As private virtual reality (VR) use increases, so do injuries from real-world collisions. Beyond physical harm, both actual collisions and the fear of colliding may affect the user experience, particularly presence, which can be considered a core aspect of VR. In two studies, we examined the relationship between presence, collision anxiety (CA), and real collisions during VR use. Our results indicate that collisions themselves do not significantly reduce presence but do increase CA. Furthermore, while presence was not a significant predictor of CA, we replicated prior findings that disorientation in the physical environment heightens collision anxiety. These findings suggest that disorientation and (fear of) collisions affect fundamental aspects of VR experiences. Hence, the results highlight the importance of considering the users’ subjective feeling of safety when designing for safe VR use, not only to minimize the risk of injuries but also to maximize the user experience.

Social virtual reality (VR) applications enable users to experience highly immersive mediated interactions and social experiences. Especially embodied nonverbal communication, like mediated social touch, is mostly unique to social VR and potentially a major factor in enabling fulfilling emotional experiences at a distance. In our within-subjects study ($N = 28$), we compared feedback from wearable vibrotactile haptic devices with two established visual presentation forms of social touch: clipping and pseudo-haptics. Our findings suggest that the addition of haptic feedback can elicit significantly higher emotional arousal and result in a stronger illusion of touch than visual presentations alone. In contrast to existing literature, there was no evidence of a difference between the immersive and emotional experience of clipping and pseudo-haptics in our sample. In addition, we also investigated whether simply wearing haptic feedback devices during a social touch interaction, i.e., without active haptic feedback, affects the illusion of touch and user experience. However, there was no evidence of a significant effect in the sample studied. A free copy of this paper, including the appendix, is available at https://doi.org/10.17605/OSF.IO/4FYKQ.

The imprisonment of parents has severe consequences for their relationship to their children. Thus, ensuring valuable contact between them is crucial for parent's social rehabilitation and children's development and well-being. However, visits are often not child-friendly and lack interaction. We see social VR as a means to address these issues. In this paper, we share findings of a user-centered design process of a virtual reality application that allows imprisoned parents to meet their children. Our pilot study with four dyads of children and imprisoned fathers revealed that both appreciated the virtual visits, felt close to each other, and had a positive emotional experience, although fathers missed physical contact. Children preferred VR's playful and interactive nature compared to regular visits. Our research presents virtual visits as a suitable alternative to ensure valuable social interaction between prisoners and their children and contribute to the potential of immersive virtual social experiences for sensitive use cases.

Virtual reality (VR) applications achieve their high immersive potential by detaching the user from the real world, replacing it through a virtual environment. This detachment also blocks real-world orientation cues, which might cause fear of colliding with the real environment and negatively impact the player experience. However, since collision anxiety (CA) is a relatively young concept, it is unclear how factors like users' VR expertise or specific game design choices may affect it. We defined expected CA profiles for five commercial VR games and conducted a longitudinal study examining how growing VR expertise and VR game design influence the users' CA. After six weeks and a total of 154 VR sessions, results indicate that CA differs between applications and generally decreases as VR expertise increases. Based on our results, we propose design implications, providing researchers and designers with guidelines on when to expect and how to avoid fear of colliding.

Figure 1: Player avatars search the virtual escape room for clues.

Engaging in digital games, in particular, using highly immersive VR technology, has emerged as a coping mechanism to escape negative feelings and create positive emotions. It is, therefore, interesting to investigate which mechanisms in digital games influence players’ emotions. One potential mechanism is using virtual characters as companions, as they can positively affect the emotional state and the player experience. However, the impact of the virtual character’s specific emotions on the players has been studied less. The presence of others can positively influence people and improve their well-being when in a bad emotional state. According to the Emotional Contagion theory, the presence of positive-minded others can achieve these positive effects or, following the Emotional Similarity theory, also by the presence of negative-minded others. Therefore, we want to investigate how virtual characters in different emotional states affect the players when they are sad and immerse themselves in a game. Hence, we posed the following research question: "How do different emotions of a virtual character affect emotional state, player experience, and connectedness when players are in a sad emotional state?". Our lab study with 75 participants put in a sad emotional state, revealed significant differences between playing a cooperative VR game with either a happy or a sad virtual character regarding participants’ emotional state and connectedness, but not regarding player experience. We discuss the results and implications of emotional virtual characters to enhance well-being.

The high degree of sensory immersion is a distinctive feature of head-mounted virtual reality (VR) systems. While the visual detachment from the real world enables unique immersive experiences, users risk collisions due to their inability to perceive physical obstacles in their environment. Even the mere anticipation of a collision can adversely affect the overall experience and erode user confidence in the VR system. However, there are currently no valid tools for assessing collision anxiety. We present the iterative development and validation of the Collision Anxiety Questionnaire (CAQ), involving an exploratory and a confirmatory factor analysis with a total of 159 participants. The results provide evidence for both discriminant and convergent validity and a good model fit for the final CAQ with three subscales: general collision anxiety, orientation, and interpersonal collision anxiety. By utilizing the CAQ, researchers can examine potential confounding effects of collision anxiety and evaluate methods for its mitigation.

The presence of virtual characters in digital games influences players’ experiences; however, the specific impact of various emotional states exhibited by these characters remains unclear. Theories like Emotional Contagion and Emotional Similarity seek to elucidate how the emotions of others affect our own: We might let the emotional state of others infect us, or our emotions may be intensified when others exhibit similar feelings. In the gaming context, we pondered: What impact does playing a horror game alongside a confident virtual character, compared to an anxious one, have on players’ emotional states and experiences? We conducted a lab study with 69 participants and compared a VR horror game played with either a confident or anxious virtual character or alone. Horror games were chosen for their ability to evoke intense emotions, like fear. Our results show that participants could accurately recognize the emotional states portrayed by the virtual character. The horror game significantly increased fear and positive affect, according to the nature of this genre. Not in line with expectations, there was no significant difference between groups regarding player experience and emotional state. We discuss these findings and explore implications for emotional virtual characters within and beyond gaming contexts.

Consumer social virtual reality (VR) applications have recently started to enable social interactions at a distance. Yet it is still relatively unknown if and to what extent such applications provide meaningful social experiences in cases where in-person leisure activities are not feasible. To explore this, we developed a custom social VR application and conducted an exploratory lab study with 25 dyads in which we compared an in-person and a virtual version of a co-located multiplayer scenario. Our mixed-methods analysis revealed that both scenarios created a socially rich atmosphere and strengthened the social closeness between players. However, the lack of facial animations, limited body language, and a low field of view led to VR’s main social experiential limitations: a reduced mutual awareness and emotional understanding compared to the in-person scenario. We derive implications for social VR design and research as well as game user research.

The use of simulation patient programs in the education of child and adolescent psychiatrists is limited by their low availability, high cost, and questionable authenticity and accuracy. To address this issue, we are developing a playful VR interaction with an autonomous agent, a virtual young patient with depression, providing a standardized and safe tool for medical students to practice their diagnosis skills. We follow a participatory design process and directly involve the target group in the development to ensure that the tool meets their needs. We focused on two aspects: the virtual agent's emotionality and the user-agent interaction. The user study results show actual application and agent design requirements. Further, we present the challenges of the first prototypical implementations of young agents and outline future research visions.

Motivation and high effort in exergames are still open to optimization. In reality, coaches can stimulate athletes' engagement by infecting them with their emotions. However, whether these emotion-influencing effects also occur with virtual coaches remains unclear. In the present study, we measured the emotional state, motivation, and performance (punch speed) of 47 participants playing a VR exergame with an emotional (happy/angry) or neutral virtual coach. Results show that the happy and angry coach significantly affected the players' emotions. Furthermore, interacting with the emotional coaches leads to higher motivation, whereas the angry coach causes a reduction of feeling related. Also, we found a significant positive correlation between the increase in anger and punch speed. Our results show that adding an emotional component to virtual coaches into exergames is promising for increasing motivation and performance. This study highlights the positive effects of emotional virtual characters for improving VR exergames and, therefore, players' health.

Current Social VR literature provides limited insight on one of the most critical behaviors for developing and maintaining interpersonal relationships: self-disclosure. Therefore, we present an online survey (N = 126) investigating how users disclose personal information to each other in Social VR. Our results indicate that many participants see in Social VR access to authentic connections with others despite tending towards skepticism and privacy concerns. Most users disclose sexuality-related information, lifestyle preferences, and personal goals. In contrast, information that breaks anonymity, such as real names and more intimate aspects of oneself, are shared less commonly. Thereby, self-disclosure decisions depend on factors like the relationship to or age of disclosure recipients, the privacy of a virtual environment, the group size, or the activity context, and is driven by different goals, i.a., relational development or exploration of oneself. These insights advance the understanding of current Social VR users and their behavior by directing future research on self-disclosure-based relationship building in Social VR and outlying broader design implications for the future metaverse.

Exergames can increase cognitive performance compared to sedentary games and the same non-gamified exercise. Whether this advantage can be further enhanced by the high immersion and arousal level VR systems offer remains unclear. Therefore, we developed an exergame that can be played in VR or in front of a TV screen with identical gameplay in both versions. In a study with 32 participants, we collected data on cognitive performance, arousal, presence, motivation, and exertion. Our results show no difference in cognitive performance and arousal between the conditions. However, the VR version significantly increased players' presence and motivation while significantly reducing perceived exertion. Our results help to understand in which aspects VR can have a significant impact on exergames.

Within this paper, we want to present a new game concept that combines VR technology and gaze control to direct and train attention in ADHD children. Our approach combines the motivating ability of games with attention-demanding tasks, gaze control, and the high level of immersion of Virtual Reality to design a fun training game for children with ADHD. We describe our design process and give design recommendations for creating games with gaze control and games for children with ADHD.

We present online survey results on social virtual reality (social VR) users' activities and usage motives. Based on content analysis of users' free-text responses, we found that most users, in fact, use these applications for social activities and to satisfy diverse social needs. The second most frequently mentioned categories of activities and motives relate to experiential aspects such as entertainment activities. Another important category of motives, which has only recently been described in related work, relates to the self, such as personal growth. Our results indicate that while social VR provides a superior social experience than traditional digital social spaces, like games or social media, users still desire better and affordable tracking technology, increased sensory immersion, and further improvement concerning social features. These findings complement related work as they come from a comparatively large sample (N= 273) and summarize a general user view on social VR. Besides confirming an intuitive assumption, they help identify use cases and opportunities for further research on social VR.

Research on VR Exergaming is mostly conducted with participants who are not presented a choice whether or not to play the exergame and thus to perform a certain strenuous activity. Whether players would engage in such activity if it were optional and how they could be motivated to do so is mostly neglected. Therefore, we have developed a novel controller and implemented a VR exergame that utilizes Virtual Performance Augmentation (VPA) to motivate players to engage in an optional strenuous activity. The motivational impact of three different conditions (VPA vs. Points vs. No Motivator) was evaluated in a study with 47 participants. Our results suggest that using VPA can significantly increase the time the players engage in the strenuous activity enriched by VPA, while in contrast to our hypotheses, no significant differences for the players' enjoyment and perceived exertion between the conditions were found. We discuss our findings in the context of motivation, exertion, and the resulting implications for further VR exergames research.

We present the concept, design, and evaluation of a playful mobile virtual reality (VR) app for children to reduce anxiety and stress during MRI examinations. The Pengunaut Trainer aims to help children to familiarize themselves with the medical environment so that they can be examined without fear, rendering sedation unnecessary. The young patients learn about the procedure and train to lie still during a virtual MRI scan. We conducted a clinical trial focusing on an in-depth analysis of the game design. 29 children trained over 14 days on average before their MRI examination. The participants were impressed by the VR experience and motivated to train. They reported high levels of immersion and positive affect. Anxiety and negative feelings towards the upcoming MRI examination were significantly reduced after the training period. Moreover, our results indicate that the Pengunaut Trainer could be effective in reducing anxiety and stress during the MRI scan. Our results and the positive feedback from parents and medical professionals prove the validity of our approach.

Virtual Reality (VR) exergaming is a beneficial and promising approach resulting from the combination of physical activity with the high motivation and enjoyment immersive VR offers. However, exergames can often fail to reach suggested levels of exertion. We, therefore, integrated a heavy passive haptic controller into a VR exergame. We explore the impact of the passive haptic controller and different kinds of kinesthetic feedback resulting from different interactions on the player experience. Our results of an extensive study (N=82) suggest, that using a heavy controller can significantly increase the exertion without reducing the motivation in contrast to using an HTC Vive controller. We discuss this finding in the context of haptic feedback and the experience of presence and the resulting implications for further research and VR exergames.

We present user study results on virtual body contact experience in a two-user VR scenario, in which participants performed different touches with a research assistant. The interaction evoked different emotional reactions in perceived relaxation, happiness, desire, anxiety, disgust, and fear. Congruent to physical social touch, the evaluation of virtual body contact was modulated by intimacy, touch direction, and sex. Further, individual comfort with interpersonal touch was positively associated with perceived relaxation and happiness. We discuss the results regarding implications for follow-up studies and infer implications for the use of social touch in social VR applications.

Our research investigates the role of physical co-presence for the experience of multiplayer cooperation in virtual reality (VR). We developed and compared a shared-room (co-located) and separated-room (remote) version of a cooperative two-player VR game. In an extensive study (N=92) we assessed measures of task awareness and spatial presence, as well as player communication, interaction, and performance. Our results indicate that players sharing the same physical space tend to neglect the cooperative task. Moreover, our results indicate that being physically separated can beneficially impact the perceived cooperative social presence, quality of communication, and performance in contrast to sharing a physical space. The role of physical co-location in room-scale VR and potential confounding effects caused by it, as well as implications for further research, are discussed.

This paper presents the ongoing work on a technological pipeline to automate the recording and analysis of player speech data in the evaluation of player experience. The pipeline generates a heatmap that visualizes where the players in the virtual environment have made positive, negative, and neutral statements. Moreover, the heatmap provides spatiotemporal information of in-game events, as well as interactive features like filters and modifiers. We describe how the pipeline is set up for the Unity game engine, how we implemented the sentiment classification module as well as the visualization of the tracked data. Concluding, we define goals for further development.

The presence of observers and virtual characters can significantly shape our gaming experience. Researchers suppose that most of the basic socio-psychological phenomena are also applicable for digital games. However, the social processes in gaming setups can differ from our experience in other social situations. Our work emphasizes that awareness. Insights are needed for the purposeful design of a game's social setting, specifically in applied contexts of learning and training. Here, we focus on the social facilitation effect, which describes an unconscious change in performance due to the presence of others, by investigating the impact of real observers and virtual agents on player experience and performance in four different games. The results of our four studies show that, in contrast to previous assumptions, in-game success was not significantly influenced by the presence of any social entity, indicating that social facilitation does not generally apply to the context of playing digital games.

Many people, especially children, perceive MRI exams as threatening. They experience anxiety and stress during the procedure. Often this results in premature termination of the scan or low image quality. To avoid these adverse effects, it is common to sedate anxious patients. We present a playful virtual reality (VR) application for children (8 - 15 years) to counter anxiety and avoid sedation. Our approach uses a realistic virtual MRI scanner for desensitization and habituation to the MRI exam. To compensate the limited amount of profound knowledge about the design of child-tailored VR applications, we pursued a child-centered design process. Starting with expert interviews, we iterated through several development cycles and carried out focus group testings to evaluate prototypes of the VR application. Then, we conducted a field study with 13 patients under real life clinical conditions. Although results were non-significant, tendencies indicate a drop in the anxiety level after using the application. Furthermore, the application received strong support of the participating children, and medical professionals.

Virtual reality games have repeatedly been criticized as being isolating or "anti-social" due to the necessity of covering the player's perception and cognition from the real world in order to allow diving into the game world. Therefore, we investigate approaches to enhance the sociability of VR games by integrating social entities. In a comprehensive study with 75 participants using a testbed game, we compared the impact of a co-player and a virtual agent on virtual reality player experience in terms of enjoyment, perceived loneliness, social presence, and immersion. Results indicate that social entities decrease the perception of loneliness in VR and that their influence on player experience is moderated by their degree of agency and interactivity. Moreover, we found that social entities do not necessarily enhance enjoyment in VR games compared to a single player mode, but can instead also interfere with positive experiences. We conclude that adding a social component to a VR game can enhance player experience by reducing loneliness but requires close consideration to the design and implementation of both social interaction mechanics and the social entity itself.

This paper explores the potential and applicability of gameplay metrics to assess social behavior and interactions of players. As digital games are often played in social contexts, social phenomena and processes are an important part of game user research and supposed to have significant impact on the overall player experience. Gameplay metrics have been used as one method to measure player behavior, but have not been applied to detect social aspects of play yet. We present the conceptualization, application, and evaluation of three social gameplay metrics that aim at measuring social presence, cooperation, and leadership, respectively. A comparison of the metrics' data with scores of self-report measures addressing the same concepts shows high positive correlations, thus indicating reliability of the metrics.

The outstanding characteristic of virtual reality (VR) games is the ability to immerse the player into the game world and to support a natural experience. Reality offers a high degree of freedom in moving around, which is accordingly expected by players in the virtual environment. This freedom of player navigation challenges designers of open VR worlds. Players might get lost, get bored, or unintendedly reach the world's limits, which all can break immersion and result in negative player experiences. We identify typical navigational problems in first person VR games and present design patterns to guide players without restricting freedom and immersion. As an initial step towards empirically validated design recommendations, we conducted a study with 88 participants to evaluate the most common design patterns by analyzing player behavior in experimental settings. Our results confirm both the validity of our approach and methodology, and the practical implication of the presented patterns.

The paper presents a work-in-progress report on a long-term project to create a game-based prevention program against performance anxiety (PA) in primary schools. The approach described reflects the special requirements of children and teachers within the context on a didactical, organizational and conceptual level as well as those of a low cost development with student teams. A study on the first game prototype conducted among 61 pupil showed positive results in learning and insights on the situated context and further design and development. The general concept of a situated multimedia approach with didactically framed interactive game-components seems correct.

New technologies have made the mobile phone to a multifunctional ally who accompanies many people in their everyday life. Smartphones and tablet PCs have also established new game settings. In this paper, we investigate a new trend utilizing smart devices as second screens that are added to gaming situations. We give a definition of Second Screen Gaming, and illuminate a special subcategory we call Smart Gaming. Further, we argue that there is a need for comprehensive design guidelines to integrate the second screen as a core part of the game design. Additionally, we have identified several challenges while designing such games and point out the opportunities for game designers in following this new trend. At the end of this work, three game prototypes are introduced as case studies, which demonstrate different aspects of Second Screen Gaming and thereby illustrate how innovative, engaging and highly social games can be created.

We explore the potential of stereoscopic 3D (S3D) vision in offering distinct gameplay using an S3D-specific game called Deepress3D. Our game utilizes established S3D design principles for optimizing GUI design, visual comfort and game mechanics which rely on depth perception in time-pressured spatial conflicts. The game collects detailed S3D player metrics and allows players to choose between different, evenly matched strategies. We conducted a between subjects study comparing S3D and monoscopic versions of Deepress3D that examined player behavior and performance and measured user-reported data on presence, simulator sickness, and game experience. Confirming previous results, stereo users reported higher spatial presence. More importantly, for the first time, our game metrics indicate that S3D vision can measurably change player behavior depending on actual game content and level design, without necessarily affecting performance or emotional experience. These findings indicate the potential for optimizing applications for stereo users distinguishing them as a distinct group in HCI research.

Creating graphical user interfaces (GUI) for stereoscopic 3D (S3D) games is a difficult choice between visual comfort and effect. We present a S3D Game GUI Design Space and a list of S3D-specific attributes that emphasizes integrating visually comfortable interfaces into the game world, story and S3D view. To showcase our approach, we created two GUI concepts and evaluated them with 32 users. Our results show quality improvements for a combination of bottom position and visual attachment for a menu. In a referencing interface, placing the reference near to the target depth significantly improved perceived quality, game integration, and increased presence. These results confirm the need to create S3D GUIs with perceptual constraints in mind, demonstrating the potential to extend the user experience. Additionally, our design space offers a formal and flexible way to create new effects in S3D GUIs.

Recent advances in digital game technology are making stereoscopic games more popular. Stereoscopic 3D graphics promise a better gaming experience but this potential has not yet been proven empirically. In this paper, we present a comprehensive study that evaluates player experience of three stereoscopic games in comparison with their monoscopic counterparts. We examined 60 participants, each playing one of the three games, using three self-reporting questionnaires and one psychophysiological instrument. Our main results are (1) stereoscopy in games increased experienced immersion, spatial presence, and simulator sickness; (2) the effects strongly differed across the three games and for both genders, indicating more affect on male users and with games involving depth animations; (3) results related to attention and cognitive involvement indicate more direct and less thoughtful interactions with stereoscopic games, pointing towards a more natural experience through stereoscopy.

Multi-pass stereoscopic video rendering (MSVR) allows to present stereoscopic video streams within game engines on consumer graphics boards. We present our approach and discuss aspects of performance and occlusion of virtual objects.

We propose a course design that fits a practical game development project into a regular game design lecture course. As this approach requires a consistent structure, our concept proposes an adaption of Scrum that is based on the game development life-cycle: ABC-Sprints consist of three Sprints to iteratively create Alpha, Beta and Completed versions of a game. We present a detailed walkthrough of the course and give results of a formal evaluation. These indicate that ABC-Sprints help students to manage their workload and to increase productivity over time. Consequently, three teams each presented a game at the end of the course that technically exceeded typical outcomes of game projects without lectures. We hence encourage to apply ABC-Sprints to other curricula and provide a set of recommendations.

This paper proposes a game authoring tool especially designed for children that concentrates: 1) flexibility of interaction and game construction activity for children, and 2) the possible implementation of the tool for children to learn programming in schools.

Most illustrative techniques used in non-photorealistic rendering to date apply a rendering style to objects or a scene and alter the appearance of this style by employing illumination or depth cueing. However for generating high quality illustrations this approach relies almost entirely on smart placement of light sources. We introduce the concept of illustrative effects to describe the workings of illustrative techniques that rely on spatial location rather than just illumination or depth. Although the rendering style is still object-dependent, this technique allows us to visualize or emphasize parts of objects or the whole scene without being limited by the scene's object decomposition. The approach also enforces the decoupling of the model and its animation from the visualization task. We demonstrate our approach using a sample collection of illustrative effects applied to line drawings. A uniform set of tools to manipulate these effects is provided.

One of the assumptions of current software for visualizing architecture is that the underlying geometry is a correct, objective and complete representation of the objects in question. However, we argue that such an ideal situation can hardly be met. Instead, there are a variety of situations in which there is considerable uncertainty associated with some features of a model. Furthermore, the model usally stems from design decisions which are not encoded in the model but which may be important for users. We argue that more information about geometric models should be representable and visualizable. In particular, we propose non-photorealistic rendering styles for encoding such additional information in a visualization of a 3D model which goes over and above the geometry. We then apply this concept to visualizations of virtual reconstructions of ancient architecture. Finally, we describe the prototypical system AncientVis, which represents an approach to visualizing models with uncertain features.

Presents a visualisation of a medieval palace as an application for a new rendering and animation tool which is capable of rendering images in the style of line drawings. In contrast to other systems, we are able to generate frame-to-frame coherent line drawings in order to render an animation. The application of this presentation illustrates the capabilities of animated line drawings and makes use of different drawing techniques, such as simplifying a scene and emphasising important objects.