3D (embodied) projection mapping and sensing bodies : a study in interactive dance performance

This dissertation identifies the synergies between physical and virtual environments when designing for immersive experiences in interactive dance performances. The integration of virtual information in physical space is transforming our interactions and experiences with the world. By using the body and creative expression as the interface between real and virtual worlds, dance performance creates a privileged framework to research and design interactive mixed reality environments and immersive augmented architectures. The research is primarily situated in the fields of visual art and interaction design. It combines performance with transdisciplinary fields and intertwines practice with theory. The theoretical and conceptual implications involved in designing and experiencing immersive hybrid environments are analyzed using the reality–virtuality continuum. These theories helped frame the ways augmented reality architectures are achieved through the integration of dance performance with digital software and reception displays. They also helped identify the main artistic affordances and restrictions in the design of augmented reality and augmented virtuality environments for live performance. These pervasive media architectures were materialized in three field experiments, the live dance performances. Each performance was created in three different stages of conception, design and production. The first stage was to “digitize” the performer’s movement and brain activity to the virtual environment and our system. This was accomplished through the use of depth sensor cameras, 3D motion capture, and brain computer interfaces. The second stage was the creation of the computational architecture and software that aggregates the connections and mapping between the physical body and the spatial dynamics of the virtual environment. This process created real-time interactions between the performer’s behavior and motion and the real-time generative computer 3D graphics. Finally, the third stage consisted of the output modality: 3D projector based augmentation techniques were adopted in order to overlay the virtual environment onto physical space. This thesis proposes and lays out theoretical, technical, and artistic frameworks between 3D digital environments and moving bodies in dance performance. By sensing the body and the brain with the 3D virtual environments, new layers of augmentation and interactions are established, and ultimately this generates mixed reality environments for embodied improvisational self-expression.Radio-Television-Fil

Advances in Spatially Faithful (3D) Telepresence

Benefits of AR technologies have been well proven in collaborative industrial applications, for example in remote maintenance and consultancy. Benefits may also be high in telepresence applications, where virtual and mixed reality (nowadays often referred as extended reality, XR) technologies are used for sharing information or objects over network. Since the 90’s, technical enablers for advanced telepresence solutions have developed considerably. At the same time, the importance of remote technologies has grown immensely due to general disruption of work, demands for reducing travelling and CO2, and the need for preventing pandemics. An advanced 3D telepresence solution benefits from using XR technologies. Particularly interesting are solutions based on HMD or glasses type of near-eye-displays (NED). However, as AR/VR glasses supporting natural occlusions and accommodation are still missing from the market, a good alternative is to use screen displays in new ways, better supporting e.g. virtual meeting geometries and other important cues for 3D perception. In this article, researchers Seppo Valli, Mika Hakkarainen, and Pekka Siltanen from VTT Technical Research Centre of Finland describe the status, challenges, and opportunities in both glasses and screen based 3D telepresence. The writers also specify an affordable screen based solution with improved immersiveness, naturalness, and efficiency, enhanced by applying XR technologies

Towards System Agnostic Calibration of Optical See-Through Head-Mounted Displays for Augmented Reality

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

SPATIO-TEMPORAL REGISTRATION IN AUGMENTED REALITY

The overarching goal of Augmented Reality (AR) is to provide users with the illusion that virtual and real objects coexist indistinguishably in the same space. An effective persistent illusion requires accurate registration between the real and the virtual objects, registration that is spatially and temporally coherent. However, visible misregistration can be caused by many inherent error sources, such as errors in calibration, tracking, and modeling, and system delay. This dissertation focuses on new methods that could be considered part of "the last mile" of spatio-temporal registration in AR: closed-loop spatial registration and low-latency temporal registration: 1. For spatial registration, the primary insight is that calibration, tracking and modeling are means to an end---the ultimate goal is registration. In this spirit I present a novel pixel-wise closed-loop registration approach that can automatically minimize registration errors using a reference model comprised of the real scene model and the desired virtual augmentations. Registration errors are minimized in both global world space via camera pose refinement, and local screen space via pixel-wise adjustments. This approach is presented in the context of Video See-Through AR (VST-AR) and projector-based Spatial AR (SAR), where registration results are measurable using a commodity color camera. 2. For temporal registration, the primary insight is that the real-virtual relationships are evolving throughout the tracking, rendering, scanout, and display steps, and registration can be improved by leveraging fine-grained processing and display mechanisms. In this spirit I introduce a general end-to-end system pipeline with low latency, and propose an algorithm for minimizing latency in displays (DLP DMD projectors in particular). This approach is presented in the context of Optical See-Through AR (OST-AR), where system delay is the most detrimental source of error. I also discuss future steps that may further improve spatio-temporal registration. Particularly, I discuss possibilities for using custom virtual or physical-virtual fiducials for closed-loop registration in SAR. The custom fiducials can be designed to elicit desirable optical signals that directly indicate any error in the relative pose between the physical and projected virtual objects.Doctor of Philosoph

Augmented Reality in Minimally Invasive Surgery

In the last 15 years Minimally Invasive Surgery, with techniques such as laparoscopy or endoscopy, has become very important and research in this field is increasing since these techniques provide the surgeons with less invasive means of reaching the patient’s internal anatomy and allow for entire procedures to be performed with only minimal trauma to the patient. The advantages of the use of this surgical method are evident for patients because the possible trauma is reduced, postoperative recovery is generally faster and there is less scarring. Despite the improvement in outcomes, indirect access to the operation area causes restricted vision, difficulty in hand-eye coordination, limited mobility handling instruments, two-dimensional imagery with a lack of detailed information and a limited visual field during the whole operation. The use of the emerging Augmented Reality technology shows the way forward by bringing the advantages of direct visualization (which you have in open surgery) back to minimally invasive surgery and increasing the physician's view of his surroundings with information gathered from patient medical images. Augmented Reality can avoid some drawbacks of Minimally Invasive Surgery and can provide opportunities for new medical treatments. After two decades of research into medical Augmented Reality, this technology is now advanced enough to meet the basic requirements for a large number of medical applications and it is feasible that medical AR applications will be accepted by physicians in order to evaluate their use and integration into the clinical workflow. Before seeing the systematic use of these technologies as support for minimally invasive surgery some improvements are still necessary in order to fully satisfy the requirements of operating physicians

Mobile Augmented Reality: User Interfaces, Frameworks, and Intelligence

Mobile Augmented Reality (MAR) integrates computer-generated virtual objects with physical environments for mobile devices. MAR systems enable users to interact with MAR devices, such as smartphones and head-worn wearables, and perform seamless transitions from the physical world to a mixed world with digital entities. These MAR systems support user experiences using MAR devices to provide universal access to digital content. Over the past 20 years, several MAR systems have been developed, however, the studies and design of MAR frameworks have not yet been systematically reviewed from the perspective of user-centric design. This article presents the first effort of surveying existing MAR frameworks (count: 37) and further discuss the latest studies on MAR through a top-down approach: (1) MAR applications; (2) MAR visualisation techniques adaptive to user mobility and contexts; (3) systematic evaluation of MAR frameworks, including supported platforms and corresponding features such as tracking, feature extraction, and sensing capabilities; and (4) underlying machine learning approaches supporting intelligent operations within MAR systems. Finally, we summarise the development of emerging research fields and the current state-of-the-art, and discuss the important open challenges and possible theoretical and technical directions. This survey aims to benefit both researchers and MAR system developers alike.Peer reviewe