An ontology is a structured representation of knowledge that organizes domain-specific concepts and their relationships. As ontologies scale, visualizing and manipulating them using traditional two-dimensional interfaces becomes increasingly challenging due to visual clutter and structural complexity. To address this, we developed a multi-user immersive ontology manipulation system that enables interaction with ontological structures in a three-dimensional space. This work-in-progress study adopts a usability and experience-focused perspective to examine how users navigate, coordinate, and perform ontology-related tasks in a shared immersive setting. We conducted an exploratory user study using qualitative and observational methods, in which participants completed visualization and authoring tasks in co-present, multi-user Virtual Reality (VR). Our analysis focuses on user strategies, interaction patterns, and breakdowns observed during task execution, supported by analysis of audio transcripts. Preliminary findings highlight challenges in spatial orientation, object visibility, and awareness of collaborators, as well as emergent collaborative behaviors, including role adaptation, peer support, and shared task planning. Participants also reported a strong sense of co-presence and engagement in the shared environment. These early results provide insights into the opportunities and limitations of immersive VR for collaborative knowledge work, and inform future directions for interaction design and evaluation in collaborative immersive analytics systems.

Immediate care for trauma wounded patients in austere or remote settings makes medical knowledge, skills, and efficiency of the on-duty medical professional paramount. For wounds that extend deep into internal anatomy, proper visualization of internal anatomy can enable more efficient and effective evaluation when presented to medical providers positioned close to the point of injury (POI). In this paper, a conceptual Augmented Reality (AR) surgical tool is presented to provide visualization of internal human anatomy, superimposed on the view of a patient, to assist medical providers for immediate casualty care. This AR surgical tool can play a role in 3D surgery or treatment planning as a navigational aid in preparing medical interventions and enhancing surgery or treatment procedures by displaying otherwise obscured anatomy and nearby vessels. Critical software and hardware components are integrated to construct a prototype AR system for the portable AR surgical visualization tool. The system uses a Microsoft HoloLens 1 and an Azure Kinect camera for simultaneous body-tracking and anatomy overlay to demonstrate the overall concept. Future extension of this work will aim to create a more accurate and compact prototype system that utilizes HoloLens 2 with an embedded Kinect camera for laboratory and field tests of its use in surgery assistance. Such an AR tool can also serve as a training tool for medical caregivers, applied with a human subject or a medical manikin.

Virtual reality (VR) computer interfaces show promise for improving societal communication and representation of information due to their unique ability to be placed spatially around the user in three-dimensional (3D) space. This opens new possibilities for presentation and user interaction with the target information, and may be especially impactful for the education of science, technology, engineering, and mathematics (STEM) professionals. Simulations and visualizations have been shown in research studies to improve the efficiency of STEM learners compared to the less sensorimotor rich learning mediums of live instruction and textbook reading. Yet, learning science research into immersive computer simulation environments for educational applications remains limited. To address this research gap, we analyzed a fundamental VR interface capability, virtual environmental traversal, and its impact on participants' learning. We altered the traversal ability between two groups of STEM learners within the same virtual environment and compared their performance. Findings point that VR computer interfaces, regardless of environmental traversal, are suitable STEM learning environments, but that environmental traversal can increase learning efficiency.

Recent research has proposed teleoperation of robotic and aerial vehicles using head motion tracked by a head-mounted display (HMD). First-person views of the vehicles are usually captured by onboard cameras and presented to users through the display panels of HMDs. This provides users with a direct, immersive and intuitive interface for viewing and control. However, a typically overlooked factor in such designs is the latency introduced by the vehicle dynamics. As head motion is coupled with visual updates in such applications, visual and control latency always exists between the issue of control commands by head movements and the visual feedback received at the completion of the attitude adjustment. This causes a discrepancy between the intended motion, the vestibular cue and the visual cue and may potentially result in simulator sickness. No research has been conducted on how various levels of visual and control latency introduced by dynamics in robots or aerial vehicles affect users' performance and the degree of simulator sickness elicited. Thus, it is uncertain how much performance is degraded by latency and whether such designs are comfortable from the perspective of users. To address these issues, we studied a prototyped scenario of a head motion controlled quadcopter using an HMD. We present a virtual reality (VR) paradigm to systematically assess the effects of visual and control latency in simulated drone control scenarios.

We present a method for estimating the Motion-to-Photon (End-to-End) latency of head mounted displays (HMDs). The specific HMD evaluated in our study was the Oculus Rift DK2, but the procedure is general. We mounted the HMD on a pendulum to introduce damped sinusoidal motion to the HMD during the pendulum swing. The latency was estimated by calculating the phase shift between the captured signals of the physical motion of the HMD and a motion-dependent gradient stimulus rendered on the display. We used the proposed method to estimate both rotational and translational Motion-to-Photon latencies of the Oculus Rift DK2.

Virtual reality simulations of group social interactions are important for many applications, including the virtual treatment of social phobias, crowd and group simulation, collaborative virtual environments (VEs), and entertainment. In such scenarios, when compared to the real world, audio cues are often impoverished. As a result, users cannot rely on subtle spatial audio-visual cues that guide attention and enable effective social interactions in real-world situations. We explored whether gaze-contingent audio enhancement techniques driven by inferring audio-visual attention in virtual displays could be used to enable effective communication in cluttered audio VEs. In all of our experiments, we hypothesized that visual attention could be used as a tool to modulate the quality and intensity of sounds from multiple sources to efficiently and naturally select spatial sound sources. For this purpose, we built a gaze-contingent display (GCD) that allowed tracking of a user’s gaze in real-time and modifying the volume of the speakers’ voices contingent on the current region of overt attention. We compared six different techniques for sound modulation with a base condition providing no attentional modulation of sound. The techniques were compared in terms of source recognition and preference in a set of user studies. Overall, we observed that users liked the ability to control the sounds with their eyes. They felt that a rapid change in attenuation with attention but not the elimination of competing sounds (partial rather than absolute selection) was most natural. In conclusion, audio GCDs offer potential for simulating rich, natural social, and other interactions in VEs. They should be considered for improving both performance and fidelity in applications related to social behaviour scenarios or when the user needs to work with multiple audio sources of information.

Computer-generated objects presented on a display typically have the same focal distance regardless of the monocular and binocular depth cues used to portray a 3D scene. This is because they are presented on a flat screen display that has a fixed physical location. In a stereoscopic 3D display, accommodation (focus) of the eyes should always be at the distance of the screen for clear vision regardless of the depth portrayed; this fixed accommodation conflicts with vergence eye movements that the user must make to fuse stimuli located off the screen. This is known as accommodation-vergence conflict and is detrimental for user experience of stereoscopic virtual environments (VE), as it can cause visual discomfort and diplopia during use of a stereoscopic display. It is believed that, by artificially simulating focal blur and natural accommodation, it is possible to compensate for the vergence-accommodation conflict and alleviate these symptoms. We hypothesized that it is possible to compensate for conflict with a fixed accommodation cue by adding simulated focal blur according to instantaneous fixation.

The visual field is the area of space that can be seen when an observer fixates a given point. Many visual capabilities vary with position in the visual field and many diseases result in changes in the visual field. With current technology, it is possible to build very complex real-time visual field simulations that employ gaze-contingent displays. Nevertheless, there are still no established techniques to evaluate such systems. We have developed a method to evaluate a system's contingency by employing visual blind spot localization as well as foveal fixation. During the experiment, gaze-contingent and static conditions were compared. There was a strong correlation between predicted results and gaze-contingent trials. This evaluation method can also be used with patient populations and for the evaluation of gaze-contingent display systems, when there is need to evaluate a visual field outside of the foveal region.

Effective management and treatment of glaucoma and other visual diseases depend on early diagnosis. However, early symptoms of glaucoma often go unnoticed until a significant portion of the visual field is lost. The ability to simulate the visual consequences of the disease offers potential benefits for patients and clinical education as well as for public awareness of its signs and symptoms. Experiments using simulated visual field defects could identify changes in behaviour, for example during driving, that one uses to compensate at the early stages of the disease's development. Furthermore, by understanding how visual field defects affect performance of visual tasks, we can help develop new strategies to cope with other devastating diseases such as macular degeneration. A Gaze-Contingent Display (GCD) system was developed to simulate an arbitrary visual field in a virtual environment. The system can estimate real-time gaze direction and eye position in earth-fixed coordinates during relatively large head movement, and thus it can be used in immersive projection based VE systems like the CAVE™. Arbitrary visual fields are simulated via OpenGL and Shading Language capabilities and techniques that are supported by the GPU, thus enabling fast performance in real time. In order to simulate realistic visual defects, the system performs multiple image processing operations including change in acuity, brightness, color, glare and image distortion. The final component of the system simulates different virtual scenes that the participant can navigate through and explore. As a result, this system creates an experimental environment to study the effects of low vision on everyday tasks such as driving and navigation.