Gesture interaction is standard in modern extended reality head-mounted displays, e.g., Microsoft HoloLens 2 and Apple Vision Pro. These gestures come from multiple sources, such as elicitation studies, the application designer, or an expert. However, it is unclear if the source of the gesture affects the memorability of gestures (i.e., level of recall). In a user study, 35 participants used the HoloLens 2 to test three gestures set from different sources: 1) expert-defined, whereby we asked four experts to define gestures; 2) user-defined, whereby each participant defined their gestures; and 3) elicitation-defined, whereby we used gestures proposed by previous work. Our results showed that expert-defined gestures (72.73% recall) were more likely to be remembered than elicitation-defined (59.87% recall) gestures. Further, user-defined gestures (88.75% recall) were the most memorable. These data suggest that the source of gestures has a substantial impact on their memorability.

In Virtual Reality (VR), exploring a large virtual environment is still an open research area, as software-based solutions can be challenging to use or contribute to motion sickness. Past work has used omnidirectional treadmills to emulate natural walking in a small space. Yet, the impact on user performance and experience of the different walking techniques these omnidirectional treadmills utilize is still unclear. This study assessed the effects of WALK-IN-PLACE, used with devices like KAT VR mini, and SLIDING, as used by devices like Cyberith Virtualizer ELITE 2, and compared them to NATURAL WALKING. Using a within-study design methodology, eighteen participants navigated a VR maze. We found that participants completed tasks fastest with NATURAL WALKING while SLIDING provided a balanced compromise between immersion and moderate physical effort, and WALK-IN-PLACE required the highest exertion with lower usability. These findings provide practical insights into performance and user-experience differences among the three VR walking techniques, informing VR-ODT selection for applications such as rehabilitation and training.

This paper compares the wayfinding differences between Virtual Reality Omnidirectional Treadmills (VR-ODT) locomotion techniques. We aim to identify their effect on users’ spatial exploration while navigating VEs. Our results demonstrate that VR-ODT locomotion techniques resulted in frequent stops and reorientation efforts, particularly at critical decision points within the maze. However, we did not identify differences between the techniques analyzed.

This paper presents ThermalPen, a novel device for 3D sketching that utilizes thermal feedback to allow users to feel the materiality of their sketches. The pen lets users draw using six colors and three textures mapped to different temperatures. Our goal is to investigate the influence of thermal feedback on user creativity for 3D sketching. In a user study with 24 participants, we asked them to draw with and without thermal feedback. Our results show that thermal feedback improved user creativity for specific tasks. Qualitative results also indicate an effect on the user experience. Our work contributes to understanding how thermal feedback can increase user satisfaction with 3D sketching and provide insights and directions for future work.

Virtual Reality (VR) applications like OpenBrush offer artists access to 3D sketching tools within the digital 3D virtual space. These 3D sketching tools allow users to “paint” using virtual digital strokes that emulate real-world mark-making. Yet, users paint these strokes through (unimodal) VR controllers. Given that sketching in VR is a relatively nascent field, this paper investigates ways to expand our understanding of sketching in virtual space, taking full advantage of what an immersive digital canvas offers. Through a study conducted with the participation of artists, we identify potential methods for natural multimodal and unimodal interaction techniques in 3D sketching. These methods demonstrate ways to incrementally improve existing interaction techniques and incorporate artistic feedback into the design.

Visual guides help to align strokes and raise accuracy in Virtual Reality (VR) sketching tools. Automatic guides that appear at relevant sketching areas are convenient to have for a seamless sketching with a guide. We explore guides that exploit eye-tracking to render them adaptive to the user’s visual attention. EyeGuide and EyeConGuide cause visual grid fragments to appear spatially close to the user’s intended sketches, based on the information of the user’s eye-gaze direction and the 3D position of the hand. Here we evaluated the techniques in two user studies across simple and complex sketching objectives in VR. The results show that gaze-based guides have a positive effect on sketching accuracy, perceived usability and preference over manual activation in the tested tasks. Our research contributes to integrating gaze-contingent techniques for assistive guides and presents important insights into multimodal design applications in VR.

Modern Virtual Reality (VR) technology has enabled users to experience Real Environment (RE) sports in their homes. For VR table tennis, one of the most popular VR sports, the players have rankings and tournaments and compete for RE awards. Based on this phenomenon, this paper aims to understand the benefits of RE training in improving VR table tennis skills. In a user study with 12 novice table tennis players, we measured their performance in 16 basic skills via a pre- and post-study design using a novel training protocol designed for both RE and VR players. We also asked participants for their insights into the training and to evaluate their experience. Our results show a significant improvement in all measured skills. However, participants identified issues with the technology that caused discomfort. Our findings provide valuable insights for software developers working on VR sports applications, enabling them to create better experiences for VR table tennis players. They can also help developers of VR training applications identify areas for improvement with the current technology.

For introductory programming courses, it is crucial to create formative and summarized grading practices that foster growth mindset in students. We explore one way to reimagine and reorient programming assignment grading towards feedback-oriented encouragement for ongoing and continuous learning. This practice of mastery grading encompasses the following key features: (1) students are provided with a comprehensive list of assignment specifications, (2) evaluation of student work is centered on the attainment of specified criteria, employing a nominal scale to denote whether some or all the requirements are met within the deadline, and (3) multiple opportunities are afforded to demonstrate mastery for each specification, without penalties for initial attempts. We share our implementation conducted within an undergraduate first-year web development course, intending it to serve as both a reference and a valuable resource for instructors interested in integrating mastery grading into their own courses.

To understand current practice and explore the potential for more comprehensive evaluations of 3D immersive sketching, drawing, and painting, we present a survey of evaluation methodologies used in existing 3D sketching research, a breakdown and discussion of important phases (sub-tasks) in the 3D sketching process, and a framework that suggests how these factors can inform evaluation strategies in future 3D sketching research. Existing evaluations identified in the survey are organized and discussed within three high-level categories: 1) evaluating the 3D sketching activity, 2) evaluating 3D sketching tools, and 3) evaluating 3D sketching artifacts. The new framework suggests targeting evaluations to one or more of these categories and identifying relevant user populations. In addition, building upon the discussion of the different phases of the 3D sketching process, the framework suggests to evaluate relevant sketching tasks, which may range from low-level perception and hand movements to high-level conceptual design. Finally, we discuss limitations and challenges that arise when evaluating 3D sketching, including a lack of standardization of evaluation methods and multiple, potentially conflicting, ways to evaluate the same task and user interface usability; we also identify opportunities for more holistic evaluations. We hope the results can contribute to accelerating research in this domain and, ultimately, broad adoption of immersive sketching systems.

The Human-computer Interaction (HCI) community has the opportunity to foster the integration of research practices across the Global South and North to begin overcoming colonial relationships. In this paper, we focus on the case of Latin America (LATAM), where initiatives to increase the representation of HCI practitioners lack a consolidated understanding of the practices they employ, the factors that influence them, and the challenges that practitioners face. To address this knowledge gap, we employ a mixed-methods approach, comprising a survey (66 respondents) and in-depth interviews (19 interviewees). Our analyses characterize a set of research perspectives on how HCI is practiced in/about LATAM; a set of driving forces and tensions with a heavy reliance on diasporic dynamics; and a set of professional demands and associated structural limitations. We also offer a roadmap towards building connections across HCI communities, in an attempt to rebuild HCI as a pluriverse.

When working in Virtual Reality (VR), the user’s performance is affected by how the user holds the input device (e.g., controller), typically using either a precision or a power grip. Previous work examined these grip styles for 3D pointing at targets at different depths in peripersonal space and found that participants had a lower error rate with the precision grip but identified no difference in movement speed, throughput, or interaction with target depth. Yet, this previous experiment was potentially affected by tracking differences between devices. This paper reports an experiment that partially replicates and extends the previous study by evaluating the effect of grip style on the 3D selection of nearby targets with the same device. Furthermore, our experiment re-investigates the effect of the vergence-accommodation conflict (VAC) present in current stereo displays on 3D pointing in peripersonal space. Our results show that grip style significantly affects user performance. We hope that our results are useful for researchers and designers when creating virtual environments.

State-of-the-art Virtual Reality (VR) and Augmented Reality (AR) headsets rely on singlefocal stereo displays. For objects away from the focal plane, such displays create a vergence-accommodation conflict (VAC), potentially degrading user interaction performance. In this paper, we study how the VAC affects pointing at targets within arm's reach with virtual hand and raycasting interaction in current stereo display systems. We use a previously proposed experimental methodology that extends the ISO 9241–411:2015 multi-directional selection task to enable fair comparisons between selecting targets in different display conditions. We conducted a user study with eighteen participants and the results indicate that participants were faster and had higher throughput in the constant VAC condition with the virtual hand. We hope that our results enable designers to choose more efficient interaction methods in virtual environments.

The vergence-accommodation conflict (VAC) limits user performance in current Virtual Reality (VR) systems. In this paper, we investigate the effects of the VAC in a single-focal VR system using three experimental conditions: with no VAC, with a constant VAC, and with a varying VAC. Previous work in this area had yielded conflicting results, so we decided to re-investigate this issue. Eighteen participants performed an ISO 9241:411 task in a study that closely replicates previous work, except that the angle of the task space was rotated 20 degrees downward, to make the task less fatiguing to perform, which addresses a potential confound in previous work. We found that the varying VAC condition had worse performance than the other conditions, which indicates that the contrasting results in previous work were very likely due to biomechanical factors. We hope that our work contributes to the understanding of the influence of the VAC in VR systems and potential strategies for improving user experience and performance in immersive virtual environments.

People with color vision deficiency (CVD) often encounter color-related challenges in their daily life, which are difficult for those with non-CVD to comprehend fully. Therefore, we designed a Virtual Reality (VR) serious game, BlueVR , to simulate challenging scenarios encountered by people with CVD and facilitate understanding from people with non-CVD. We conducted an empirical study with thirty participants with non-CVD and six participants with CVD to evaluate the opportunities and challenges of BlueVR . Our findings suggest that BlueVR increased people with non-CVD’s understanding, awareness, and perspective-taking abilities towards people with CVD. Moreover, interviews with participants with CVD revealed that BlueVR accurately depicts their real-life discomforts and meets their expectations to improve potential social awareness. This research contributes valuable insights into the mechanisms underlying the effectiveness of VR serious games in promoting understanding and design implications for future game development.

Previous work hypothesized that for Virtual Reality (VR) and Augmented Reality (AR) displays a mismatch between disparities and optical focus cues, known as the vergence and accommodation conflict (VAC), affects depth perception and thus limits user performance in 3D selection tasks within arm’s reach (peri-personal space). To investigate this question, we built a multifocal stereo display, which can eliminate the influence of the VAC for pointing within the investigated distances. In a user study, participants performed a virtual hand 3D selection task with targets arranged laterally or along the line of sight, with and without a change in visual depth, in display conditions with and without the VAC. Our results show that the VAC influences 3D selection performance in common VR and AR stereo displays and that multifocal displays have a positive effect on 3D selection performance with a virtual hand.

Previous work has shown that the mismatch between disparity and optical focus cues, i.e., the vergence and accommodation conflict (VAC), affects virtual hand selection in immersive systems. To investigate if the VAC also affects distal pointing with ray casting, we ran a user study with an ISO 9241:411 multidirectional selection task where participants selected 3D targets with three different VAC conditions, no VAC, i.e., targets placed roughly at 75 cm, which matches the focal plane of the VR headset, constant VAC, i.e., at 400 cm from the user, and varying VAC, where the depth distance of targets changed between 75 cm and 400 cm. According to our results, the varying VAC condition requires the most time and decreases the throughput performance of the participants. It also takes longer for users to select targets in the constant VAC condition than without the VAC. Our results show that in distal pointing placing objects at different depth planes has detrimental effect on the user performance.

The 2021 VGTC Virtual Reality Best Dissertation Award goes to Mayra Donaji Barrera Machuca, a 2019 graduate from Simon Fraser University, for her dissertation entitled, “Towards More Accurate Immersive 3D Sketching.”. The 2021 VGTC Virtual Reality Best Dissertation Honorable Mention goes to Javad Fotouhi. Dissertation Title: Augmented reality and artificial intelligence in image-guided and robot-assisted interventions.

Accurate sketching in virtual 3D environments is challenging due to aspects like limited depth perception or the absence of physical support. To address this issue, we propose VRSketchPen – a pen that uses two haptic modalities to support virtual sketching without constraining user actions: (1) pneumatic force feedback to simulate the contact pressure of the pen against virtual surfaces and (2) vibrotactile feedback to mimic textures while moving the pen over virtual surfaces. To evaluate VRSketchPen, we conducted a lab experiment with 20 participants to compare (1) pneumatic, (2) vibrotactile and (3) a combination of both with (4) snapping and no assistance for flat and curved surfaces in a 3D virtual environment. Our findings show that usage of pneumatic, vibrotactile and their combination significantly improves 2D shape accuracy and leads to diminished depth errors for flat and curved surfaces. Qualitative results indicate that users find the addition of unconstraining haptic feedback to significantly improve convenience, confidence and user experience.

Virtual Reality (VR) headsets have made immersive 3D drawing available to the general public. However, compared to 2D drawing, the presence of an additional dimension makes sketching in VR challenging, since creating precise strokes that are positioned as intended in all three dimensions imposes higher demands on the users' perception, motor and spatial skills. Another challenge users face is creating accurate shapes in which strokes are positioned correctly relative to previous ones, as they may need to use different views to plan their next hand movement. In this paper, we analyze the behaviours of users with different spatial abilities while drawing in VR. Our results indicate that there are different types of behaviours that affect different aspects of the sketches. We also found that the user's spatial ability affects the shape of the drawing, but not the line precision. Finally, we give recommendations for designing 3D drawing interfaces.

The limitations of stereo display systems affect depth perception, e.g., due to the vergence-accommodation conflict or diplopia. We performed three studies to understand how stereo display deficiencies impact 3D pointing for targets in front of a screen and close to the user, i.e., in peripersonal space. Our first two experiments compare movements with and without a change in visual depth for virtual respectively physical targets. Results indicate that selecting targets along the depth axis is slower and has less throughput for virtual targets, while physical pointing demonstrates the opposite result. We then propose a new 3D extension for Fitts' law that models the effect of stereo display deficiencies. Next, our third experiment verifies the model and measures more broadly how the change in visual depth between targets affects pointing performance in peripersonal space and confirms significant effects on time and throughput. Finally, we discuss implications for 3D user interface design.

Most AR and VR headsets use stereoscopic displays to show virtual objects in 3D. However, the limitations of current stereo display systems affect depth perception through conflicting depth cues, which then also affect virtual hand interaction in peri-personal space, i.e., within arm's reach. We performed a Fitts' law experiment to better understand the impact of stereo display deficiencies of AR and VR headsets on pointing at close-by targets arranged laterally or along the line of sight. According to our results, the movement direction and the corresponding change in target depth affect pointing time and throughput; subjects' movements towards/away from their head were slower and less accurate than their lateral movements (left/right). However, even though subjects moved faster in AR, we did not observe a significant difference for pointing performance between AR and VR headsets, which means that previously identified differences in depth perception between these platforms seem to have no strong effect on interaction. Our results also help 3D user interface designers understand how changes in target depth affect users' performance in different movement directions in AR and VR.

Most current commercial Virtual Reality (VR) drawing applications for creativity rely on freehand 3D drawing as their main interaction paradigm. However, the presence of the additional third dimension makes accurate freehand drawing challenging. Some systems address this problem by constraining or beautifying user strokes, which can be intrusive and can limit the expressivity of freehand drawing. In this paper, we evaluate the effectiveness of relying solely on visual guidance to increase overall drawing shape-likeness. We identified a set of common mistakes that users make while creating freehand strokes in VR and then designed a set of visual guides, the Smart3DGuides, which help users avoid these mistakes. We evaluated Smart3DGuides in two user studies, and our results show that non-constraining visual guides help users draw more accurately.

Constrained interaction and navigation methods for virtual reality reduce the complexity of the interaction. Yet, with previously presented solutions, users need to learn new interaction tools or remember different actions for changing between different interaction methods. In this paper, we propose Fluid VR, a new 3D user interface for interactive virtual environments that lets users seamlessly transition between navigation and selection. Based on the selected object's properties, Fluid VR applies specific constraints to the interaction or navigation associated with the object. This way users have a better control of their actions, without having to change tools or activate different modes of interaction.