Proposed Enhancements to the X3D Geospatial Component

Web3D '09: Proceedings of the 14th International Conference on 3D Web Technology, June 2009, Pages 155–158.The article of record as published may be found at https://doi.org/10.1145/1559764.1559788The Geospatial Component of the X3D Standard suffers from some deficiencies that prevent its wider adoption. This paper addresses two of these deficiencies. The first problem is that in order to reduce spatial jitter content must be built with regionally defined GeoOrigin nodes. This approach is fine for localized regional geospatial data visualization requirements, but fails for accurately viewing data in a global context or for combining content with different GeoOrigins. The second problem is the limited options for providing terrain data to the browser for rendering. The GeoLOD node is not the optimal solution for allowing the X3D browser to render terrain data in a high performing manner. This paper presents solutions to these problems for consideration by the Web3D community

X3D Earth Terrain-Tile Production Chain for Georeferenced Simulation

Web3D '09: Proceedings of the 14th International Conference on 3D Web Technology, June 2009, Pages 159–166.The article of record as published may be found at https://doi.org/10.1145/1559764.1559789Broad needs for digital models of real environments such as 3D terrain or cyber cities are increasing. Many applications related to modeling and simulation require virtual environments constructed from real-world geospatial information in order to guarantee relevance and accuracy in the simulation. The most fundamental data for building virtual environments, terrain elevation and orthogonal imagery, is typically acquired using optical sensors mounted on satellites or airplanes. Providing interoperable and reusable digital models in 3D is important for promoting practical applications of high-resolution airborne imagery. This paper presents research results regarding virtual-environment representations of geospatial information, especially for 3D shape and appearance of virtual terrain. It describes a framework for constructing real-time 3D models of large terrain based on highresolution satellite imagery. This approach is also suitable for underwater bathymetry. The Extensible 3D Graphics (X3D) Geospatial Component standard is applied to produce X3D Earth models with global scope. Efficient rendering, network retrieval and data caching/removal must all be optimized simultaneously, across servers, networks and clients, in order to accomplish these goals properly. Details of this standard-based approach for providing an infrastructure for real-time 3D simulation merging high-resolution geometry and imagery are also presented. This work facilitates open interchange and interoperability across diverse simulation systems and is independently usable by governments, industry, scientists and the general public

Ubiquitous volume rendering in the web platform

176 p.The main thesis hypothesis is that ubiquitous volume rendering can be achieved using WebGL. The thesis enumerates the challenges that should be met to achieve that goal. The results allow web content developers the integration of interactive volume rendering within standard HTML5 web pages. Content developers only need to declare the X3D nodes that provide the rendering characteristics they desire. In contrast to the systems that provide specific GPU programs, the presented architecture creates automatically the GPU code required by the WebGL graphics pipeline. This code is generated directly from the X3D nodes declared in the virtual scene. Therefore, content developers do not need to know about the GPU.The thesis extends previous research on web compatible volume data structures for WebGL, ray-casting hybrid surface and volumetric rendering, progressive volume rendering and some specific problems related to the visualization of medical datasets. Finally, the thesis contributes to the X3D standard with some proposals to extend and improve the volume rendering component. The proposals are in an advance stage towards their acceptance by the Web3D Consortium

Ubiquitous volume rendering in the web platform

176 p.The main thesis hypothesis is that ubiquitous volume rendering can be achieved using WebGL. The thesis enumerates the challenges that should be met to achieve that goal. The results allow web content developers the integration of interactive volume rendering within standard HTML5 web pages. Content developers only need to declare the X3D nodes that provide the rendering characteristics they desire. In contrast to the systems that provide specific GPU programs, the presented architecture creates automatically the GPU code required by the WebGL graphics pipeline. This code is generated directly from the X3D nodes declared in the virtual scene. Therefore, content developers do not need to know about the GPU.The thesis extends previous research on web compatible volume data structures for WebGL, ray-casting hybrid surface and volumetric rendering, progressive volume rendering and some specific problems related to the visualization of medical datasets. Finally, the thesis contributes to the X3D standard with some proposals to extend and improve the volume rendering component. The proposals are in an advance stage towards their acceptance by the Web3D Consortium

Documenting and validating Virtual Archaeology

The use of Virtual Archaeology is expanding rapidly, not only in the museum and archaeology professions, but also in the broadcast media, tourism and heritage industries. Many concerns have been expressed about the lack of transparency and difficulty in validating the models and presentations used in these contexts. A case study is used to illustrate the role of metadata in addressing these problems. The paper argues that appropriate metadata documentation of projects may extend the critical apparatus that we take for granted in scientific papers into the world of distributed Virtual Archaeology. Three recently introduced XML languages for multimedia (SMIL), vector graphics (SVG) and virtual reality (X3D) applications are examined with particular reference to their metadata hosting capabilities. Finally, an outline proposal for a Virtual Archaeology Metadata Profile and Schema is presented, based on refinements of the Dublin Core and other metadata schemas

Rapid Prototyping for Virtual Environments

Development of Virtual Environment (VE) applications is challenging where application developers are required to have expertise in the target VE technologies along with the problem domain expertise. New VE technologies impose a significant learning curve to even the most experienced VE developer. The proposed solution relies on synthesis to automate the migration of a VE application to a new unfamiliar VE platform/technology. To solve the problem, the Common Scene Definition Framework (CSDF) is developed, that serves as a superset/model representation of the target virtual world. Input modules are developed to populate the framework with the capabilities of the virtual world imported from VRML 2.0 and X3D formats. The synthesis capability is built into the framework to synthesize the virtual world into a subset of VRML 2.0, VRML 1.0, X3D, Java3D, JavaFX, JavaME, and OpenGL technologies, which may reside on different platforms. Interfaces are designed to keep the framework extensible to different and new VE formats/technologies. The framework demonstrated the ability to quickly synthesize a working prototype of the input virtual environment in different VE formats

3D Spatial Data Infrastructures for web-based Visualization

In this thesis, concepts for developing Spatial Data Infrastructures with an emphasis on visualizing 3D landscape and city models in distributed environments are discussed. Spatial Data Infrastructures are important for public authorities in order to perform tasks on a daily basis, and serve as research topic in geo-informatics. Joint initiatives at national and international level exist for harmonizing procedures and technologies. Interoperability is an important aspect in this context - as enabling technology for sharing, distributing, and connecting geospatial data and services. The Open Geospatial Consortium is the main driver for developing international standards in this sector and includes government agencies, universities and private companies in a consensus process. 3D city models are becoming increasingly popular not only in desktop Virtual Reality applications but also for being used in professional purposes by public authorities. Spatial Data Infrastructures focus so far on the storage and exchange of 3D building and elevation data. For efficient streaming and visualization of spatial 3D data in distributed network environments such as the internet, concepts from the area of real time 3D Computer Graphics must be applied and combined with Geographic Information Systems (GIS). For example, scene graph data structures are commonly used for creating complex and dynamic 3D environments for computer games and Virtual Reality applications, but have not been introduced in GIS so far. In this thesis, several aspects of how to create interoperable and service-based environments for 3D spatial data are addressed. These aspects are covered by publications in journals and conference proceedings. The introductory chapter provides a logic succession from geometrical operations for processing raw data, to data integration patterns, to system designs of single components, to service interface descriptions and workflows, and finally to an architecture of a complete distributed service network. Digital Elevation Models are very important in 3D geo-visualization systems. Data structures, methods and processes are described for making them available in service based infrastructures. A specific mesh reduction method is used for generating lower levels of detail from very large point data sets. An integration technique is presented that allows the combination with 2D GIS data such as roads and land use areas. This approach allows using another optimization technique that greatly improves the usability for immersive 3D applications such as pedestrian navigation: flattening road and water surfaces. It is a geometric operation, which uses data structures and algorithms found in numerical simulation software implementing Finite Element Methods. 3D Routing is presented as a typical application scenario for detailed 3D city models. Specific problems such as bridges, overpasses and multilevel networks are addressed and possible solutions described. The integration of routing capabilities in service infrastructures can be accomplished with standards of the Open Geospatial Consortium. An additional service is described for creating 3D networks and for generating 3D routes on the fly. Visualization of indoor routes requires different representation techniques. As server interface for providing access to all 3D data, the Web 3D Service has been used and further developed. Integrating and handling scene graph data is described in order to create rich virtual environments. Coordinate transformations of scene graphs are described in detail, which is an important aspect for ensuring interoperability between systems using different spatial reference systems. The Web 3D Service plays a central part in nearly all experiments that have been carried out. It does not only provide the means for interactive web-visualizations, but also for performing further analyses, accessing detailed feature information, and for automatic content discovery. OpenStreetMap and other worldwide available datasets are used for developing a complete architecture demonstrating the scalability of 3D Spatial Data Infrastructures. Its suitability for creating 3D city models is analyzed, according to requirements set by international standards. A full virtual globe system has been developed based on OpenStreetMap including data processing, database storage, web streaming and a visualization client. Results are discussed and compared to similar approaches within geo-informatics research, clarifying in which application scenarios and under which requirements the approaches in this thesis can be applied

JSB Composability and Web Services Interoperability Via Extensible Modeling & Simulation Framework (XMSF), Model Driven Architecture (MDA), Component Repositories, and Web-based Visualization

Study Report prepared for the U. S. Air Force, Joint Synthetic Battlespace Analysis of Technical Approaches (ATA) Studies & Prototyping Overview: This paper summarizes research work conducted by organizations concerned with interoperable distributed information technology (IT) applications, in particular the Naval Postgraduate School (NPS) and Old Dominion University (ODU). Although the application focus is distributed modeling & simulation (M&S) the results and findings are in general easily applicable to other distributed concepts as well, in particular the support of operations by M&S applications, such as distributed mission operations. The core idea of this work is to show the necessity of applying open standards for component description, implementation, and integration accompanied by aligned management processes and procedures to enable continuous interoperability for legacy and new M&S components of the live, virtual, and constructive domain within the USAF Joint Synthetic Battlespace (JSB). JSB will be a common integration framework capable of supporting the future emerging simulation needs ranging from training and battlefield rehearsal to research, system development and acquisition in alignment with other operational requirements, such as integration of command and control, support of operations, integration of training ranges comprising real systems, etc. To this end, the study describes multiple complementary Integrated Architecture Framework approaches and shows, how the various parts must be orchestrated in order to support the vision of JSB effectively and efficiently. Topics of direct relevance include Web Services via Extensible Modeling & Simulation Framework (XMSF), the Object Management Group (OMG)’s Model Driven Architecture (MDA), XML-based resource repositories, and Web-based X3D visualization. To this end, the report shows how JSB can − Utilize Web Services throughout all components via XMSF methodologies, − Compose diverse system visualizations using Web-based X3D graphics, − Benefit from distributed modeling methods using MDA, and − Best employ resource repositories for broad and consistent composability. Furthermore, the report recommends the establishment of necessary management organizations responsible for the necessary alignment of management processes and procedures within the JSB as well as with neighbored domains. Continuous interoperability cannot be accomplished by technical standards alone. The application of technical standards targets the implementation level of the system of systems, which results in an interoperable solution valid only for the actual 2 implementation. To insure continuity, the influence of updates, upgrades and introduction of components on the system of systems must be captured in the project management procedures of the participating systems. Finally, the report proposes an exemplifying set of proof-of-capability demonstration prototypes and a five-year technical/institutional transformation plan. All key references are online available at http://www.movesinstitute.org/xmsf/xmsf.html (if not explicitly stated otherwise)

Computer Science's Digest Volume 2

This series of textbooks was created for the students of the Systems Engineering Program at the University of Nariño. They have been intentionally written in English to promote reading in a foreign language. The textbooks are a collection of reflections and workshops on specific situations in the field of computer science, based on the authors’ experiences. The main purpose of these textbooks is essentially academic. The way in which the reflections and workshops were constructed follows a didactic structure, to facilitate teaching and learning, making use of English as a second language. This book covers Internet and Multimedia Technology, System Analysis and Design, and Software Engineerin