Expert evaluation of aspects related to virtual reality systems and suggestions for future studies

Abstract. In this bachelor’s thesis, we review existing quantitative and qualitative research on virtual reality systems. We then present suggestions for performing a future study to combine the objective and subjective measurements of virtual reality experience. Additionally, we adapted an existing heuristics-based expert evaluation method to suit evaluating virtual reality systems. Using our method, we performed the expert evaluation on a selection of five modern consumer virtual reality systems to understand the connections between the subjective experience and the physical variables related to the virtual reality system. From this evaluation, we present findings that are used to construct discussion and to draw conclusions on these said connections. We found the most prominent conclusion to be that the experience of virtual reality is highly subjective and dependent on the content being viewed in virtual reality. Additionally, we concluded that some of the most important aspects in need of improvement are display resolution, lens design, user ergonomics, and lack of wirelessness. Finally, we state that two optimization problems are present; the first one being the optimization required to design a virtual reality system and the second one being the act of choosing a system to match a consumer’s preferred content.Tiivistelmä. Tässä kandidaatin tutkielmassa käymme läpi aiempaa kvantitatiivista ja kvalitatiivista tutkimusta virtuaalitodellisuusjärjestelmistä. Esitämme myös ehdotuksia myöhempää tutkimusta varten virtuaalitodellisuuteen liittyvien objektiivisten ja subjektiivisten mittausten yhdistämiseksi. Tämän lisäksi adaptoimme aiemman heuristiikkapohjaisen asiantuntija-arvioinnin sopimaan virtuaalitodellisuusjärjestelmien arviointiin. Käyttäen metodiamme toteutimme asiantuntija-arvioinnin viidellä modernilla kuluttajakäyttöön tarkoitetulla virtuaalitodellisuusjärjestelmällä ymmärtääksemme yhteyksiä subjektiivisen kokemuksen ja niiden fysikaalisten muuttujien välillä, jotka liittyvät virtuaalitodellisuusjärjestelmiin. Esitämme tämän asiantuntija-arvioinnin löydöksiä, ja luomme niiden avulla keskustelua, jonka avulla teemme mainittuihin yhteyksiin liittyviä johtopäätöksiä. Tärkein johtopäätöksemme oli se, että virtuaalitodellisuuden kokemus on erittäin subjektiivinen ja riippuvainen siitä sisällöstä, jota virtuaalitodellisuudessa koetaan. Aiemman lisäksi toteamme, että merkittävimpiä kehitystä kaipaavia osa-alueita ovat näytön resoluutio, linssien suunnittelu, käyttäjäergonomia ja langattomuuden puute. Viimeisenä totesimme, että virtuaalitodellisuusjärjestelmiin liittyy kaksi optimointiongelmaa; ensimmäinen liittyy järjestelmän suunnittelussa tapahtuvaan optimointiin, ja toinen liittyy sellaisen järjestelmän valitsemiseen, joka sopii kunkin kuluttajan suosimaan tarkoitukseen

Identification Of System Design Features That Affect Sickness In Virtual Environments

The terms simulator and VR are typically used to refer to specific types of virtual environments (VEs) which differ in the technology used to display the simulated environment. While simulators and VR devices may offer advantages such as low cost training, numerous studies on the effects to humans of exposure to different VEs indicate that motion sickness-like symptoms are often produced during or after exposure to the simulated environment. These deleterious side effects have the potential to limit the utilization of VE systems if they jeopardize the health and/or safety of the user and create liability issues for the manufacturer. The most widely used method for assessing the adverse symptoms of VE exposure is the Simulator Sickness Questionnaire (SSQ). The method of scoring the symptoms reported by VE users permits the different sickness symptoms to be clustered into three general types of effects or subscales and the distribution or pattern of the three SSQ subscales provides a profile for a given VE device. In the current research, several different statistical analyses were conducted on the SSQ data obtained from 21 different simulator studies and 16 different VR studies in order to identify an underlying symptom structure (i.e., SSQ profile) or severity difference for various types of VE systems. The results of the research showed statistically significant differences in the SSQ profiles and the overall severity of sickness between simulator and VR systems, which provide evidence that simulator sickness and VR sickness represent distinct forms of motion sickness. Analyses on three types of simulators (i.e., Fixed- and Rotary-Wing flight simulators and Driving simulators) also found significant differences in the sickness profiles as well as the overall severity of sickness within different types of simulator systems. Analyses on three types of VR systems (i.e., HMD, BOOM, and CAVE) revealed that BOOM and CAVE systems have similar sickness profiles, which are different than the HMD system profile. Moreover, the results showed that the overall severity of sickness was greater in HMD systems than in BOOM and CAVE systems. Recommendations for future research included additional psychophysical studies to evaluate the relationship between various engineering characteristics of VE systems and the specific types of sickness symptoms that are produced from exposure to them

Visual discomfort whilst viewing 3D stereoscopic stimuli

3D stereoscopic technology intensifies and heightens the viewer s experience by adding an extra dimension to the viewing of visual content. However, with expansion of this technology to the commercial market concerns have been expressed about the potential negative effects on the visual system, producing viewer discomfort. The visual stimulus provided by a 3D stereoscopic display differs from that of the real world, and so it is important to understand whether these differences may pose a health hazard. The aim of this thesis is to investigate the effect of 3D stereoscopic stimulation on visual discomfort. To that end, four experimental studies were conducted. In the first study two hypotheses were tested. The first hypothesis was that the viewing of 3D stereoscopic stimuli, which are located geometrically beyond the screen on which the images are displayed, would induce adaptation changes in the resting position of the eyes (exophoric heterophoria changes). The second hypothesis was that participants whose heterophoria changed as a consequence of adaptation during the viewing of the stereoscopic stimuli would experience less visual discomfort than those people whose heterophoria did not adapt. In the experiment an increase of visual discomfort change in the 3D condition in comparison with the 2D condition was found. Also, there were statistically significant changes in heterophoria under 3D conditions as compared with 2D conditions. However, there was appreciable variability in the magnitude of this adaptation among individuals, and no correlation between the amount of heterophoria change and visual discomfort change was observed. In the second experiment the two hypotheses tested were based on the vergence-accommodation mismatch theory, and the visual-vestibular mismatch theory. The vergence-accommodation mismatch theory predicts that a greater mismatch between the stimuli to accommodation and to vergence would produce greater symptoms in visual discomfort when viewing in 3D conditions than when viewing in 2D conditions. An increase of visual discomfort change in the 3D condition in comparison with the 2D condition was indeed found; however the magnitude of visual discomfort reported did not correlate with the mismatch present during the watching of 3D stereoscopic stimuli. The visual-vestibular mismatch theory predicts that viewing a stimulus stereoscopically will produce a greater sense of vection than viewing it in 2D. This will increase the conflict between the signals from the visual and vestibular systems, producing greater VIMS (Visually- Induced Motion Sickness) symptoms. Participants did indeed report an increase in motion sickness symptoms in the 3D condition. Furthermore, participants with closer seating positions reported more VIMS than participants sitting farther away whilst viewing 3D stimuli. This suggests that the amount of visual field stimulated during 3D presentation affects VIMS, and is an important factor in terms of viewing comfort. In the study more younger viewers (21 to 39 years old) than older viewers (40 years old and older) reported a greater change in visual discomfort during the 3D condition than the 2D condition. This suggests that the visual system s response to a stimulus, rather than the stimulus itself, is a reason for discomfort. No influence of gender on viewing comfort was found. In the next experiment participants fusion capability, as measured by their fusional reserves, was examined to determine whether this component has an impact on reported discomfort during the watching of movies in the 3D condition versus the 2D condition. It was hypothesised that participants with limited fusional range would experience more visual discomfort than participants with a wide fusion range. The hypothesis was confirmed but only in the case of convergent and not divergent eye movement. This observation illustrates that participants capability to convergence has a significant impact on visual comfort. The aim of the last experiment was to examine responses of the accommodation system to changes in 3D stimulus position and to determine whether discrepancies in these responses (i.e. accommodation overshoot, accommodation undershoot) could account for visual discomfort experienced during 3D stereoscopic viewing. It was found that accommodation discrepancy was larger for perceived forwards movement than for perceived backwards movement. The discrepancy was slightly higher in the group susceptible to visual discomfort than in the group not susceptible to visual discomfort, but this difference was not statistically significant. When considering the research findings as a whole it was apparent that not all participants experienced more discomfort whilst watching 3D stereoscopic stimuli than whilst watching 2D stimuli. More visual discomfort in the 3D condition than in the 2D condition was reported by 35% of the participants, whilst 24% of the participants reported more headaches and 17% of the participants reported more VIMS. The research indicates that multiple causative factors have an impact on reported symptoms. The analysis of the data suggests that discomfort experienced by people during 3D stereoscopic stimulation may reveal binocular vision problems. This observation suggests that 3D technology could be used as a screening method to diagnose un-treated binocular vision disorder. Additionally, this work shows that 3D stereoscopic technology can be easily adopted to binocular vision measurement. The conclusion of this thesis is that many people do not suffer adverse symptoms when viewing 3D stereoscopic displays, but that if adverse symptoms are present they can be caused either by the conflict in the stimulus, or by the heightened experience of self-motion which leads to Visually-Induced Motion Sickness (VIMS)

A head-mounted display as a personal viewing device : Dimensions of subjective experiences

The use of head-mounted displays (HMDs) can produce both positive and negative experiences. In an effort increase positive experiences and avoid negative ones, researchers have identified a number of variables that may cause sickness and eyestrain, although the exact nature of the relationship to HMDs may vary, depending on the tasks and the environments. Other non-sickness-related aspects of HMDs, such as users opinions and future decisions associated with task enjoyment and interest, have attracted little attention in the research community. In this thesis, user experiences associated with the use of monocular and bi-ocular HMDs were studied. These include eyestrain and sickness caused by current HMDs, the advantages and disadvantages of adjustable HMDs, HMDs as accessories for small multimedia devices, and the impact of individual characteristics and evaluated experiences on reported outcomes and opinions. The results indicate that today s commercial HMDs do not induce serious sickness or eyestrain. Reported adverse symptoms have some influence on HMD-related opinions, but the nature of the impact depends on the tasks and the devices used. As an accessory to handheld devices and as a personal viewing device, HMDs may increase use duration and enable users to perform tasks not suitable for small screens. Well-designed and functional, adjustable HMDs, especially monocular HMDs, increase viewing comfort and usability, which in turn may have a positive effect on product-related satisfaction. The role of individual characteristics in understanding HMD-related experiences has not changed significantly. Explaining other HMD-related experiences, especially forward-looking interests, also requires understanding more stable individual traits and motivations.Päässä pidettävän näytön käyttö voi olla mukava kokemus ilman silmärasituksen tai pahoinvoinnin oireita. Joskus siihen voi liittyä myös erilaisia negatiivisia tuntemuksia. Vuosien varrella on tunnistettu monia systeemiin, käyttäjään ja tehtävään liittyviä taustamuuttujia, joilla on vaikutusta negatiivisten tuntemusten ja kokemusten syntyyn. Muita, päässä pidettävän näytön käyttöön liittyviä kokemuksia ja käyttäjien mielipiteitä on tutkittu vain vähän tai ei ollenkaan. Tässä väitöskirjassa tutkittiin markkinoilla olevien erilaisten päässä pidettävien näyttöjen käyttökokemuksia. Yksityiskohtaisemmin tarkasteltiin päässä pidettävien näyttöjen käyttöön liittyvä silmärasitusta ja pahoinvointia sekä näytön säätömahdollisuuden hyötyjä ja haittoja käyttäjän näkökulmasta. Lisäksi tutkittiin laitteen käyttöä lisälaitteena muille pienille multimedialaitteille sekä sitä, miten erilaiset taustamuuttujat ja laitteen käyttöön liittyvät kokemukset auttavat meitä ymmärtämään laitteen tulevaan käyttöön liittyviä mielipiteitä. Tässä väitöskirjassa esitettyjen tutkimustulosten mukaan päässä pidettävät näytöt voivat aiheuttaa lievää silmärasitusta ja pahoinvointia, mutta erot muihin näyttöihin ovat selvästi pienentyneet. Päässä pidettävän näytön säätömahdollisuus parantaa katselukokemusta etenkin monokulaarisen päässä pidettävän näytön tapauksessa, mutta näyttöjen säädettävyys voi hyödyttää myös bi-okulaaristen näyttöjen käyttäjiä. Päässä pidettävän näytön käyttö lisälaitteena pienille multimedialaitteille pidentää sovelluksen käyttöaikaa ja mahdollistaa sellaisten tehtävien suorituksen, jotka olisivat erittäin vaativia pienellä näytöllä. Aikaisemmin julkaistujen tulosten mukaan monet käyttäjän yksilölliset ominaisuudet auttavat ymmärtämään koettua silmärasitusta ja pahoinvointia. Myös väitöskirjassa esitetyt tulokset tukevat tätä näkemystä. Johtopäätöksenä voidaankin esittää, että jos tavoitteena on ymmärtää laitteen tulevaan käyttöön liittyviä mielipiteitä, niin välittömien käyttökokemusten lisäksi pitäisi tarkastella myös käyttäjän persoonallisuuspiirteiden ja motivaatioiden vaikutusta

A study on virtual reality and developing the experience in a gaming simulation

A thesis submitted to the University of Bedfordshire in partial fulfilment of the requirements for the degree of Masters by ResearchVirtual Reality (VR) is an experience where a person is provided with the freedom of viewing and moving in a virtual world [1]. The experience is not constrained to a limited control. Here, it was triggered interactively according to the user’s physical movement [1] [2]. So the user feels as if they are seeing the real world; also, 3D technologies allow the viewer to experience the volume of the object and its prospection in the virtual world [1]. The human brain generates the depth when each eye receives the images in its point of view. For learning for and developing the project using the university’s facilities, some of the core parts of the research have been accomplished, such as designing the VR motion controller and VR HMD (Head Mount Display), using an open source microcontroller. The VR HMD with the VR controller gives an immersive feel and a complete VR system [2]. The motive was to demonstrate a working model to create a VR experience on a mobile platform. Particularly, the VR system uses a micro electro-mechanical system to track motion without a tracking camera. The VR experience has also been developed in a gaming simulation. To produce this, Maya, Unity, Motion Analysis System, MotionBuilder, Arduino and programming have been used. The lessons and codes taken or improvised from [33] [44] [25] and [45] have been studied and implemented

Immersive Visualization in Biomedical Computational Fluid Dynamics and Didactic Teaching and Learning

Virtual reality (VR) can stimulate active learning, critical thinking, decision making and improved performance. It requires a medium to show virtual content, which is called a virtual environment (VE). The MARquette Visualization Lab (MARVL) is an example of a VE. Robust processes and workflows that allow for the creation of content for use within MARVL further increases the userbase for this valuable resource. A workflow was created to display biomedical computational fluid dynamics (CFD) and complementary data in a wide range of VE’s. This allows a researcher to study the simulation in its natural three-dimensional (3D) morphology. In addition, it is an exciting way to extract more information from CFD results by taking advantage of improved depth cues, a larger display canvas, custom interactivity, and an immersive approach that surrounds the researcher. The CFD to VR workflow was designed to be basic enough for a novice user. It is also used as a tool to foster collaboration between engineers and clinicians. The workflow aimed to support results from common CFD software packages and across clinical research areas. ParaView, Blender and Unity were used in the workflow to take standard CFD files and process them for viewing in VR. Designated scripts were written to automate the steps implemented in each software package. The workflow was successfully completed across multiple biomedical vessels, scales and applications including: the aorta with application to congenital cardiovascular disease, the Circle of Willis with respect to cerebral aneurysms, and the airway for surgical treatment planning. The workflow was completed by novice users in approximately an hour. Bringing VR further into didactic teaching within academia allows students to be fully immersed in their respective subject matter, thereby increasing the students’ sense of presence, understanding and enthusiasm. MARVL is a space for collaborative learning that also offers an immersive, virtual experience. A workflow was created to view PowerPoint presentations in 3D using MARVL. A resulting Immersive PowerPoint workflow used PowerPoint, Unity and other open-source software packages to display the PowerPoint presentations in 3D. The Immersive PowerPoint workflow can be completed in under thirty minutes

EVALUATION OF VISUALLY INDUCED MOTION SICKNESS CAUSED BY VIEWING OF 3D STEREOSCOPY USING ELECTROENCEPHALOGRAPHY TECHNIQUE

The 3D movies are attracting the viewers as they see objects flying out of the screen. However, many viewers reportof problems that they face after watching 3D movies. Visual fatigue, eye strain, headaches, dizziness, blurred vision or in other words, Visually Induced Motion Sickness (VIMS) are reported by viewers of 3D movies. In this thesis, we aim to compare a 3D passive technology with a conventional 2D technology to find whether 3D is causing trouble in the viewers or not

Multimodality in VR: A survey

Virtual reality (VR) is rapidly growing, with the potential to change the way we create and consume content. In VR, users integrate multimodal sensory information they receive, to create a unified perception of the virtual world. In this survey, we review the body of work addressing multimodality in VR, and its role and benefits in user experience, together with different applications that leverage multimodality in many disciplines. These works thus encompass several fields of research, and demonstrate that multimodality plays a fundamental role in VR; enhancing the experience, improving overall performance, and yielding unprecedented abilities in skill and knowledge transfer