Depending upon their nature, Outdoor AR applications can be deployed on head mounted displays (HMD) like Google glass or handheld Displays (HHD) like smartphones. This master’s thesis investigates novel gesture-based interaction techniques and applications for a HMD-HHD hybrid system that account for advantages presented by each platform. Prior research in HMD-HHD hybrid systems and gestures used in VR and surface computing were taken into account while designing the applications and interaction techniques. A prototype system combining a HMD and HHD was developed and four applications were created for the system. For evaluating the gestures, an application that compared four of the proposed gestures for selection tasks was developed. The results showed a significant difference between the different gestures and that the choice of gesture for selection tasks using a hybrid system depended upon application requirements like speed and accuracy.

Virtual reality (VR) headsets are becoming more common and will require evolving input mechanisms to support a growing range of applications. Because VR devices require users to wear head-mounted displays, there are accomodations that must be made in order to support specific input devices. One such device, a keyboard, serves as a useful tool for text entry. Many users will require assistance towards using a keyboard when wearing a head-mounted display. Developers have explored new mechanisms to overcome the challenges of text-entry for virtual reality. Several games have toyed with the idea of using motion controllers to provide a text entry mechanism, however few investigations have made on how to assist users in using a physical keyboard while wearing a head-mounted display. As an alternative to controller based text input, I propose that a software tool could facilitate the use of a physical keyboard in virtual reality. Using computer vision, a user€™s hands could be projected into the virtual world. With the ability to see the location of their hands relative to the keyboard, users will be able to type despite the obstruction caused by the head-mounted display (HMD). The viability of this approach was tested and the tool released as a plugin for the Unity development platform. The potential uses for the plugin go beyond text entry, and the project can be expanded to include many physical input devices.

This dissertation examines the developments and progress of spatial calibration procedures for Optical See-Through (OST) Head-Mounted Display (HMD) devices for visual Augmented Reality (AR) applications. Rapid developments in commercial AR systems have created an explosion of OST device options for not only research and industrial purposes, but also the consumer market as well. This expansion in hardware availability is equally matched by a need for intuitive standardized calibration procedures that are not only easily completed by novice users, but which are also readily applicable across the largest range of hardware options. This demand for robust uniform calibration schemes is the driving motive behind the original contributions offered within this work. A review of prior surveys and canonical description for AR and OST display developments is provided before narrowing the contextual scope to the research questions evolving within the calibration domain. Both established and state of the art calibration techniques and their general implementations are explored, along with prior user study assessments and the prevailing evaluation metrics and practices employed within. The original contributions begin with a user study evaluation comparing and contrasting the accuracy and precision of an established manual calibration method against a state of the art semi-automatic technique. This is the first formal evaluation of any non-manual approach and provides insight into the current usability limitations of present techniques and the complexities of next generation methods yet to be solved. The second study investigates the viability of a user-centric approach to OST HMD calibration through novel adaptation of manual calibration to consumer level hardware. Additional contributions describe the development of a complete demonstration application incorporating user-centric methods, a novel strategy for visualizing both calibration results and registration error from the user’s perspective, as well as a robust intuitive presentation style for binocular manual calibration. The final study provides further investigation into the accuracy differences observed between user-centric and environment-centric methodologies. The dissertation concludes with a summarization of the contribution outcomes and their impact on existing AR systems and research endeavors, as well as a short look ahead into future extensions and paths that continued calibration research should explore.

Head mounted projection display (HMPD) technology, as an alternative to conventional head mounted displays (HMD), offers a potential of designing wide field-of-view (FOV), low distortion optical see-through HMDs (OST-HMDs). Existing HMPD designs, however, suffer from problems of low luminance and low image resolution, which limits the applications of such information displays for the scenarios which require high luminance and high image fidelity. The design of a polarized head mounted projection display (p-HMPD) was recently proposed to overcome the challenge of low luminous efficiency in existing HMPD designs. Polarization management was employed to reduce the light loss caused by beamsplitting in an HMPD.The work in this dissertation focuses on the development and evaluation of an SXGA resolution, high efficiency p-HMPD system. The main contributions are as follows. First, the key elements in the polarization management scheme of a p-HMPD were selected and their polarization performances were characterized by measuring their Mueller matrices, based on which the overall display performance of a p-HMPD was analyzed.Second, based on a pair of ferroelectric liquid-crystal-on-silicon (FLCoS) microdisplays, a compact illumination unit and a light-weight projection system were designed, from which a p-HMPD prototype was built. Following the prototype implementation, a series of calibrations were performed to obtain correct color presentation, desired focusing setting, and optical system characteristics necessary for achieving accurate registration between virtual objects and their counterparts in the real world.Third, the imaging properties of a retroreflective screen which is an essential part of a p-HMPD or HMPD were studied and its effects on the image resolution of an HMPD system were further characterized.Finally, the performance of the system was evaluated through two objective user experiments, including a visual acuity assessment and a depth perception accuracy assessment.

Virtual Reality är ett media med gamla rötter, men samtidigt en ny teknologi för allmänheten. Ett av problemen med VR är att det kan frammana visst obehag då det brukas, så kallad simulatorsjuka (Kennedy m.fl., 1993), vilket forskare studerar i syftet att förstå hur det undviks. I denna undersökning har en artefakt tagits fram i form av en spelprototyp, av slaget 2,5D-side-scrollingspel till VR, och använts för att studera uppkomsten av simulatorsjuka. Artefakten använder en head-mounted display för att uppnå VR. Tre testpersoner deltog i undersökningen, och för att mäta symptomen användes ett beprövat frågeformulär samt kvalitativa intervjuer. Data visar på att en tidigare hypotes om intryckskonflikt (Kolasinski, 1995, s.7) är inkorrekt, samt att konventionella orienteringsmekaniker har vissa fördelar. För framtida studier bör simulatorsjuka undersökas från fler vinklar och/eller med ett större urval av testpersoner.

München, Techn. Univ., Diss., 2008

Over the last few years, there have been striking developments in wearable computing. Among all the different forms of wearable devices, Head Mounted Displays (HMDs) are deemed the first seamless solution to enabling workers with real time contextual information and allowing companies to integrate with existing back-end systems. The hands-free feature that come along with the HMDs is also believed a great advantage over many traditional technologies. However, few studies had discussed the impact of different design characteristics of head mounted displays on task performance. This study aimed to find out how different display positions of Head Mounted Displays may affect the performance of workers performing guided repair and maintenance tasks. A set of car maintenance tasks were performed by 20 participants with task guidance presented at four Display Conditions: above-eye HMD, eye-centered HMD, below-eye HMD and the traditional paper manual. Time and errors were measured and discussed, as well as other user experience related measurements.

Conventional stereoscopic displays present a pair of stereoscopic images on a single and fixed image plane. 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. Depth-fused multi-focal-plane display was proposed to create a fixed-viewpoint volumetric display capable of rendering correct or nearly-correct focus cues in a stereoscopic display through a small number of discretely placed focal planes. It effectively addresses the negative effects of conventional stereoscopic displays on depth perception accuracy and visual fatigue. In this dissertation, the fundamental design methods and considerations of depth-fused displays were refined and extended based on previous works and a high-resolution optical see-through multi-focal-plane head-mounted display enabled by state-of-the-art freeform optics was developed. The prototype system is capable of rendering nearly-correct focus cues for a large volume of 3D space extending into a depth range from 0 to 3 diopters at flicker-free speed. By incorporating freeform optics, the prototype not only achieves high quality imagery across a large 3D volume for the virtual display path but it also maintains better than 0.5 arcminutes visual resolution of the see-through view. The optical design, implementation and experimental validation of the display are presented and discussed in detail.

Zugl.: München, Techn. Univ., Diss., 2008

VR is a relatively new technology that has been shown to have potential to increase productivity andfacilitate better decision making, both within the architecture role and in the broader building industry. However, there are many difficulties that stand in the way of this new technology. In this study, the researcher uses semi-structured interviews to interview six working architects from threecities in Sweden. This is an attempt to investigate what architects think are the technical difficultiesthat stand in the way of VR use within the architect role. Both software and hardware limitations are investigated. I additionally investigate what architects think are potential solutions to those problems, and how architects think VR can be used in the future in a way that would be useful and facilitate better communication. This study found that, according to the architects interviewed, the technical limitations are mainly the lack of portability, isolation from the outside world, the need for powerful hardware, motion sickness, movement restrictions and the setup process being generally inconvenient. The future use of VR that would be useful according to the architects interviewed are the ability to have virtual meetings, VR being used in conjunction with AR, the ability to design and sketch in VR and using VR as a communication tool to convey design ideas to the public.