David B. Arnold

Rendering of large and complex urban environments for real time heritage reconstructions

In this paper we describe a rendering package, which brings together a number of rendering techniques and optimisations to render large and complex urban environments at interactive frame rates. The package has been built on top of a proprietary Scene Graph structure developed for the CHARISMATIC project. The paper presents an integrated approach combining Real-time Optionally Adapting Meshes, View Frustum Culling, Occluder Shadows, Level of Detail for Houses and Motion Captured Avatars in a single application.We discuss the performance issues associated with our approaches and give comprehensive implementation details. We also consider implications of the trends in high performance graphics sub-systems for PCs in the context of data types and animations required for populated interactive virtual heritage experiences. Finally we present empirical results to demonstrate the importance of employing such techniques and the implications for practical virtual heritage applications.

Rapid procedural-modelling of architectural structures

This paper describes a range of procedural techniques being developed to allow historic building styles to be modelled in a rapid manner, suitable for extremely fast rendering. We are expecting these tools to be used to model large-scale urban virtual-environments, from ancient Rome to modern day Hong Kong.When creating large scenes, there are two particular problems that we need to address and overcome. Firstly, the need to model scenes efficiently leads to a sense of repetition of the models as a small number of individual models is used repeatedly. We believe that it is now feasible to avoid the sense of repetition by using models drawn from a large library of prototypes according to some well-defined tools. By using procedural modelling we hope to speed up the model-building process while providing a number of other benefits.The other problem with large scenes comes with rendering them at an acceptable frame rate. By incorporating our modellers with the scenegraph being used to render them, a series of techniques and attributes may be applied to the models to cull out geometry not visible to the viewer, and to provide smoother transitions between varying levels of detail, avoiding artefacts such as geometry popping.As well as describing how the approach can be used in particular applications we describe the architecture and implementation of the modelling tools. Finally we show how the approach can be extended to other architectural styles and the working environment customised.

Web based presentation of semantically tagged 3D content for public sculptures and monuments in the UK

The documentation and presentation of 3D digital content is a critical but non-trivial task for the Cultural Heritage sector. Curators are often faced with the task of cataloguing every piece of heritage and maintaining the resulting information in such a way which is suitable for scholarly research and public dissemination. Hence, the integration of 3D content poses additional challenges. This paper introduces research conducted to integrate semantically tagged 3D content to the catalogue acquired within the Public Monuments and Sculpture Associations National Recording Project (NRP) in the UK. This research involves the combination of graphical APIs and semantic technologies in order to integrate 3D content with semantic tags in a web browser. Although the initial results are still experimental; it is expected that they will support scholarly research and public dissemination by presenting a variety of integrated documentation on the project website: http://www.publicsculpturesofsussex.co.uk

Interactive storytelling and gaming environments for museums: the interactive storytelling exhibition project

Interactive storytelling and gaming technologies have great edutainment potential for engaging visitors with museum exhibitions. This paper presents the development and testing of the Interactive Storytelling Exhibition Project devised originally within the Factual and Learning Interactive Television Department of the British Broadcasting Corporation (BBC) and continued development at the University of Brighton. The project combines both interactive television storytelling and gaming technologies to immerse museum visitors with artefacts on exhibition, engaging the user into physical space using virtual stories.

Editorial for inaugural issue of JOCCH: Pasteur's Quadrant: Cultural heritage as inspiration for basic research in computer science

It’s not often that you get the chance to write the editorial to introduce a new Journal; in fact, for me this is a once-in-a-lifetime occasion. This issue of the ACM Journal on Computing and Cultural Heritage (JOCCH) is the culmination of about 5 years worth of aspiration, thought, and effort. The key to the journal’s mission is the intent to address interdisciplinary issues with innovative computing science and a solid perspective of the needs of cultural heritage professionals. In some cases these “needs” may not be appreciated by the vast majority of practicing heritage professionals since the potential applications they address may be beyond the immediate time horizons for adoption of technologies by the sector. This first issue of JOCCH is a special issue on Research Agendas which was called to allow those working at the interface of technology and Cultural Heritage to help formulate the range of topics that would set interesting challenges for high-quality research within the scope of the journal. The issue (and some articles that are expected to follow in future issues) are intended to help authors understand what is expected—the aspects of their research which would ideally fit the intended readership. I am regularly asked “how can there be any real computer science research in the applications of technology to heritage”? This extended editorial is intended to address the question and to analyze the nature of the research that I expect will demonstrate essential results for those working at this interface. In fact, the question is a wider one than just addressing the field of Cultural Heritage; the issues arise in any research field where basic research is undertaken which is known a priori will, if successful, impact on and be applied to another field. It is as much a question for the chemist undertaking basic research which is intended to find application in the field of drug design or the materials scientist who has specific engineering applications in mind when researching for materials with specific properties. This editorial is a synthesis drawn from two recent sources which it has been my privilege to author or co-author. The first is the paper presented at the Cultural Heritage stream of the Eurographics Conference in September 2007 [Arnold, 2007]. The second is the EPOCH Research Agenda for the Applications of ICTs to Cultural Heritage, which was completed in its 2nd edition in March 2008

Scene assembly for large scale urban reconstructions

Reconstructing large areas of historic cities involves assembling a scene from a combination of knowledge of areas that no longer exist and known monuments that have survived and can still be (at least partially) observed and measured. In many cases little detail is known for such areas although it can be anticipated that buildings in some specific generic styles would be typical of the time and place. At UEA considerable effort has been put into creating a Scene Assembler package for the CHARISMATIC project which brings together individually designed objects from detailed modelling packages such as 3DStudioMax and combines these with other more generic building prototypes. These objects are then laid out using a number of extremely powerful and user friendly operations within a landscape and sky dome. This process makes it easy and quick to put together a complete city scene, which is accurate enough, historically, to give a feel for what the area would have been like. The models constructed using the tools are intended to be used as backdrops for reconstructing historic populated events. This paper describes the stages in defining such models and the various tools available to speed up the process.

The Computer Graphics Virtual Device Interface

Decisions about which functions to include in systems like PHIGS and GKS-3D are based primarily on the tasks users want performed, such as direct support for 3D operations. The design criteria for device interface systems like the Computer Graphics Virtual Device Interface, however, must be based on what is feasible to do in a device, while still considering how to decompose tasks into hardware-realizable functions. Complicating these design decisions is the wide range of existing device technology and the breadth of usage models imposed by different task-oriented software.

Proposals for Configurable Models of Graphics Systems

During the early attempts in the late 1970’s to agree on the ‘standard’ effects of particular graphics users’ actions, many misunderstandings and problems occurred. These stemmed mainly from the use of common terms which, although having well defined meanings for all those discussing the effects, somehow produced serious discrepancies in allegedly equivalent systems192 These discrepancies were a direct result of differing models of the effects within the graphics system of apparently standard actions requested at the user interface, caused by the lack of a common underlying model of graphics system structure and operation and from poorly defined, or even undefined, graphics vocabulary and concepts.

Dual joints for 3D-structures

The increasing popularity of 3D printing is drawing the interest of the research community to the possibilities and challenges of this manufacturing method. Amongst its many uncertainties, we are concerned here with one of its certainties—that reduction of the material required in 3D printing is critical for efficiency and affordability. In this paper, we propose a solution to the computer graphics problem of, given a volume boundary, automatically defining the mesh of a low density internal structure that is 3D-printable. The proposed solution involves two steps. The first step is to define a cell complex partition for the internal space of a volume defined by its boundaries. The second step, is to apply the Skin4Skeleton algorithm, which uses the cell complex dual to produce a 3D-printable cell-complex mesh with a parametrised thickness.

Semantically rich 3D documentation for the preservation of tangible heritage

Traditionally, 3D acquisition technologies have been used to record heritage artefacts and to support specific tasks such as conservation or provenance verification. These exercises are usually a one-off as the technology and resources required are cost intensive. However, there is a recent impetus on the creation of 3D collections to document heritage artefacts which are semantically enriched by using annotations. A requirement of these solutions is the ability to support several representations of a heritage artefact recorded through time. This paper will propose an infrastructure to systematically enrich 3D shapes in a collection by using propagated annotations. In addition, it will describe the mechanisms for annotating, propagating and structuring the annotations using the CIDOC-CRM ontology. The results of this research have the potential to support heritage organisations in making their semantically rich 3D content available to a wider audience of professionals.