A Modular Approach to the Development of Interactive Augmented Reality Applications.

Augmented reality (AR) technologies are becoming increasingly popular as a result of the increase in the power of mobile computing devices. Emerging AR applications have the potential to have an enormous impact on industries such as education, healthcare, research, training and entertainment. There are currently a number of augmented reality toolkits and libraries available for the development of these applications; however, there is currently no standard tool for development. In this thesis we propose a modular approach to the organization and development of AR systems in order to enable the creation novel AR experiences. We also investigate the incorporation of the framework that resulted from our approach into game engines to enable the creation and visualization of immersive virtual reality experiences. We address issues in the development process of AR systems and provide a solution for reducing the time, cost and barrier of entry for development while simultaneously providing a framework in which researchers can test and apply advanced augmented reality technologies

Through the combining glass

Reflective optical combiners like beam splitters and two way mirrors are used in AR to overlap digital contents on the users' hands or bodies. Augmentations are usually unidirectional, either reflecting virtual contents on the user's body (Situated Augmented Reality) or augmenting user's reflections with digital contents (AR mirrors). But many other novel possibilities remain unexplored. For example, users' hands, reflected inside a museum AR cabinet, can allow visitors to interact with the artifacts exhibited. Projecting on the user's hands as their reflection cuts through the objects can be used to reveal objects' internals. Augmentations from both sides are blended by the combiner, so they are consistently seen by any number of users, independently of their location or, even, the side of the combiner through which they are looking. This paper explores the potential of optical combiners to merge the space in front and behind them. We present this design space, identify novel augmentations/interaction opportunities and explore the design space using three prototypes

On Inter-referential Awareness in Collaborative Augmented Reality

For successful collaboration to occur, a workspace must support inter-referential awareness - or the ability for one participant to refer to a set of artifacts in the environment, and for that reference to be correctly interpreted by others. While referring to objects in our everyday environment is a straight-forward task, the non-tangible nature of digital artifacts presents us with new interaction challenges. Augmented reality (AR) is inextricably linked to the physical world, and it is natural to believe that the re-integration of physical artifacts into the workspace makes referencing tasks easier; however, we find that these environments combine the referencing challenges from several computing disciplines, which compound across scenarios. This dissertation presents our studies of this form of awareness in collaborative AR environments. It stems from our research in developing mixed reality environments for molecular modeling, where we explored spatial and multi-modal referencing techniques. To encapsulate the myriad of factors found in collaborative AR, we present a generic, theoretical framework and apply it to analyze this domain. Because referencing is a very human-centric activity, we present the results of an exploratory study which examines the behaviors of participants and how they generate references to physical and virtual content in co-located and remote scenarios; we found that participants refer to content using physical and virtual techniques, and that shared video is highly effective in disambiguating references in remote environments. By implementing user feedback from this study, a follow-up study explores how the environment can passively support referencing, where we discovered the role that virtual referencing plays during collaboration. A third study was conducted in order to better understand the effectiveness of giving and interpreting references using a virtual pointer; the results suggest the need for participants to be parallel with the arrow vector (strengthening the argument for shared viewpoints), as well as the importance of shadows in non-stereoscopic environments. Our contributions include a framework for analyzing the domain of inter-referential awareness, the development of novel referencing techniques, the presentation and analysis of our findings from multiple user studies, and a set of guidelines to help designers support this form of awareness

Real-time Illumination and Visual Coherence for Photorealistic Augmented/Mixed Reality

A realistically inserted virtual object in the real-time physical environment is a desirable feature in augmented reality (AR) applications and mixed reality (MR) in general. This problem is considered a vital research area in computer graphics, a field that is experiencing ongoing discovery. The algorithms and methods used to obtain dynamic and real-time illumination measurement, estimating, and rendering of augmented reality scenes are utilized in many applications to achieve a realistic perception by humans. We cannot deny the powerful impact of the continuous development of computer vision and machine learning techniques accompanied by the original computer graphics and image processing methods to provide a significant range of novel AR/MR techniques. These techniques include methods for light source acquisition through image-based lighting or sampling, registering and estimating the lighting conditions, and composition of global illumination. In this review, we discussed the pipeline stages with the details elaborated about the methods and techniques that contributed to the development of providing a photo-realistic rendering, visual coherence, and interactive real-time illumination results in AR/MR

A comprehensive taxonomy for three-dimensional displays

Even though three-dimensional (3D) displays have been introduced in relatively recent times in the context of display technology, they have undergone a rapid evolution, to the point that a plethora of equipment able to reproduce dynamic three-dimensional scenes in real time is now becoming commonplace in the consumer market. This paper’s main contributions are (1) a clear definition of a 3D display, based on the visual depth cues supported, and (2) a hierarchical taxonomy of classes and subclasses of 3D displays, based on a set of properties that allows an unambiguous and systematic classification scheme for three-dimensional displays. Five main types of 3D displays are thus defined –two of those new–, aiming to provide a taxonomy that is largely backwards-compatible, but that also clarifies prior inconsistencies in the literature. This well-defined outline should also enable exploration of the 3D display space and devising of new 3D display systems.Fundação para a Ciência e Tecnologi

Toward New Ecologies of Cyberphysical Representational Forms, Scales, and Modalities

Research on tangible user interfaces commonly focuses on tangible interfaces acting alone or in comparison with screen-based multi-touch or graphical interfaces. In contrast, hybrid approaches can be seen as the norm for established mainstream interaction paradigms. This dissertation describes interfaces that support complementary information mediations, representational forms, and scales toward an ecology of systems embodying hybrid interaction modalities. I investigate systems combining tangible and multi-touch, as well as systems combining tangible and virtual reality interaction. For each of them, I describe work focusing on design and fabrication aspects, as well as work focusing on reproducibility, engagement, legibility, and perception aspects

A Virtual Assistant on Campus for Blind and Low Vision Students

I want to make the most of my college experience…pass the courses I need to get into law school, make new friends, and travel. Maybe study abroad. These are the sentiments of one undergraduate student. These goals are not so different from those of hundreds of students attending college, yet, the mere fact she is blind creates a completely different perspective. This exploratory study seeks to learn how undergraduate students who are blind or have low vision (BLV), experience Aira, an augmented reality application, as a visual interpreter, in post-secondary settings. Semi-structured interviews illuminated three major themes: (a) accessibility impacts productivity, (b) incidental learning affects social interactions, and (c) sense of self. Theoretical conclusions are made on how Aira positively contributes to a complete college experience for students who are BLV, as outlined in the Seven Vectors of Identification Development (Chickering & Reisser, 1993)

Towards a framework for investigating tangible environments for learning

External representations have been shown to play a key role in mediating cognition. Tangible environments offer the opportunity for novel representational formats and combinations, potentially increasing representational power for supporting learning. However, we currently know little about the specific learning benefits of tangible environments, and have no established framework within which to analyse the ways that external representations work in tangible environments to support learning. Taking external representation as the central focus, this paper proposes a framework for investigating the effect of tangible technologies on interaction and cognition. Key artefact-action-representation relationships are identified, and classified to form a structure for investigating the differential cognitive effects of these features. An example scenario from our current research is presented to illustrate how the framework can be used as a method for investigating the effectiveness of differential designs for supporting science learning