VR HMD Research Articles

Integrating eye rotation and contrast sensitivity into image quality evaluation of virtual reality head-mounted displays.

Visual perception on virtual reality head-mounted displays (VR HMDs) involves human vision in the imaging pipeline. Image quality evaluation of VR HMDs may need to be expanded from optical bench testing by incorporating human visual perception. In this study, we implement a 5-degree-of-freedom (5DoF) experimental setup that simulates the human eye geometry and rotation mechanism. Optical modulation transfer function (MTF) measurements are performed using various camera rotation configurations namely pupil rotation, eye rotation, and eye rotation with angle kappa of the human visual system. The measured MTFs of the VR HMD are inserted into a human eye contrast sensitivity model to predict the perceptual contrast sensitivity function (CSF) on a VR HMD. At the same time, we develop a WebXR test platform to perform human observer experiments. Monocular CSFs of human subjects with different interpupillary distance (IPD) are extracted and compared with those calculated from optical MTF measurements. The result shows that image quality, measured as MTF and CSF, degrades at the periphery of display field of view, especially for subjects with an IPD different than that of the HMD. We observed that both the shift of visual point on the HMD eyepiece and the angle between the optical axes of the eye and eyepiece degrade image quality due to optical aberration. The computed CSFs from optical measurement correlates with those of the human observer experiment, with the optimal correlation achieved using the eye rotation with angle kappa setup. The finding demonstrates that more precise image quality assessment can be achieved by integrating eye rotation and human eye contrast sensitivity into optical bench testing.

P‐49: Angular Dependent Point Spread Function Analysis for Virtual Reality Head Mounted Displays

We demonstrate a point spread function method for measuring the angular dependence of the spatial resolution of a virtual reality head mounted display. The angular dependence of spatial resolution of the imaging detector was characterized to remove the detector's contribution at each angular location measured on the VR HMD. This method allows measuring the twodimensional spatial resolution and modulation transfer function.

Omnidirectional Virtual Visual Acuity: A User-Centric Visual Clarity Metric for Virtual Reality Head-Mounted Displays and Environments.

Users' perceived image quality of virtual reality head-mounted displays (VR HMDs) is determined by multiple factors, including the HMD's structure, optical system, display and render resolution, and users' visual acuity (VA). Existing metrics such as pixels per degree (PPD) have limitations that prevent accurate comparison of different VR HMDs. One of the main limitations is that not all VR HMD manufacturers released the official PPD or details of their HMDs' optical systems. Without these details, developers and users cannot know the precise PPD or calculate it for a given HMD. The other issue is that the visual clarity varies with the VR environment. Our work has identified a gap in having a feasible metric that can measure the visual clarity of VR HMDs. To address this gap, we present an end-to-end and user-centric visual clarity metric, omnidirectional virtual visual acuity (OVVA), for VR HMDs. OVVA extends the physical visual acuity chart into a virtual format to measure the virtual visual acuity of an HMD's central focal area and its degradation in its noncentral area. OVVA provides a new perspective to measure visual clarity and can serve as an intuitive and accurate reference for VR applications sensitive to visual accuracy. Our results show that OVVA is a simple yet effective metric for comparing VR HMDs and environments.

UbiSurface: A Robotic Touch Surface for Supporting Mid-air Planar Interactions in Room-Scale VR

Room-scale VR has been considered an alternative to physical office workspaces. For office activities, users frequently require planar input methods, such as typing or handwriting, to quickly record annotations to virtual content. However, current off-the-shelf VR HMD setups rely on mid-air interactions, which can cause arm fatigue and decrease input accuracy. To address this issue, we propose UbiSurface, a robotic touch surface that can automatically reposition itself to physically present a virtual planar input surface (VR whiteboard, VR canvas, etc.) to users and to permit them to achieve accurate and fatigue-less input while walking around a virtual room. We design and implement a prototype of UbiSurface that can dynamically change a canvas-sized touch surface's position, height, and pitch and yaw angles to adapt to virtual surfaces spatially arranged at various locations and angles around a virtual room. We then conduct studies to validate its technical performance and examine how UbiSurface facilitates the user's primary mid-air planar interactions, such as painting and writing in a room-scale VR setup. Our results indicate that this system reduces arm fatigue and increases input accuracy, especially for writing tasks. We then discuss the potential benefits and challenges of robotic touch devices for future room-scale VR setups.

Is embodied interaction beneficial? A study on navigating network visualizations

Network visualizations are commonly used to analyze relationships in various contexts, such as social, biological, and geographical interactions. To efficiently explore a network visualization, the user needs to quickly navigate to different parts of the network and analyze local details. Recent advancements in display and interaction technologies inspire new visions for improved visualization and interaction design. Past research into network design has identified some key benefits to visualizing networks in 3D versus 2D. However, little work has been done to study the impact of varying levels of embodied interaction on network analysis. We present a controlled user study that compared four network visualization environments featuring conditions and hardware that leveraged different amounts of embodiment and visual perception ranging from a 2D visualization desktop environment with a standard mouse to a 3D visualization virtual reality environment. We measured the accuracy, speed, perceived workload, and preferences of 20 participants as they completed three network analytic tasks, each of which required unique navigation and substantial effort to complete. For the task that required participants to iterate over the entire visualization rather than focus on a specific area, we found that participants were more accurate using a VR HMD and a trackball mouse than conventional desktop settings. From a workload perspective, VR was generally considered the least mentally demanding and least frustrating to use in two of our three tasks. It was also preferred and ranked as the most effective and visually appealing condition overall. However, using VR to compare two side-by-side networks was difficult, and it was similar to or slower than other conditions in two of the three tasks. Overall, the accuracy and workload advantages of conditions with greater embodiment in specific tasks suggest promising opportunities to create more effective environments in which to analyze network visualizations.

Field-of-view correction in a VR HMD display with varifocal optics

Nowadays, we observe a progressive increase amount of virtual technologies application. VR devices, i.e. HMDs, are still struggling with the VAC. It is possible to “implement” the accommodation mechanism in HMDs using a varifocal system. By using focus tuneable lenses, we achieve high speed and smoothness of displacement of the virtual image plane. This solution involves also unfavourable changes of geometrical parameters of the projected image i.e. change in magnification. This can be solved by software modification parameters of the virtual camera. In this paper, the developed construction of varifocal HMD is presented, including the method of maintaining the constancy magnification. Full Text: PDF ReferencesY-J. Wang , Y-H. Lin, "Liquid crystal technology for vergenceaccommodation conflicts in augmented reality and virtual reality systems: a review", Liq. Cryst. Rev. 9. 35 (2021). CrossRef P.P. Monticone, M. Menozzi, M. Schlup, "Instrument for high-speed recording of accommodation of the human eye", Biomed. Tech. 55: 83 (2010). CrossRef G. Kramida, "Resolving the vergence-accommodation confict in headmounted displays", IEEE Trans. Vis. Comput. Graph. 22, 1912 (2016). CrossRef S. Shiwa, K. Omura, and F. Kishino, "Proposal for a 3-D display with accommodative compensation: 3DDAC," J. Soc. Inf. Disp. 4, 255 (1996). CrossRef K. Rathinavel, G. Wetzstein, H. Fuchs, "Varifocal Occlusion-Capable Optical See-through Augmented Reality Display based on Focus-tunable Optics," IEEE Trans. Vis. Comput. Graph. 25, 3125 (2019). CrossRef

P‐66: Application of Ergonomics in VR HMD Exit Pupil Positioning Design

To achieve the actual exit pupil distance and ensure display effect of the VR HMD, the positioning structure of exit pupil is studied from three aspects:design data extraction, experimental verification and data compensation. The surface model of sponge which is used to ensure the best fit between the sponge and face is extracted according to the data of ergonomic dimensions. The sponge designed with this model should be made to measure the actual exit pupil distance of the VR HMD by the method studied in this paper. The data of sponge compression from the test should be added to the size before. According to this method, the actual exit pupil distance can be closest to the design to achieve the best display effect.

Virtual Reality Head Mounted Display 기반 공군 조종사 모의 비행 훈련 시뮬레이터 파급효과에 관한 인식 연구

Objective: The purpose of this study is to compare Visual Monitor (VM)-based and Virtual Reality Head Mounted Display (VR HMD)-based simulated flight training simulators with respect to ripple effects.<BR>Background: VR HMD-based simulators can increase immersion and realism by providing more realistic virtual environments in comparison to VM-based simulators. Existing studies related to VR HMD-based simulators have been mainly focused on flight training effects of pilots rather than considering all the effects collectively.<BR>Method: This study conducted a comparative experiment of VM-based and VR HMD-based simulators with 25 Republic of Korea Air Force F-15K fighter pilots.<BR>Results: All 6 items on ripple effects were statistically significantly higher in VR HMDbased simulators than in VM-based simulators.<BR>Conclusion: When VR HMD-based simulators are used to with respect to ripple effects the flight training for Air Force pilots, practical technical ripple effects can be expected.<BR>Application: The results of this study are expected to help us understand the system characteristics of VR HMD-based simulators.

VR HMD 시뮬레이터를 활용한 조종사 시선 추적 및 착륙 절차 결과 분석

This study performed precision instrument landing procedures for pilots with a commercial pilot license using VR HMD flight simulators, and assuming that the center of the pilot's gaze is in the front, 3-D.O.F. head tracking data and 2-D eye tracking of VR HMD worn by pilots gaze tracking was performed through. After that, AOI (Area of Interesting) was set for the instrument panel and external field of view of the cockpit to analyze how the pilot's gaze was distributed before and after the decision altitude. At the same time, the landing results were analyzed using the Localizer and G/S data as the pilot's precision instrument landing flight data. As a result, the pilot was quantitatively evaluated by reflecting the gaze tracking and the resulting landing result using a VR HMD simulator.

A comparative experimental study of visual brain event-related potentials to a working memory task: virtual reality head-mounted display versus a desktop computer screen

Virtual reality head mounted display (VR HMD) systems are increasingly utilised in combination with electroencephalography (EEG) in the experimental study of cognitive tasks. The aim of our investigation was to determine the similarities/differences between VR HMD and the computer screen (CS) in response to an n-back working memory task by comparing visual electrophysiological event-related potential (ERP) waveforms (N1/P1/P3 components). The same protocol was undertaken for VR HMD and CS with participants wearing the same EEG headcap. ERP waveforms obtained with the VR HMD environment followed a similar time course to those acquired in CS. The P3 mean and peak amplitudes obtained in VR HMD were not significantly different to those obtained in CS. In contrast, the N1 component was significantly higher in mean and peak amplitudes for the VR HMD environment compared to CS at the frontal electrodes. Significantly higher P1 mean and peak amplitudes were found at the occipital region compared to the temporal for VR HMD. Our results show that successful acquisition of ERP components to a working memory task is achievable by combining VR HMD with EEG. In addition, the higher amplitude N1/P1 components seen in VR HMD indicates the potential utility of this VR modality in the investigation of early ERPs. In conclusion, the combination of VR HMD with EEG/ERP would be a useful approach to advance the study of cognitive function in experimental brain research.

Virtual Reality Head Mounted Display 기반 공군 조종사 모의비행 훈련 시뮬레이터 운용효과에 관한 연구

Objective: The purpose of this study is to compare Visual Monitor (VM)-based and Virtual Reality Head Mounted Display (VR HMD)-based simulated flight training simulators in terms of flight training effects, user experience effects.<BR>Background: VR HMD-based simulators can increase immersion and realism by providing more realistic virtual environments in comparison to VM-based simulators. Existing studies related to VR HMD-based simulators have been mainly focused on flight training effects of pilots rather than all the effects collectively.<BR>Method: This study conducted a comparative experiment of VM-based and VR HMD-based simulators with 25 Republic of Korea Air Force F-15K fighter pilots. The survey measured 20 detailed evaluation items related to flight training effects and user experience effects using a 7-point scale for the two simulators.<BR>Results: 5 out of 10 items on flight training effects, 8 out of 10 items on user experience effects were statistically significantly higher in VR HMD-based simulators than in VM-based simulators.<BR>Conclusion: When VR HMD-based simulators are used to the flight training for Air Force pilots, practical operational effects can be improved in terms of flight training effects, user experience effects.<BR>Application: The results of this study are expected to help us understand the system characteristics of VR HMD-based simulators.

A Smart Interface HUD Optimized for VR HMD and Leap Motion

Abstract Virtual reality head-mounted displays (VR HMDs) can provide three-dimensional content to increase user immersion that is relatively acceptable. However, user interactions with VR HMDs often do not satisfy a virtual environment. In this article, the authors propose a smart human‐computer interaction technique that runs on VR HMDs and Leap Motion. In this study, they focused on improving interaction methods for VR content and providing interfaces and information necessary for the operation of such content in a user-friendly manner, which should reduce fatigue and dizziness. To this end, they propose and validate a smart head-up display that is suitable for VR content. Specifically, a virtual head-up display (HUD) was designed and optimized for use with VR HMD and Leap Motion technologies. Additionally, they present comparative performance tests to validate the proposed system.

The lingula-sparing left upper segmentectomy presented here was performed for resection of a nodular lesion of left segment 1+2. The lesion was 20 mm in diameter. Based on preparation with the VR HMD, we quickly identified the variant PA vessel anatomy. We used ICG fluorescence to facilitate demarcation of the intersegmental border

The lingula-sparing left upper segmentectomy presented here was performed for resection of a nodular lesion of left segment 1+2. The lesion was 20 mm in diameter. Based on preparation with the VR HMD, we quickly identified the variant PA vessel anatomy. We used ICG fluorescence to facilitate demarcation of the intersegmental border

Immersive sketch-based tree modeling in virtual reality

Tree modeling has been a widely-discussed topic in computer graphics. However, with existing methods, the modeling process is occupied with complex data collection and tedious parameter adjustment, lacking a rich sensory modeling experience. In this paper, we propose an approach to sketch-based tree modeling in an immersive virtual reality environment, aiming to lower the difficulty of modeling and enhance the immersion in the designing process. We first present a sketch sampling and points optimization algorithm to obtain the skeleton of the branch in 3D space. As generating geometry along the skeleton, we apply a vector-projection method to fix the branch polygon twisting. Then, we introduce a bidirectional ray-hit algorithm to determine the branch radius as real-time sketching. To generate random twigs on branches, we introduce a twigs generation algorithm based on Perlin noise and the parent branch direction. Finally, we design a series of interactive methods for users to create tree models in a 3D virtual scene with the VR HMD and controller. Experimental results indicate that our approach can accomplish creating realistic tree models in real-time. The interactive and immersive modeling experience enables users to readily convey their ideas on tree structures in a simple and direct way of sketching. Visualizing and modifying the real-time generated branch results can contribute to provoking the inspiration for creation.

Accuracy of Time Duration Estimations in Virtual Reality

Virtual Reality Head Mounted Displays (VR HMDs) offer highly immersive experiences that may alter users’ awareness and perception of the “real-world”. This paper investigates users’ perception of short duration (&lt;5 minutes) time periods during simulated scenarios between two different simulation mediums. Fifty participants (Age: M=29.2 years; SD=10.7 years; 15 Females; 35 Males) were randomly assigned to one of two groups: (i) VR HMD or (ii) desktop computer configuration, where they performed identical searching tasks within a virtual environment three consecutive times. After each virtual session participants were asked to verbally report their perception of time duration. Results reveal that participants across both groups overestimated time duration in virtual environments by an average of 20.3%. As participants gained experience performing the task repeatedly across three consecutive attempts, their task completion time reduced (i.e. learning effect). However, participants’ accuracy of time perception continued to be consistently overestimated across both conditions.

Motor Program Transformation of Throwing Dart from the Third-Person Perspective.

The perspective of perceiving one’s action affects its speed and accuracy. In the present study, we investigated the change in accuracy and kinematics when subjects throw darts from the first-person perspective and the third-person perspective with varying angles of view. To model the third-person perspective, subjects were looking at themselves as well as the scene through the virtual reality head-mounted display (VR HMD). The scene was supplied by a video feed from the camera located to the up and 0, 20 and 40 degrees to the right behind the subjects. The 28 subjects wore a motion capture suit to register their right hand displacement, velocity and acceleration, as well as torso rotation during the dart throws. The results indicated that mean accuracy shifted in opposite direction with the changes of camera location in vertical axis and in congruent direction in horizontal axis. Kinematic data revealed a smaller angle of torso rotation to the left in all third-person perspective conditions before and during the throw. The amplitude, speed and acceleration in third-person condition were lower compared to the first-person view condition, before the peak velocity of the hand in the direction toward the target and after the peak velocity in lowering the hand. Moreover, the hand movement angle was smaller in the third-person perspective conditions with 20 and 40 angle of view, compared with the first-person perspective condition just preceding the time of peak velocity, and the difference between conditions predicted the changes in mean accuracy of the throws. Thus, the results of this study revealed that subject’s localization contributed to the transformation of the motor program.

Exploring virtual reality experiences of slum tourism

The popularity of slum tourism has been growing and is a topic of substantial discussion. Proponents suggest tours bring awareness and economic opportunity, whereas others critique their voyeuristic nature and claims of community benefits. Virtual reality head mounted displays (VR HMDs) have become relatively accessible in recent years creating a visually immersive experience of a different environment. VR technology is being used by tourism promoters as well as in education and training fields to acquaint people with foreign environments. This exploratory study draws from interviews with 16 participants who declared an interest in slum tourism. Participants discussed their experiences with, perceptions of, and motivations for visiting slum communities, and then watched a VR HMD tour of a slum in Manilla. Immediately following the video participants were asked for reactions and reflections, as well as at a subsequent meeting one to two weeks later. Findings show that the VR HMD was generally positively received, and many participants expressed a sense of trust in the representation of the community and experience because of the media’s immersive nature. Participants reported having their understandings of slum communities both reinforced and challenged, leading to more confidence that their awareness of issues in general, and slum tourism specifically, were realistic. Most participants felt more inspired, confident, and comfortable to actually take part in a tour, however some expressed concerns and described feeling less motivated to visit. Discussion includes critique of the video, as well as implications for research and practice.

Transverse Chromatic Aberrations in Virtual Reality Devices

We demonstrate a method for measuring the transverse chromatic aberration (TCA) in a virtual reality head-mounted display (VR HMD). This procedure was used to characterize the optical performance of the Oculus Go VR HMD. Results show a measurable TCA for angles larger than approximately 6◦ from the center of the field of view. TCA can be thought of as a wavelength dependent magnification, and as a result, the relative size of objects vary based on the rendering color. In addition, this leads to color changes in the image due to mixing with neighboring pixels, which impacts image quality. The test results for the Oculus Go show promise for characterizing TCA across different HMDs.

VR/AR head-mounted display system based measurement and evaluation of dynamic visual acuity

This study evaluated the dynamic visual acuity of candidates by implementing a King–Devick (K-D) test chart in a virtual reality head-mounted display (VR HMD) and an augmented reality head-mounted display (AR HMD). Hard-copy KD (HCKD), VR HMD KD (VHKD), and AR HMD KD (AHKD) tests were conducted in 30 male and female candidates in the age of 10S and 20S and subjective symptom surveys were conducted. In the subjective symptom surveys, all except one of the VHKD questionnaire items showed subjective symptoms of less than 1 point. In the comparison between HCKD and VHKD, HCKD was measured more rapidly than VHKD in all tests. In the comparison between HCKD and AHKD, HCKD was measured more rapidly than AHKD in Tests 1, 2, and 3. In the comparison between VHKD and AHKD, AHKD was measured more rapidly than VHKD in Tests 1, 2, and 3. In the correlation analyses of test platforms, all platforms were correlated with each other, except for the correlation between HCKD and VHKD in Tests 1 and 2. There was no significant difference in the frequency of errors among Tests 1, 2, and 3 across test platforms.VHKD and AHKD, which require the body to be moved to read the chart, required longer measurement time than HCKD. In the measurements of each platform, AHKD was measured closer to HCKD than VHKD, which may be because the AHKD environment is closer to the actual environment than the VHKD environment. The effectiveness of VHKD and AHKD proposed in this research was evaluated experimentally. The results suggest that treatment and training could be performed concurrently through the use of clinical test and content development of VHKD and AHKD.

Strategies and tactics in Skyrim through virtual reality: the VR–HMD as a model for disciplining in the twenty-first century

ABSTRACTThis article is about the Virtual Reality-Head Mounted Display (VR-HMD) as a model for contemporary ways of disciplining. The VR-HMD makes the observer discipline herself through the triggering of performance. Through specific strategies the VR-HMD addresses the body of the observer to perform in the mixed reality that is constructed in the interaction between the body and the VR-HMD. These strategies consist of approaches by the hardware developers and content creators to manage the subjectivity and visuality of the observer. Today’s body is not disciplined through formatted technics of the VR-HMD, but through self-disciplining of the observer’s active performance. This article will unravel the strategies within the game The Elder Scrolls V: Skyrim VR on the Playstation VR that are used to control the visuality and subjectivity. Through her interaction in the game the observer also becomes aware of her body and the ways that it is disciplined in. In the end, this article will argue that the VR-HMD should not only be understood as a strategic device that can discipline a neoliberal subject, but that the VR-HMD is a supercomplex intervention that could help us to become more corporeal literate of our bodies in the age of digital media.