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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

Interior Design and Navigation in Virtual Reality / Inredning och Navigation i Virtuell Verklighet

Tingvall, Jesper January 2015 (has links)
This thesis examined how virtual reality could be used in interior design. The thesis was limited to virtual reality experienced using a head mounted display. The Method was to integrate virtual reality into an existing interior design software called CET Designer. After investigating the available commercial virtual reality hardware and software Oculus SDK and OpenVR was chosen. Unity 3D was used as a prototyping tool for experimenting with different interaction and navigation methods. An user study with 14 participants was performed. It compared four different navigation methods. First person shooter style controls using a gamepad was proven to be the best one. It can also be concluded that having a bad navigation style could decreased the user experience in virtual reality and cause motion sickness.
22

Methods for Generating Addressable Focus Cues in Stereoscopic Displays

LIU, SHENG January 2010 (has links)
Conventional stereoscopic displays present a pair of stereoscopic images on a single and fixed image plane decoupled with the vergence and accommodation responses of the viewer. In consequence, these displays lack the capability of correctly rendering focus cues (i.e. accommodation and retinal blur) and may induce the discrepancy between accommodation and convergence. A number of visual artifacts associated with incorrect focus cues in stereoscopic displays have been reported, limiting the applicability of these displays for demanding applications and daily usage.In this dissertation, methods and apparatus for generating addressable focus cues in conventional stereoscopic displays are proposed. Focus cues can be addressed throughout a volumetric space, either through dynamically varying the focal distance of a display enabled by an active optical element or by multiplexing a stack of 2-D image planes. Optimal depth-weighted fusing functions are developed to fuse a number of discrete image planes into a seamless volumetric space with continuous and near-correct focus cues similar to the real world counterparts.The optical design, driving methodology, and prototype implementation of the addressable focus displays are presented and discussed. Experimental results demonstrate continuously addressable focus cues from infinity to as close as the near eye distance. Experiments to further evaluate the depth perception in the display prototype are conducted. Preliminary results suggest that the perceived distance and accommodative response of the viewer match with the addressable accommodation cues rendered by the display, approximating the real-world viewing condition.
23

Crossmodal integration with a head-mounted display and auditory display options: is there cause for concern?

Thompson, Matthew B. Unknown Date (has links)
Head-Mounted Displays (HMDs) are increasingly used to support mobile work (Laramee & Ware, 2002). Human operators sometimes require additional auditory support when using an HMD, which raises the question of whether sound is better delivered publicly in free-field or privately via earpiece. A novel experimental procedure was created in which participants had to identify mismatches between auditory information and visual information on an HMD. Different conditions of sound delivery and physical movement were manipulated within-subjects. Participants heard the sound either via earpiece or free-field while they either sat or moved about the test room. Predictions were based on the idea that inconsistent spatial mapping of vision and sound would compromise mismatch detection. First, I predicted a main effect of movement such that participants‟ mismatch detection would be worse when they moved than when they sat. Second, I predicted an interaction between movement and sound delivery. When participants are seated there will be no difference in mismatch detection between the two methods of sound delivery. When participants are walking, however, mismatch detection will be better with an earpiece than with free-field delivery. Results supported the first prediction. For the second prediction, the significant interaction found took a different form than predicted. With the earpiece, participants performed equally well whether sitting or walking, but with free-field sound, participants performed better when sitting than when walking. Results have implications for understanding necessary auditory conditions for effective crossmodal integration and may indicate a cause for concern for people who use HMDs and auditory displays in safety-critical environments.
24

Forest thinning in VR : A VR application with the theme of forest thinning

Astner, Thomas January 2018 (has links)
The purpose with this project was to create a virtual reality game were the users should be able to carry out a thinning. The main goals are to use real forests terrains as terrain models in the game, the GameObjects and the teleportation system in the application should be able to handle changing terrains and the application should not cause virtual reality sickness. The application has been developed with the help of the game engine Unity and plugins from Unitys own asset store. User tests and measurements will be carried out in order to evaluate if the game causes virtual reality sickness or not. The results shows that it is possible to use real forests terrains and that the solution is suited for this application. The downside is that in order to use real life terrains several steps has to be taken and that the terrain object has to be designed manually. It also shows that the GameObjects and the Teleportation system has been implemented in a way so they can handle changing terrains. Furthermore it shows that some of the functionalities of the application could be improved, especially the scoring system. The users tests and the measurements showed that the application isn't causing virtual reality sickness but it also showed that the users feels like there are things missing in the application
25

Input and Display of Text for Virtual Reality Head-Mounted Displays and Hand-held Positionally Tracked Controllers

Olofsson, Jakob January 2017 (has links)
The recent increase of affordable virtual reality (VR) head-mounted displays has led to many new video games and applications being developed for virtual reality environments. The improvements to VR technology has introduced many new possibilities, but has also introduced new problems to solve in order to make VR software as comfortable and as effective as possible. In this report, different methods of displaying text and receiving text input in VR environments are investigated and measured. An interactive user study was conducted to evaluate and compare the performance and user opinion of three different text display methods and four separate virtual keyboard solutions. Results revealed that the distance between text and user, with the same relative text size, significantly affected the ease of reading the text, and that designing a good virtual keyboard for VR requires a good balance of multiple factors. An example of such factors is the balance between precise control and the amount of physical exertion required. Additionally, the results suggest that the amount of previous experience with virtual reality equipment, and typing skill with regular physical keyboards, can meaningfully impact which solution is most appropriate. / Den senaste tidens ökning av prisvärda virtual reality (VR) glasögon har lett till en ökning av spel och applikationer som utvecklas för virtual reality miljöer. Förbättringarna av VR tekniken har introducerat många nya möjligheter, men även nya problem att lösa för att skapa VR mjukvara som är så bekväm och effektiv som möjligt. I den här rapporten undersöks och mäts olika metoder för att visa samt ta emot text i VR miljöer. Detta undersöktes genom utförandet av en interaktiv användarstudie som utvärderade och jämförde effektiviteten och användaråsikter kring tre olika metoder för att visa text samt fyra olika virtuella tangentbordslösningar. Resultatet visade att avståndet mellan användaren och texten, med samma relativa textstorlek, avsevärt påverkade lättheten att läsa texten, samt att designen av ett bra virtuellt tangentbord för VR kräver en bra balans mellan flera faktorer. Ett exempel på sådana faktorer är balansen mellan noggrann kontroll och den fysiska ansträngning som krävs. Resultatet tyder även på att mängden av tidigare erfarenhet med virtual reality utrustning samt skicklighet att skriva med vanliga fysiska tangentbord betydligt kan påverka vilka lösningar som är mest passande för situationen.
26

Navigating using 360° Panoramic Video : Design Challenges and Implications

Ulenius, Magnus January 2017 (has links)
In recent years, technological developments have led to the emergence of 360°. Google Street Map has provided panoramic imagery for a number of years, where users can immerse themselves and pan around in scenarios and follow streets of their liking, familiarizing and navigating themselves with the location. However, this service supports neither video nor moving imagery. This paper explores the use of 360° panoramic videos as a navigation aid on two different platforms as well as consider more subjective perspectives from potential users. The study is conducted through a set of interviews and a focus group where the findings reveal a number of design challenges concerning the development of a navigational system based on 360° panoramic videos. Based on these findings, design challenges are presented and later summarized as three design recommendations; 1) Design for navigation in a panoramic scenery, 2) Support overview and traditional navigation, 3) Support custom tailored features and content. The studies also suggest that the use of a head-mounted display (HMD) increase the feeling of presence which is beneficial for navigational purposes however, the users in this study preferred the mobile device based on practicality.
27

Optical methods for enabling focus cues in head-mounted displays for virtual and augmented reality

Hua, Hong 10 May 2017 (has links)
Developing head-mounted displays (HMD) that offer uncompromised optical pathways to both digital and physical worlds without encumbrance and discomfort confronts many grand challenges, both from technological perspectives and human factors. Among the many challenges, minimizing visual discomfort is one of the key obstacles. One of the key contributing factors to visual discomfort is the lack of the ability to render proper focus cues in HMDs to stimulate natural eye accommodation responses, which leads to the well-known accommodation-convergence cue discrepancy problem. In this paper, I will provide a summary on the various optical methods approaches toward enabling focus cues in HMDs for both virtual reality (VR) and augmented reality (AR).
28

Real Time Vehicle Diagnostics Using Head Mounted Displays

Enblom, Gustav, Eskebaek, Hannes January 2015 (has links)
This thesis evaluates how a head mounted display (HMD) can be used to increase usability compared to existing computer programs that are used during maintenance work on vehicles. Problems identified during a case study in a vehicle workshop are first described. As an attempt to solve some of the identified problems a prototype application using a HMD was developed. The prototype application aids the user during troubleshooting of systems on the vehicle by leading the mechanic with textual information and augmented reality (AR). Assessment of the prototype application was done by comparing it to the existing computer program and measuring error rate and time to completion for a predefined task. Usability was also measured using the System Usability Scale. The assessment showed that HMDs can provide higher usability in terms of efficiency and satisfaction. Furthermore, the thesis describes and discusses other possibilities and limitations that usage of HMDs and AR can lead to that were identified both from theory and during implementation.
29

Locomotion in Virtual Reality for Room Scale Tracked Areas

Bozgeyikli, Evren 10 November 2016 (has links)
In the recent years, virtual reality has been used as an effective tool for a wide range of areas such as training, rehabilitation, education and games. The affordability of the new generation headsets helped this medium to become more widespread. However, in order for virtual reality to become mainstream, more content that is specifically designed for this medium is needed. Since virtual reality is a different technology than the computer systems, different design principles may be required for these content for better user experience. One of the crucial components of virtual reality applications is locomotion, since the viewpoint of the user is very important in immersing the users into virtual reality and locomotion is used for moving the viewpoint of user in virtual environments. Locomotion in virtual reality is expected to have a direct effect on user experience in terms of many elements such as effort, enjoyment, frustration, motion sickness and presence. Up to date, many locomotion techniques for virtual reality have been studied in the literature. However, many of these techniques were evaluated in large tracked areas. Although professional motion tracking systems can track large areas, today’s new generation affordable commercial virtual reality systems can only track room scale environments. This dissertation aims at evaluating different locomotion techniques in room scale tracked areas for neurotypical individuals and individuals with ASD. Several previous studies concurred that virtual reality is an effective medium for the training and rehabilitation of individuals with ASD. However, no previous study evaluated locomotion in virtual reality for this specific population. Thus, this dissertation aims at finding out the suitable virtual reality locomotion techniques for individuals with ASD. With these motivations, in this dissertation, locomotion techniques for room scale virtual reality were evaluated under three experiments: virtual reality for vocational rehabilitation system, evaluation of eight virtual reality locomotion techniques, and point & teleport direction specification experiment. In the first experiment of virtual reality for vocational rehabilitation system, locomotion, interaction, and display components in an immersive virtual reality system for vocational rehabilitation was evaluated by 10 neurotypical individuals and 9 individuals with high functioning ASD. The results indicated that neurotypical individuals favored real walking over walk-in-place; tangible interaction over haptic device, touch & snap and touch screen; and head mounted display over curtain screen. For the participants with high functioning ASD, real walking was favored over walk-in-place; touch screen was favored over haptic device, tangible interaction and touch & snap; and curtain screen was favored over head mounted display. In the second experiment, eight virtual reality locomotion techniques were evaluated in a room scale tracked area (2m by 2m). These eight locomotion techniques were: redirected walking, walk-in-place, stepper machine, point & teleport, joystick, trackball, hand flapping and flying. Among these locomotion techniques, the three were commonly used in virtual reality (redirected walking, walk-in-place and joystick), the two were unexplored –explored previously only by a few related studies (stepper machine and point & teleport), and the three were selected and/or modified for individuals with ASD based on their common characteristics (trackball, hand flapping and flying). These eight techniques were evaluated in an immersive virtual reality test environment. A user study was performed with 16 neurotypical participants and 15 participants with high functioning ASD. The results indicated that for neurotypical individuals, point & teleport, joystick and redirected walking were suitable virtual reality locomotion techniques for room scale tracked areas whereas hand flapping and flying were not suitable. For individuals with high functioning ASD, point & teleport, joystick and walk-in-place were suitable virtual reality locomotion techniques for room scale tracked areas whereas hand flapping and flying were not suitable. Locomotion techniques that are similar to point & teleport have been starting to be used in commercial video games, however were not evaluated in the literature. For this reason, a separate experiment was performed as the third experiment to investigate the effects of an additional direction specification component of point & teleport. Since this direction specification component exerted an additional cognitive load into the use of the same technique, which was recommended to be avoided for individuals with ASD in the literature, it was only evaluated by neurotypical individuals. An immersive virtual maze environment was developed and a user study was performed with 16 neurotypical users. The results indicated that the additional direction specification feature did not improve the user experience.
30

Approche dynamique de formation d'image et de compensation d'aberrations pour un système de réalité augmentée / Dynamic approach for imaging and aberration compensation in an augmented reality display

Beuret, Marc 29 June 2012 (has links)
La réalité augmentée consiste à superposer à l’environnement réel des informations virtuelles générées numériquement. Parmi les systèmes qui permettent de réaliser un tel mélange, nous nous intéressons dans ce travail aux systèmes de visualisation en réalité augmentée liés à la tête de l’utilisateur, généralement appelés HMD (Head-Mounted Display). Dans un tel système, la superposition des informations virtuelles à l’environnement réel peut être réalisée par un élément optique (optique mélangeuse) positionné devant l’oeil de l’utilisateur. La conception d’un système HMD est cependant une tâche complexe. En effet, la proximité de la tête introduit des contraintes géométriques importantes et provoque des déformations (aberrations) des images virtuelles. Généralement, ces aberrations sont minimisées de façon simultanée sur l’ensemble du champ de vision de l’utilisateur. Cette optimisation du système se fait néanmoins soit au détriment de la compacité ce qui s’avère problématique pour le confort d’utilisation du HMD, soit au détriment de la qualité de l’image au centre du champ de vision. Nous proposons dans ce travail ce qui nous semble être une nouvelle approche de conception en associant un modulateur spatial de lumière (SLM) et une optique mélangeuse diffractive statique. L’image virtuelle est créée séquentiellement point par point en modifiant l’incidence sous laquelle on éclaire l’optique mélangeuse. Le SLM permet d’adapter dynamiquement la correction des aberrations associées à chaque point virtuel. Nous avons dans un premier temps défini la fonction optique de l’optique mélangeuse diffractive et le champ de vision maximal (18° x 18°) qu’il est possible d’atteindre en respectant les contraintes géométriques d’utilisation. Nous avons pu alors montrer théoriquement que l’approche proposée permet d’atteindre une qualité d’image optimale sur l’ensemble du champ de vision. Les fonctions de correction sont réalisables avec les technologies actuelles. La validation expérimentale de ces résultats a été réalisée. / Augmented reality (AR) supplements the real world with computer-generated objects that appear to coexist in the same space as the real world. Among the systems that achieve such a mixture, we focus in this work on augmented reality head mounted displays (HMD). In such a system, the superimposition of virtual information to the real environment can be achieved by a combiner. This combiner is an optical element positioned in front of the eye of the user. It is a complex challenge to design an HMD. They generally have off-axis configurations because of the proximity of the head of the user. The optical system therefore suffers for high geometrical aberrations as Gauss conditions are not respected. Usually, these aberrations are minimized simultaneously on the entire field of vision of the user. However, such a simultaneous approach implies either a loss of compactness or a loss of the quality of the image. We propose in this work a novel design for an augmented reality HMD. We studied an optical system associating a dynamic element (spatial light modulator) and a static diffractive combiner. The virtual image is created sequentially point by point by illuminating the diffractive combiner with different incidences. The SLM allows to adapt, in a dynamical way, the correction of the aberrations associated to each position of the virtual point. We initially defined the phase transfer function of the diffractive combiner. We showed that it is possible to reach a 18° by 18° field of view considering the geometrical constraints. Then, we proved theoretically that the proposed approach can achieve an optimal image quality over the entire field of view. We demonstrated that it is possible to realize the correction functions with current technologies. The experimental validation of the results was performed.

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