No abstract

Abstract. This paper presents a model for representing compliance rules related to subsurface objects. Rules expressed in this model can be automatically evaluated (using SHACL or SPARQL) on existing 3D city models expressed in RDF. The main characteristics of the proposed model are (1) its expressiveness, that comes from the use of formal ontologies for representing the rules and the objects they refer to, (2) its integrative nature, given by the interconnection among the proposed ontologies and the connection of these ontologies with CityGML and IFC (in an ontological form), and (3) its multi-geometry aspect. Preliminary results allow to automatically evaluate formally expressed compliance rules for underground objects in a 3D city model, that will considerably ease the task of professionals of the field.

Abstract. Urban planning projects are complex and involve multiple actors ranging from urban planners to inhabitants. These actors differ greatly in their background or their centres of interest. The main objective of our research is contributing to a better communication of urban planning projects between the various actors involved. With this intention, we defined an ontology-based model whose main characteristics are, on the one hand, the semantic integration in a knowledge base of the urban knowledge coming from various sources such as GIS databases, master plans, local plans or any other document and, on the other hand, the modelling of the centre of interest of an urban actor. This models can then be used to generate adapted user interfaces to present the project's data and knowledge according to each actor's background and interests.

KEY WORDS: 3D visualization, information visualization, 3D city model, 3D virtual environment, 3D GIS, knowledge base ABSTRACT:Virtual 3D city models are used for different applications such as urban planning, navigation, pedestrian behaviour, historical information, and disaster management. These applications require rich information models that associate urban objects not only with their geometric properties but also with other types of information. When designing such models the choice of visualization techniques is far from trivial because the city objects must be displayed together with additional information, such as historical facts, planning projects, pollutant concentration, noise level, etc. Finding relevant techniques depends on a set of criteria such as the type of information, but also on the tasks that will be performed and the associated context. Furthermore, a technique that is relevant when used in isolation may generate visual incompatibilities when used in conjunction with another one. We have defined a model for the representation of information visualization techniques in 3D city models. We have implemented this model in the form of an ontology and a knowledge base of techniques currently used in 3D city models or 3D GIS. The goal of such an approach is to provide a knowledge repository to support the design of 3D virtual city models in which non-geometric information must be presented. In this paper we describe the model and the ontology of information visualization techniques that we designed. We also show how the associated knowledge base can be used for the selection of visualization techniques depending on different criteria including task and context, and for the detection of visual incompatibilities between techniques when used in the same scene.

Abstract. Models, which represent in 3 dimensions the geometric elements of a city, are called 3D city models. Those models are used for an intended wide range of applications beyond mere visualization. Such uses are made possible by enriching the geometrical aspects with urban or environmental data that cannot be perceptible to a user without a visual abstraction. Using such models implies interacting with them in order to perform specific tasks related to the visualized data. Those data are potentially heterogeneous in terms of types, scales, issues, etc. When creating an enriched 3D city model, the designer faces the problem of choosing the most relevant visualization techniques for those heterogeneous data that have to be displayed within the same scene. In this paper we address the problem related to the visualization of enriched 3D city models by proposing a formal representation of existing visualization techniques in the form of an ontology of 3D visualization techniques. We also show how this ontology can be used for computational reasoning and help for the selection of visualization techniques by checking if a technique is compatible with a dataset to display or to a technique already selected and used in the same scene.

Enterprises today face many challenges related to lack of interoperability. Enterprise applications and software systems need to be interoperable in order to achieve seamless business across organisational boundaries and thus achieve virtual networked organisations. IEEE defines interoperability as “the ability of two or more systems or components to exchange information and to use the information that has been exchanged”. MDA is the OMG instantiation of an approach to software development kown as Model Driven Engineering (MDE) or Model Driven Development (MDD). MDD focuses on Models as the primary artefacts in the development process, with Transformations as the primary operation on models, used to map information from one model to another. There is presently an important paradigm shift in the field of software engineering that may have important consequences on the way information systems are built and maintained. Model-driven development (MDD), and in particular OMG's Model-Driven Architecture ® (MDA®), is emerging as the state of practice for developing modern enterprise applications and software systems. The MDD paradigm improves the way of addressing and solving interoperability issues compared to earlier non-modelling approaches. However, developing correct and useful models is not an easy task. We believe that there is a need for an interoperability framework that provides guidance on how MDD should be applied to address interoperability. A key to the success of MDD is the development of ontologies supporting the mapping from one model to another, either at the same level of abstraction or at different levels. Various approaches have been proposed and tested, starting from common ontologies, shared by all the models, to local ontologies, specific to each software. We propose here to discuss the applicability of MDD to the urban civil engineering (UCE) field. This should help to establish the requirements for ontologies to be applied for interoperability of systems commonly used in this domain. In the first section of this paper, we briefly introduce some key principles of the MDA approach and the role of ontologies in model transformation approaches. The following section describes the Model Driven Development (MDD) interoperability framework. The last part presents a way of applying the MDA techniques to urban civil engineering projects, with the objective of testing the feasibility and relevancy of the approach to this domain

This technical paper is a contribution to the identification of current challenges of semantic 3D city models. They are presented in four parts, namely 3D enriched city models and their connection with urban information models and smartcities, urban models integration, urban analyses and data. This work is an output of the COST Action TU0801 “Semantic Enrichment of 3D city models for sustainable urban development”.

No abstract