Modeling of RL- cities (original) (raw)
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2001
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City modelling is a topic which has been on the agenda for a long time and two main approaches from different angles in this field can be identified. GIS experts have attempted over the years (in collaboration with programmers) to build information systems for cities by means of combining graphical information with related metadata. Architects also started to get involved in this field. However, they were mainly interested in the spatial aspects of a city model and created their own “city models” for different purposes. Today crucial questions concerning the creation itself are resolved, the vision of implementation into daily work becomes more and more important. In other words: “what to do” with the accumulated data. This paper intends to identify the core role of the architect in the field of 3D-city modelling.
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2009
The new 3D standard CityGML has been attracting a lot of attention in the last few years. Many characteristics of the XML-based format make it suitable for storage and exchange of virtual 3D city models. It provides possibilities to store semantic and geometric information and has the potential to incorporate topological models. A large number of CityGML models are already available in different parts of the world. However, still the creation of a 3D model according to conceptual schema of CityGML remains a challenge. In this paper we present a modeling software Toposcopy, which allows for creating 3D models and exporting them in CityGML format. Toposcopy follows basically a close-range photogrammetric approach to re-constructs 3D models with the help of 2D map and terrestrial geo-referenced images. The approach uses perspective projection to link points on the photos with the corresponding points on the 2D map. A soon as the 3D model is re-constructed, it can be organised according to CityGML spatial schema. Toposcopy appeared to be a handy tool to produce CityGML in LOD 1, 2 and 3. The process of modeling is relatively fast, since various parametric shapes can be applied for a large number of houses. Import and export routines are written, that allows visualizing spatial designs in a 3D topographic data-set. The developed software was tested in several projects. The paper will present the software, the performed tests and will discuss challenges in creating of CityGML features. The paper concludes with suggestions for improving CityGML
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Copyright © 2003, Idea Group Inc. Copying or distributing in print or electronic forms without written permission of Idea Group Inc. is prohibited. ABSTRACT Our project deals with the reuse of existent urban models into an interconnection schema. An urban model is a specialised tool for simulating or estimating phenomena about the city. Using a specific technique of encapsulation, with a semi-automatic generation of communication drivers, the proposed environment offers a homogeneous view of the urban models, which may be used into a distributed environment. In this paper, we present the global distributed architecture, created with Java, and the chosen representation of the interconnection schema, explaining how this particular approach is well dedicated to manage the distributed urban models. This paper shows the advantage offered by the XML syntax to represent meta-data and specific data, and by a strong hierarchical management.
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Chapter 2 Representing and Exchanging 3 D City Models with CityGML
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CityGML is an open data model and XML-based format for the representation and exchange of virtual 3D city models. It is based on the Geography Markup Language version 3.1.1 (GML3). Both CityGML and GML3 are international standards issued by the Open Geospatial Consortium (OGC). CityGML not only represents the shape and graphical appearance of city models but specifically addresses the object semantics and the representation of the thematic properties, taxonomies and aggregations. The paper gives an overview about CityGML, its modelling aspects and design decisions, recent applications, and its relation to other 3D standards like IFC, X3D, and KML. 2.1 Semantic 3D City Models Virtual 3D city models have been used in the past mainly for the visualisation or graphical exploration of cityscapes. Nowadays, an increasing number of applications like environmental and training simulations, urban planning and facility management, disaster management and homeland security, and personal naviga...
City Induction: a model for formulating, generating, and evaluating urban designs
Transportation, 2010
Abstract. Urban planning and design have a considerable impact on the economic performance of cities and on the quality of life of the population. Efficiency at this level is hampered by the lack of integrated instruments for formulating, generating, and evaluating urban plans. This chapter describes the theoretical foundations of a research project, called City Induction, aimed at the creation of a model for the development of such an instrument, departing from existing theories, which are integrated through a discursive grammar. The proposed model is composed of three sub-models: (1) a model for formulating urban programs from the analysis and interpretation of the context, based on Alexander’s pattern language; (2) a model for generating urban plans that match the program, based on Stiny’s shape and description grammars; and (3) a model for evaluating urban plans, that can be used for analyzing, comparing and ranking alternative solutions, departing from Hillier’s space syntax. A common urban space ontology guarantees the syntactic and semantic interoperability among the three sub-models. This ontology will be used to structure and codify information into a Geographic Information System (GIS), which will be the kernel for the computer implementation of the larger model. A CAD system is used to construct 3D models from contextual information stored in the GIS. In short, following Stiny and March’s design machines concept, the goal is to create an urban design machine that is able to produce flexible urban plans at the site planning level. Keywords: urban design, ontology, pattern language, shape grammars, space syntax, GIS, CAD
2020
Urban spatial models are important to many professions, and they can be used in a wide range of urban decision-making applications. This paper describes a methodology for automatic generation of an urban spatial model from a GIS source. The methodology uses a Voronoi polygon-based method in order to split the urban space. After partitioning the GIS, functional characteristics are used to generate zones of interest at each Voronoi polygon. The paper also presents examples of applications of the model: a two dimensional model used for microsimulation of traffic, and a three-dimensional model used for simulation of air pollution. KEYWORDS: mobility, urban model, Voronoi diagram, GIS, distributed system The spatial data representation of urban systems presents several challenges. Data may be heterogeneous, unordered, or they may come from multiple sources. The classical geographical information systems (GIS) approach use layers as data representation units; each layer is related to a su...