Investigating Object Translation in Room-scale, Handheld Virtual Reality.

Handheld devices have become an inclusive alternative to head-mounted displays in virtual reality (VR) environments, enhancing accessibility and allowing cross-device collaboration. Object manipulation techniques in 3D space with handheld devices, such as those in handheld augmented reality (AR), have been typically evaluated in table-top scale and we currently lack an understanding of how these techniques perform in larger scale environments. We conducted two studies, each with 30 participants, to investigate how different techniques impact usability and performance for room-scale handheld VR object translations. We compared three translation techniques that are similar to commonly studied techniques in handheld AR: 3DSlide, VirtualGrasp, and Joystick. We also examined the effects of target size, target distance, and user mobility conditions (stationary vs. moving). Results indicated that the Joystick technique, which allowed translation in relation to the user's perspective, was the fastest and most preferred, without difference in precision. Our findings provide insights for designing room-scale handheld VR systems, with potential implications for mixed reality systems involving handheld devices.

Investigating Professional Analyst Strategies in Immersive Space to Think.

Existing research on sensemaking in immersive analytics systems primarily focuses on understanding how users complete analysis within these systems with quantitative and qualitative datasets. However, these user studies mainly concentrate on understanding analysis styles and methodologies from a predominantly novice user study population. While this approach provides excellent initial insights into what users may do within IA systems, it fails to address how professionals may utilize an immersive analytic system for analysis tasks. In our work, we build upon an existing immersive analytics concept - "Immersive Space to Think" to understand how professional user populations differ from novice users in immersive analytic system usage. We conducted a user study with 11 professional intelligence analysts who completed three analysis sessions each. Using our results from this study, we provide deep analysis into how professional users complete sensemaking within immersive analytic systems, compare our findings to previously published findings with a novice user population, and provide insights into how to develop better IA systems to support the professional analyst's strategies within these systems.

Multiple Monitors or Single Canvas? Evaluating Window Management and Layout Strategies on Virtual Displays.

Virtual displays enabled through head-worn augmented reality have unique characteristics that can yield extensive amounts of screen space. Existing research has shown that increasing the space on a computer screen can enhance usability. Since virtual displays offer the unique ability to present content without rigid physical space constraints, they provide various new design possibilities. Therefore, we must understand the trade-offs of layout choices when structuring that space. We propose a single Canvas approach that eliminates boundaries from traditional multi-monitor approaches and instead places windows in one large, unified space. Our user study compared this approach against a multi-monitor setup, and we considered both purely virtual systems and hybrid systems that included a physical monitor. We looked into usability factors such as performance, accuracy, and overall window management. Results show that Canvas displays can cause users to compact window layouts more than multiple monitors with snapping behavior, even though such optimizations may not lead to longer window management times. We did not find conclusive evidence of either setup providing a better user experience. Multi-Monitor displays offer quick window management with snapping and a structured layout through subdivisions. However, Canvas displays allow for more control in placement and size, lowering the amount of space used and, thus, head rotation. Multi-Monitor benefits were more prominent in the hybrid configuration, while the Canvas display was more beneficial in the purely virtual configuration.

Gestures vs. Emojis: Comparing Non-Verbal Reaction Visualizations for Immersive Collaboration.

Collaborative virtual environments afford new capabilities in telepresence applications, allowing participants to co-inhabit an environment to interact while being embodied via avatars. However, shared content within these environments often takes away the attention of collaborators from observing the non-verbal cues conveyed by their peers, resulting in less effective communication. Exaggerated gestures, abstract visuals, as well as a combination of the two, have the potential to improve the effectiveness of communication within these environments in comparison to familiar, natural non-verbal visualizations. We designed and conducted a user study where we evaluated the impact of these different non-verbal visualizations on users' identification time, understanding, and perception. We found that exaggerated gestures generally perform better than non-exaggerated gestures, abstract visuals are an effective means to convey intentional reactions, and the combination of gestures with abstract visuals provides some benefits compared to their standalone counterparts.

Exploring the Evolution of Sensemaking Strategies in Immersive Space to Think.

Existing research on immersive analytics to support the sensemaking process focuses on single-session sensemaking tasks. However, in the wild, sensemaking can take days or months to complete. In order to understand the full benefits of immersive analytic systems, we need to understand how immersive analytic systems provide flexibility for the dynamic nature of the sensemaking process. In our work, we build upon an existing immersive analytic system - Immersive Space to Think, to evaluate how immersive analytic systems can support sensemaking tasks over time. We conducted a user study with eight participants with three separate analysis sessions each. We found significant differences between analysis strategies between sessions one, two, and three, which suggest that immersive space to think can benefit analysts during multiple stages in the sensemaking process.

Evaluation of Pointing Ray Techniques for Distant Object Referencing in Model-Free Outdoor Collaborative Augmented Reality.

Referencing objects of interest is a common requirement in many collaborative tasks. Nonetheless, accurate object referencing at a distance can be challenging due to the reduced visibility of the objects or the collaborator and limited communication medium. Augmented Reality (AR) may help address the issues by providing virtual pointing rays to the target of common interest. However, such pointing ray techniques can face critical limitations in large outdoor spaces, especially when the environment model is unavailable. In this work, we evaluated two pointing ray techniques for distant object referencing in model-free AR from the literature: the Double Ray technique enhancing visual matching between rays and targets, and the Parallel Bars technique providing artificial orientation cues. Our experiment in outdoor AR involving participants as pointers and observers partially replicated results from a previous study that only evaluated observers in simulated AR. We found that while the effectiveness of the Double Ray technique is reduced with the additional workload for the pointer and human pointing errors, it is still beneficial for distant object referencing.

Virtual Replicas of Real Places: Experimental Investigations.

As virtual reality (VR) technology becomes cheaper, higher-quality, and more widely available, it is seeing increasing use in a variety of applications including cultural heritage, real estate, and architecture. A common goal for all these applications is a compelling virtual recreation of a real place. Despite this, there has been very little research into how users perceive and experience such replicated spaces. This article reports the results from a series of three user studies investigating this topic. Results include that the scale of the room and large objects in it are most important for users to perceive the room as real and that non-physical behaviors such as objects floating in air are readily noticeable and have a negative effect even when the errors are small in scale.

Pseudo-Haptic Display of Mass and Mass Distribution During Object Rotation in Virtual Reality.

We propose and evaluate novel pseudo-haptic techniques to display mass and mass distribution for proxy-based object manipulation in virtual reality. These techniques are specifically designed to generate haptic effects during the object's rotation. They rely on manipulating the mapping between visual cues of motion and kinesthetic cues of force to generate a sense of heaviness, which alters the perception of the object's mass-related properties without changing the physical proxy. First we present a technique to display an object's mass by scaling its rotational motion relative to its mass. A psycho-physical experiment demonstrates that this technique effectively generates correct perceptions of relative mass between two virtual objects. We then present two pseudo-haptic techniques designed to display an object's mass distribution. One of them relies on manipulating the pivot point of rotation, while the other adjusts rotational motion based on the real-time dynamics of the moving object. An empirical study shows that both techniques can influence perception of mass distribution, with the second technique being significantly more effective.

Immersive Analytics: Theory and Research Agenda.

Advances in a variety of computing fields, including "big data," machine learning, visualization, and augmented/mixed/virtual reality, have combined to give rise to the emerging field of immersive analytics, which investigates how these new technologies support analysis and decision making. Thus far, we feel that immersive analytics research has been somewhat ad hoc, possibly owing to the fact that there is not yet an organizing framework for immersive analytics research. In this paper, we address this lack by proposing a definition for immersive analytics and identifying some general research areas and specific research questions that will be important for the development of this field. We also present three case studies that, while all being examples of what we would consider immersive analytics, present different challenges, and opportunities. These serve to demonstrate the breadth of immersive analytics and illustrate how the framework proposed in this paper applies to practical research.

Amplified Head Rotation in Virtual Reality and the Effects on 3D Search, Training Transfer, and Spatial Orientation.

Many types of virtual reality (VR) systems allow users to use natural, physical head movements to view a 3D environment. In some situations, such as when using systems that lack a fully surrounding display or when opting for convenient low-effort interaction, view control can be enabled through a combination of physical and virtual turns to view the environment, but the reduced realism could potentially interfere with the ability to maintain spatial orientation. One solution to this problem is to amplify head rotations such that smaller physical turns are mapped to larger virtual turns, allowing trainees to view the entire surrounding environment with small head movements. This solution is attractive because it allows semi-natural physical view control rather than requiring complete physical rotations or a fully-surrounding display. However, the effects of amplified head rotations on spatial orientation and many practical tasks are not well understood. In this paper, we present an experiment that evaluates the influence of amplified head rotation on 3D search, spatial orientation, and cybersickness. In the study, we varied the amount of amplification and also varied the type of display used (head-mounted display or surround-screen CAVE) for the VR search task. By evaluating participants first with amplification and then without, we were also able to study training transfer effects. The findings demonstrate the feasibility of using amplified head rotation to view 360 degrees of virtual space, but noticeable problems were identified when using high amplification with a head-mounted display. In addition, participants were able to more easily maintain a sense of spatial orientation when using the CAVE version of the application, which suggests that visibility of the user's body and awareness of the CAVE's physical environment may have contributed to the ability to use the amplification technique while keeping track of orientation.

Effects of Field of View and Visual Complexity on Virtual Reality Training Effectiveness for a Visual Scanning Task.

Virtual reality training systems are commonly used in a variety of domains, and it is important to understand how the realism of a training simulation influences training effectiveness. We conducted a controlled experiment to test the effects of display and scenario properties on training effectiveness for a visual scanning task in a simulated urban environment. The experiment varied the levels of field of view and visual complexity during a training phase and then evaluated scanning performance with the simulator's highest levels of fidelity and scene complexity. To assess scanning performance, we measured target detection and adherence to a prescribed strategy. The results show that both field of view and visual complexity significantly affected target detection during training; higher field of view led to better performance and higher visual complexity worsened performance. Additionally, adherence to the prescribed visual scanning strategy during assessment was best when the level of visual complexity during training matched that of the assessment conditions, providing evidence that similar visual complexity was important for learning the technique. The results also demonstrate that task performance during training was not always a sufficient measure of mastery of an instructed technique. That is, if learning a prescribed strategy or skill is the goal of a training exercise, performance in a simulation may not be an appropriate indicator of effectiveness outside of training-evaluation in a more realistic setting may be necessary.

Effects of VR system fidelity on analyzing isosurface visualization of volume datasets.

Volume visualization is an important technique for analyzing datasets from a variety of different scientific domains. Volume data analysis is inherently difficult because volumes are three-dimensional, dense, and unfamiliar, requiring scientists to precisely control the viewpoint and to make precise spatial judgments. Researchers have proposed that more immersive (higher fidelity) VR systems might improve task performance with volume datasets, and significant results tied to different components of display fidelity have been reported. However, more information is needed to generalize these results to different task types, domains, and rendering styles. We visualized isosurfaces extracted from synchrotron microscopic computed tomography (SR-µCT) scans of beetles, in a CAVE-like display. We ran a controlled experiment evaluating the effects of three components of system fidelity (field of regard, stereoscopy, and head tracking) on a variety of abstract task categories that are applicable to various scientific domains, and also compared our results with those from our prior experiment using 3D texture-based rendering. We report many significant findings. For example, for search and spatial judgment tasks with isosurface visualization, a stereoscopic display provides better performance, but for tasks with 3D texture-based rendering, displays with higher field of regard were more effective, independent of the levels of the other display components. We also found that systems with high field of regard and head tracking improve performance in spatial judgment tasks. Our results extend existing knowledge and produce new guidelines for designing VR systems to improve the effectiveness of volume data analysis.

Feasibility of training athletes for high-pressure situations using virtual reality.

Virtual reality (VR) has been successfully applied to a broad range of training domains; however, to date there is little research investigating its benefits for sport psychology training. We hypothesized that using high-fidelity VR systems to display realistic 3D sport environments could trigger anxiety, allowing resilience-training systems to prepare athletes for real-world, highpressure situations. In this work we investigated the feasibility and usefulness of using VR for sport psychology training. We developed a virtual soccer goalkeeping application for the Virginia Tech Visionarium VisCube (a CAVE-like display system), in which users defend against simulated penalty kicks using their own bodies. Using the application, we ran a controlled, within-subjects experiment with three independent variables: known anxiety triggers, field of regard, and simulation fidelity. The results demonstrate that a VR sport-oriented system can induce increased anxiety (physiological and subjective measures) compared to a baseline condition. There were a number of main effects and interaction effects for all three independent variables in terms of the subjective measures of anxiety. Both known anxiety triggers and simulation fidelity had a direct relationship to anxiety, while field of regard had an inverse relationship. Overall, the results demonstrate great potential for VR sport psychology training systems; however, further research is needed to determine if training in a VR environment can lead to long-term reduction in sport-induced anxiety.

Validation of the MR simulation approach for evaluating the effects of immersion on visual analysis of volume data.

In our research agenda to study the effects of immersion (level of fidelity) on various tasks in virtual reality (VR) systems, we have found that the most generalizable findings come not from direct comparisons of different technologies, but from controlled simulations of those technologies. We call this the mixed reality (MR) simulation approach. However, the validity of MR simulation, especially when different simulator platforms are used, can be questioned. In this paper, we report the results of an experiment examining the effects of field of regard (FOR) and head tracking on the analysis of volume visualized micro-CT datasets, and compare them with those from a previous study. The original study used a CAVE-like display as the MR simulator platform, while the present study used a high-end head-mounted display (HMD). Out of the 24 combinations of system characteristics and tasks tested on the two platforms, we found that the results produced by the two different MR simulators were similar in 20 cases. However, only one of the significant effects found in the original experiment for quantitative tasks was reproduced in the present study. Our observations provide evidence both for and against the validity of MR simulation, and give insight into the differences caused by different MR simulator platforms. The present experiment also examined new conditions not present in the original study, and produced new significant results, which confirm and extend previous existing knowledge on the effects of FOR and head tracking. We provide design guidelines for choosing display systems that can improve the effectiveness of volume visualization applications.

The effects of visual realism on search tasks in mixed reality simulation.

In this paper, we investigate the validity of Mixed Reality (MR) Simulation by conducting an experiment studying the effects of the visual realism of the simulated environment on various search tasks in Augmented Reality (AR). MR Simulation is a practical approach to conducting controlled and repeatable user experiments in MR, including AR. This approach uses a high-fidelity Virtual Reality (VR) display system to simulate a wide range of equal or lower fidelity displays from the MR continuum, for the express purpose of conducting user experiments. For the experiment, we created three virtual models of a real-world location, each with a different perceived level of visual realism. We designed and executed an AR experiment using the real-world location and repeated the experiment within VR using the three virtual models we created. The experiment looked into how fast users could search for both physical and virtual information that was present in the scene. Our experiment demonstrates the usefulness of MR Simulation and provides early evidence for the validity of MR Simulation with respect to AR search tasks performed in immersive VR.

Studying the effects of stereo, head tracking, and field of regard on a small-scale spatial judgment task.

Spatial judgments are important for many real-world tasks in engineering and scientific visualization. While existing research provides evidence that higher levels of display and interaction fidelity in virtual reality systems offer advantages for spatial understanding, few investigations have focused on small-scale spatial judgments or employed experimental tasks similar to those used in real-world applications. After an earlier study that considered a broad analysis of various spatial understanding tasks, we present the results of a follow-up study focusing on small-scale spatial judgments. In this research, we independently controlled field of regard, stereoscopy, and head-tracked rendering to study their effects on the performance of a task involving precise spatial inspections of complex 3D structures. Measuring time and errors, we asked participants to distinguish between structural gaps and intersections between components of 3D models designed to be similar to real underground cave systems. The overall results suggest that the addition of the higher fidelity system features support performance improvements in making small-scale spatial judgments. Through analyses of the effects of individual system components, the experiment shows that participants made significantly fewer errors with either an increased field of regard or with the addition of head-tracked rendering. The results also indicate that participants performed significantly faster when the system provided the combination of stereo and head-tracked rendering.

Effects of immersion on visual analysis of volume data.

Volume visualization has been widely used for decades for analyzing datasets ranging from 3D medical images to seismic data to paleontological data. Many have proposed using immersive virtual reality (VR) systems to view volume visualizations, and there is anecdotal evidence of the benefits of VR for this purpose. However, there has been very little empirical research exploring the effects of higher levels of immersion for volume visualization, and it is not known how various components of immersion influence the effectiveness of visualization in VR. We conducted a controlled experiment in which we studied the independent and combined effects of three components of immersion (head tracking, field of regard, and stereoscopic rendering) on the effectiveness of visualization tasks with two x-ray microscopic computed tomography datasets. We report significant benefits of analyzing volume data in an environment involving those components of immersion. We find that the benefits do not necessarily require all three components simultaneously, and that the components have variable influence on different task categories. The results of our study improve our understanding of the effects of immersion on perceived and actual task performance, and provide guidance on the choice of display systems to designers seeking to maximize the effectiveness of volume visualization applications.

Evaluating display fidelity and interaction fidelity in a virtual reality game.

In recent years, consumers have witnessed a technological revolution that has delivered more-realistic experiences in their own homes through high-definition, stereoscopic televisions and natural, gesture-based video game consoles. Although these experiences are more realistic, offering higher levels of fidelity, it is not clear how the increased display and interaction aspects of fidelity impact the user experience. Since immersive virtual reality (VR) allows us to achieve very high levels of fidelity, we designed and conducted a study that used a six-sided CAVE to evaluate display fidelity and interaction fidelity independently, at extremely high and low levels, for a VR first-person shooter (FPS) game. Our goal was to gain a better understanding of the effects of fidelity on the user in a complex, performance-intensive context. The results of our study indicate that both display and interaction fidelity significantly affect strategy and performance, as well as subjective judgments of presence, engagement, and usability. In particular, performance results were strongly in favor of two conditions: low-display, low-interaction fidelity (representative of traditional FPS games) and high-display, high-interaction fidelity (similar to the real world).

3D user interfaces: new directions and perspectives.

Three-dimensional user interfaces (3D UIs) let users interact with virtual objects, environments, or information using direct 3D input in the physical and/or virtual space. In this article, the founders and organizers of the IEEE Symposium on 3D User Interfaces reflect on the state of the art in several key aspects of 3D UIs and speculate on future research.

Contextualized videos: combining videos with environment models to support situational understanding.

Multiple spatially-related videos are increasingly used in security, communication, and other applications. Since it can be difficult to understand the spatial relationships between multiple videos in complex environments (e.g. to predict a person's path through a building), some visualization techniques, such as video texture projection, have been used to aid spatial understanding. In this paper, we identify and begin to characterize an overall class of visualization techniques that combine video with 3D spatial context. This set of techniques, which we call contextualized videos, forms a design palette which must be well understood so that designers can select and use appropriate techniques that address the requirements of particular spatial video tasks. In this paper, we first identify user tasks in video surveillance that are likely to benefit from contextualized videos and discuss the video, model, and navigation related dimensions of the contextualized video design space. We then describe our contextualized video testbed which allows us to explore this design space and compose various video visualizations for evaluation. Finally, we describe the results of our process to identify promising design patterns through user selection of visualization features from the design space, followed by user interviews.