth understanding of the end-to-end video transmission pipeline. In this paper, we propose a plug-and-play open-source wireless virtual reality benchmarking platform that is able to perform fine-grained measurements directly within a complete pipeline. This platform can be used to detect critical bottlenecks and anomalies within the system. In addition, the platform facilitates the choice of optimal parameters for a specific application. The source code of this work is publicly available and should be seen as a first step to encourage the use of open-source benchmarking tools within the virtual reality community.

In medical education, anatomy is typically taught through lectures, cadaver dissection, and using replicas. Advances in VR technology facilitated the development of specialized VR tools for teaching, training, and other tasks. They can provide highly interactive and engaging learning environments where students can immersively and repeatedly inspect and interact with virtual 3D anatomical structures. Moreover, multi-user VR environments can be employed for collaborative learning, which may enhance the learning experience. Concrete applications are still rare, though, and the effect of collaborative learning in VR has not been adequately explored yet. Therefore, we conducted a user study with \(n=\) 33 participants to evaluate the effectiveness of virtual collaboration on the example of anatomy learning (and compared it to individual learning). For our study, we developed an UE4-based multi-user VR anatomy learning application. Our results show that our VR Anatomy Atlas provides an engaging learning experience and is very effective for anatomy learning, individually as well as collaboratively. However, interestingly, we could not find significant advantages for collaborative learning regarding learning effectiveness or motivation, even though the multi-user group spent more time in the learning environment. Although rather high for the single-user condition, the usability tended to be lower for the multi-user group. This may be due to the more complex environment and a higher cognitive load. Thus, more research in collaborative VR for anatomy education is needed to investigate, if and how it can be employed more effectively.

We present XRmol, a prototype web application, based on the WebXR standard, for visualizing 3D proteins and nucleic acids. The work represents a contribution to the investigation of the potential stemming from the AR paradigm coupled with the use of personal smartphones and features a number of solutions for improving access, portability, and use in different contexts. A first pilot study with 14 volunteers outlines its potential for integration into daily lab activities and use in educational contexts.

It requires an elaborated set of measurements to assess how the performance of tasks conducted in VR is composed. Flow is a measurement widely used in other domains as a predictor of performance and has been shown to be positively correlated with performance. However, some previous works indicate that flow might bring different results in VR than in traditional environments. It is not well known for VR environments how this phenomenon relates to usability, workload, and presence. Therefore, this work reports on an experiment that allows positioning flow among the other measurements, using a spatially distributed task. The results suggest that flow correlates negatively with performance, workload, and presence, which supports VR-specific previous work while it contradicts findings from other domains. Flow is positively correlated with usability in this experiment, which is in line with expectations from previous work.

Mixed Reality (MR) technology has gained popularity in the manufacturing industry over the last few decades. In the maintenance field, it helps workers in document analysis and decision-making during operations. While numerous studies have demonstrated the empirical benefits of MR, few have examined its applicability in a real industrial context. Among them, many focus on user performance. The novelty of our work is to evaluate mainly the acceptance of MR technology by experienced technicians using smart glasses for maintenance tasks in a real industrial context. We conducted a user study involving 7 workers who were asked to follow the instructions provided by an MR Technical Documentation (MRTD) developed considering authoring guidelines already validated in the literature but only in a laboratory context. The industrial operators performed both navigation tasks within the menu of the MRTD and a disassembly task, following the instructions displayed on the smart glass. The evaluation in the real working scenario showed that MRTD is highly appreciated by workers even if they have no previous experience with smart glasses. These results allow us to confirm the goodness of the design guidelines followed for the authoring of the MRTD.

Changes in concentration performance after short-term virtual reality training in e-athletes Abstract. E-sports, or electronic sports, have emerged as a popular form of competition in the digital age. With growing involvement from well-known and established enterprises, e-sports has grown into a thriving industry. Being a professional e-athlete has become a dream for many young people. A crucial aspect of e-athletic performance is the level of cognitive functions, including concentration performance and reaction time. Both conventional and virtual reality trainings have been shown to improve these skills. In this study, 66 amateur e-athletes (45 males, 21 females, mean age 22.7 ± 0.66) who confirmed in a pre- study questionnaire that they were active amateur athletes (with no participation in professional e-sports competitions) were selected to evaluate the effectiveness of training in virtual reality (VR) on concentration performance. Participants were randomly divided into E - experimental group (n = 32) and C - control group (n = 34), with a similar number of men and women in both groups (E = 9 females and 23 males, C = 12 females and 22 males). Differences in daily gaming time and e-sports experience between groups E and C were not statistically significant. The study group underwent 15-min training sessions in the VR game, Beat Saber, for eight consecutive weekdays. The study found that training in VR improved concentration performance, demonstrating the potential of VR as a valuable tool for e-athletes to enhance their cognitive functions.

This paper highlights the significance of Extended Reality (XR) technology as a crucial component of future first responder (FR) training to address the challenges faced by Europe in maintaining public safety and peace. XR, which includes virtual reality (VR), augmented reality (AR), and mixed reality (MR), offers unique opportunities to enhance FR training. We present a mapping of specific training goals to different XR solutions, categorizing them based on immersion level and extent of world knowledge. We discuss the benefits of XR, while also acknowledging the challenges and ethical considerations. Lastly, we discuss the main future developments we deem to be crucial for the field. With this, we hope to foster a common understanding of terminology, needs and future directions between end-users, researchers and tech-providers.

The biophilic design of virtual workplaces consists of introducing additional natural elements in the virtual environment (VE) with respect to those needed for the main task. It has received increasing attention in recent years, and an increasing number of studies are showing that exposure to biophilic elements in an immersive VE produces positive effects on human well-being. However, in the literature, there are no guidelines about the setting of the different variables of biophilic design in a VE. In this work, we investigated one of these variables, i.e., the effect of the animations of biophilic elements, formulating the following research question: how do animations of biophilic virtual elements affect user attention while performing a working task? We carried out an experiment in which users performed two levels of difficulty of the n-Back cognitive test in three VEs: two identical biophilic VE, one with all static elements and another one in which some of these elements were animated, and an additional empty VE used as a baseline. Performance measurements, eye-tracking measurements, and subjective measurements were collected from 24 users. We found that introducing animations of biophilic elements does not affect user performance in the cognitive task. Furthermore, we found that users’ gaze remains fixed on the main task for more than 94% of the time. However, the use of animations does not bring added value to users in terms of user experience, whereas it causes an increase in perceived distraction and mental effort.