Management and Visualisation of Non-linear History of Polygonal 3D Models

The research presented in this thesis concerns the problems of maintenance and revision control of large-scale three dimensional (3D) models over the Internet. As the models grow in size and the authoring tools grow in complexity, standard approaches to collaborative asset development become impractical. The prevalent paradigm of sharing files on a file system poses serious risks with regards, but not limited to, ensuring consistency and concurrency of multi-user 3D editing. Although modifications might be tracked manually using naming conventions or automatically in a version control system (VCS), understanding the provenance of a large 3D dataset is hard due to revision metadata not being associated with the underlying scene structures. Some tools and protocols enable seamless synchronisation of file and directory changes in remote locations. However, the existing web-based technologies are not yet fully exploiting the modern design patters for access to and management of alternative shared resources online. Therefore, four distinct but highly interconnected conceptual tools are explored. The first is the organisation of 3D assets within recent document-oriented No Structured Query Language (NoSQL) databases. These "schemaless" databases, unlike their relational counterparts, do not represent data in rigid table structures. Instead, they rely on polymorphic documents composed of key-value pairs that are much better suited to the diverse nature of 3D assets. Hence, a domain-specific non-linear revision control system 3D Repo is built around a NoSQL database to enable asynchronous editing similar to traditional VCSs. The second concept is that of visual 3D differencing and merging. The accompanying 3D Diff tool supports interactive conflict resolution at the level of scene graph nodes that are de facto the delta changes stored in the repository. The third is the utilisation of HyperText Transfer Protocol (HTTP) for the purposes of 3D data management. The XML3DRepo daemon application exposes the contents of the repository and the version control logic in a Representational State Transfer (REST) style of architecture. At the same time, it manifests the effects of various 3D encoding strategies on the file sizes and download times in modern web browsers. The fourth and final concept is the reverse-engineering of an editing history. Even if the models are being version controlled, the extracted provenance is limited to additions, deletions and modifications. The 3D Timeline tool, therefore, implies a plausible history of common modelling operations such as duplications, transformations, etc. Given a collection of 3D models, it estimates a part-based correspondence and visualises it in a temporal flow. The prototype tools developed as part of the research were evaluated in pilot user studies that suggest they are usable by the end users and well suited to their respective tasks. Together, the results constitute a novel framework that demonstrates the feasibility of a domain-specific 3D version control

Technological framework for ubiquitous interactions using context–aware mobile devices

This report presents research and development of dedicated system architecture, designed to enable its users to interact with each other as well as to access information on Points of Interest that exist in their immediate environment. This is accomplished through managing personal preferences and contextual information in a distributed manner and in real-time. The advantage of this system architecture is that it uses mobile devices, heterogeneous sensors and a selection of user interface paradigms to produce a sociotechnical framework to enhance the perception of the environment and promote intuitive interactions. The thrust of the work has been on software development and component integration. Iterative prototyping was adopted as a development method in order to effectively implement the users’ feedback and establish a platform for collaboration that closely meets the requirements and aids their decision-making process. The requirement acquisition was followed by the system-modelling phase in order to produce a robust software prototype. The implementation includes component-based development and extensive use of design patterns over native programming. Conclusively, the software product has become the means to evaluate differences in the use of mixed reality technologies in a ubiquitous scenario. The prototype can query a number of context sources such as sensors, or details of the personal profile, to acquire relevant data. The data (and metadata) is stored in opensource structures, so that they are accessible at every layer of the system architecture and at any time. By proactively processing the acquired context, the system can assist the users in their tasks (e.g. navigation) without explicit input – e.g. by simply creating a gesture with the device. However, advanced interaction with the application via the user interface is available for requests that are more complex. Representations of the real world objects, their spatial relations and other captured features of interest are visualised on scalable interfaces, ranging from 2D to 3D models and from photorealism to stylised clues and symbols. Two principal modes of operation have been implemented; one, using geo-referenced virtual reality models of the environment, updated in real time, and second, using the overlay of descriptive annotations and graphics on the video images of the surroundings, captured by a video camera. The latter is referred to as augmented reality. The continuous feed of the device position and orientation data, from the GPS receiver and the digital compass, into the application, makes the framework fit for use in unknown environments and therefore suitable for ubiquitous operation. This is one of the novelties of the proposed framework, because it enables a whole range of social, peer-to-peer interactions to take place. The scenarios of how the system could be employed to pursue these remote interactions and collaborative efforts on mobile devices are addressed in the context of urban navigation. The conceptual design and implementation of the novel location and orientation based algorithm for mobile AR are presented in detail. The system is, however, multifaceted and capable of supporting peer-to-peer exchange of information in a pervasive fashion, usable in various contexts. The modalities of these interactions are explored and laid out in several scenarios, but particularly in the context of user adoption. Two evaluation tasks took place. The preliminary evaluation examined certain aspects that influence user interaction while being immersed in a virtual environment, whereas the second summative evaluation compared the utility and certain usability aspects of the AR and VR interfaces

Parametric BIM-based Design Review

This research addressed the need for a new design review technology and method to express the tangible and intangible qualities of architectural experience of parametric BIM-based design projects. The research produced an innovative presentation tool by which parametric design is presented systematically. Focus groups provided assessments of the tool to reveal the usefulness of a parametric BIM-based design review method. The way in which we visualize architecture affects the way we design and perceive architectural form and performance. Contemporary architectural forms and systems are very complex, yet most architects who use Building Information Modeling (BIM) and generative design methods still embrace the two-dimensional 15th-century Albertian representational methods to express and review design projects. However, architecture cannot be fully perceived through a set of drawings that mediate our perception and evaluation of the built environment. The systematic and conventional approach of traditional architectural representation, in paper-based and slide-based design reviews, is not able to visualize phenomenal experience nor the inherent variation and versioning of parametric models. Pre-recorded walk-throughs with high quality rendering and imaging have been in use for decades, but high verisimilitude interactive walk-throughs are not commonly used in architectural presentations. The new generations of parametric and BIM systems allow for the quick production of variations in design by varying design parameters and their relationships. However, there is a lack of tools capable of conducting design reviews that engage the advantages of parametric and BIM design projects. Given the multitude of possibilities of in-game interface design, game-engines provide an opportunity for the creation of an interactive, parametric, and performance-oriented experience of architectural projects with multi-design options. This research has produced a concept for a dynamic presentation and review tool and method intended to meet the needs of parametric design, performance-based evaluation, and optimization of multi-objective design options. The concept is illustrated and tested using a prototype (Parametric Design Review, or PDR) based upon an interactive gaming environment equipped with a novel user interface that simultaneously engages the parametric framework, object parameters, multi-objective optimized design options and their performances with diagrammatic, perspectival, and orthographic representations. The prototype was presented to representative users in multiple focus group sessions. Focus group discussion data reveal that the proposed PDR interface was perceived to be useful if used for design reviews in both academic and professional practice settings

An Information-Theoretic Framework for Consistency Maintenance in Distributed Interactive Applications

Distributed Interactive Applications (DIAs) enable geographically dispersed users to interact with each other in a virtual environment. A key factor to the success of a DIA is the maintenance of a consistent view of the shared virtual world for all the participants. However, maintaining consistent states in DIAs is difficult under real networks. State changes communicated by messages over such networks suffer latency leading to inconsistency across the application. Predictive Contract Mechanisms (PCMs) combat this problem through reducing the number of messages transmitted in return for perceptually tolerable inconsistency. This thesis examines the operation of PCMs using concepts and methods derived from information theory. This information theory perspective results in a novel information model of PCMs that quantifies and analyzes the efficiency of such methods in communicating the reduced state information, and a new adaptive multiple-model-based framework for improving consistency in DIAs. The first part of this thesis introduces information measurements of user behavior in DIAs and formalizes the information model for PCM operation. In presenting the information model, the statistical dependence in the entity state, which makes using extrapolation models to predict future user behavior possible, is evaluated. The efficiency of a PCM to exploit such predictability to reduce the amount of network resources required to maintain consistency is also investigated. It is demonstrated that from the information theory perspective, PCMs can be interpreted as a form of information reduction and compression. The second part of this thesis proposes an Information-Based Dynamic Extrapolation Model for dynamically selecting between extrapolation algorithms based on information evaluation and inferred network conditions. This model adapts PCM configurations to both user behavior and network conditions, and makes the most information-efficient use of the available network resources. In doing so, it improves PCM performance and consistency in DIAs

開放型3 次元共生空間の構成に関する研究

Tohoku University白鳥 則郎課

Visualising software in cyberspace

The problems of maintaining software systems are well documented. The increasing size and complexity of modern software serves only to worsen matters. Software maintainers are typically confronted with very large and very complex software systems, of which they may have little or no prior knowledge. At this stage they will normally have some maintenance task to perform, though possibly little indication of where or how to start. They need to investigate and understand the software to some extent in order to begin maintenance. This understanding process is termed program comprehension. There are various theories on program comprehension, many of which put emphasis on the construction of a mental model of the software within the mind of the maintainor. These same theories hypothesise a number of techniques employed by the maintainer for the creation and revision of this mental model. Software visualisation attempts to provide tool support for generating, supplementing and verifying the maintainer’s mental model. The majority of software visualisations to date have concentrated on producing two dimensional representations and animations of various aspects of a software system. Very little work has been performed previously regarding the issues involved in visualising software within a virtual reality environment. This research represents a significant first step into this exciting field and offers insight into the problems posed by this new media. This thesis provides an identification of the possibilities afforded byU3D graphics for software visualisation and program comprehension. It begins by defining seven key areas of 3D software visualisation, followed by the definition of two terms, visualisation and representation. These two terms provide a conceptual division between a visualisation and the elements of which it is comprised. This division enables improved discussion of the properties of a 3D visualisation and particularly the idenfification of properties that are desirable for a successful visualisation. A number of such desirable properties are suggested for both visualisations and representations, providing support for the design and evaluation of a 3D software visualisation system. Also presented are a number of prototype visualisations, each providing a different approach to the visualisation of a software system. The prototypes help demonstrate the practicalities and feasibility of 3D software visualisation. Evaluation of these prototypes is performed using a variety of techniques, the results of which emphasise the fact that there is substantial potential for the application of 3D graphics and virtual reality to software visualisation

Presence 2005: the eighth annual international workshop on presence, 21-23 September, 2005 University College London (Conference proceedings)

OVERVIEW (taken from the CALL FOR PAPERS) Academics and practitioners with an interest in the concept of (tele)presence are invited to submit their work for presentation at PRESENCE 2005 at University College London in London, England, September 21-23, 2005. The eighth in a series of highly successful international workshops, PRESENCE 2005 will provide an open discussion forum to share ideas regarding concepts and theories, measurement techniques, technology, and applications related to presence, the psychological state or subjective perception in which a person fails to accurately and completely acknowledge the role of technology in an experience, including the sense of 'being there' experienced by users of advanced media such as virtual reality. The concept of presence in virtual environments has been around for at least 15 years, and the earlier idea of telepresence at least since Minsky's seminal paper in 1980. Recently there has been a burst of funded research activity in this area for the first time with the European FET Presence Research initiative. What do we really know about presence and its determinants? How can presence be successfully delivered with today's technology? This conference invites papers that are based on empirical results from studies of presence and related issues and/or which contribute to the technology for the delivery of presence. Papers that make substantial advances in theoretical understanding of presence are also welcome. The interest is not solely in virtual environments but in mixed reality environments. Submissions will be reviewed more rigorously than in previous conferences. High quality papers are therefore sought which make substantial contributions to the field. Approximately 20 papers will be selected for two successive special issues for the journal Presence: Teleoperators and Virtual Environments. PRESENCE 2005 takes place in London and is hosted by University College London. The conference is organized by ISPR, the International Society for Presence Research and is supported by the European Commission's FET Presence Research Initiative through the Presencia and IST OMNIPRES projects and by University College London

Proceedings of the 9th international conference on disability, virtual reality and associated technologies (ICDVRAT 2012)

The proceedings of the conferenc