UDMV: EG Workshop on Urban Data Modelling and Visualisation
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Browsing UDMV: EG Workshop on Urban Data Modelling and Visualisation by Subject "Computational Geometry and Object Modeling"
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Item Challenges and Ideas in Procedural Modeling of Interiors(The Eurographics Association, 2013) Ilcik, Martin; Wimmer, Michael; Vincent Tourre and Gonzalo BesuievskyWhile the creation of convincing cityscapes from the outside is already possible, there is a lack of robust and efficient techniques for modeling the interior of buildings. In particular, we focus on challenges for the subdivision of the interior space into rooms and for placement of furniture in those rooms.Item A Data Model for Simulation Models Relying on Spatio-temporal Urban Data(The Eurographics Association, 2016) Langlois, Jean-Gil; Tourre, Vincent; Servières, Myriam; Gervais, B.; Gesquière, Gilles; Vincent Tourre and Filip BiljeckiTo understand the complexity of modern cities and anticipate their expansion, experts from various fields conceive simulation models that can be very different. Those simulation models work with a variety of data with their own organization. Furthermore, because the urban objects are studied in the context of the evolution of a city or urban area, they carry temporal and spatial information (ADD EXAMPLES). In this paper, we present the base classes of a common data model robust and flexible enough to serve the identified use cases (EXAMPLES). We then introduce a mechanism that allows to add thematic information to those classes (AND OTHER MECHANISMS). We also present some possibilities of the use of the data model. (We end this paper by evoking the future improvements of the data model NOT MANDATORY).Item Dynamizers - Modeling and Implementing Dynamic Properties for Semantic 3D City Models(The Eurographics Association, 2015) Chaturvedi, Kanishk; Kolbe, Thomas H.; Filip Biljecki and Vincent TourreToday, more and more cities worldwide are realizing the importance of semantic 3D city models. Various application areas of 3D city models such as simulations require the usage of highly dynamic and time-varying attributes, which are currently not supported by any standard. In this paper, we propose a new concept 'dynamizer', which extends static 3D city models by supporting variations of individual feature properties and associations over time. It allows to inject dynamic variations of city object properties into the static representation. In addition, the concept allows to model and study complex patterns representing dynamic variation of properties based on statistics and general rules.Item Indoor Scene Reconstruction using Primitive-driven Space Partitioning and Graph-cut(The Eurographics Association, 2013) Oesau, Sven; Lafarge, Florent; Alliez, Pierre; Vincent Tourre and Gonzalo BesuievskyWe present a method for automatic reconstruction of permanent structures of indoor scenes, such as walls, floors and ceilings, from raw point clouds acquired by laser scanners. Our approach employs graph-cut to solve an inside/outside labeling of a space decomposition. To allow for an accurate reconstruction the space decomposition is aligned with permanent structures. A Hough Transform is applied for extracting the wall directions while allowing a flexible reconstruction of scenes. The graph-cut formulation takes into account data consistency through an inside/outside prediction for the cells of the space decomposition by stochastic ray casting, while favoring low geometric complexity of the model. Our experiments produces watertight reconstructed models of multi-level buildings and complex scenes.Item Managing Temporal Change of Cities with CityGML(The Eurographics Association, 2014) Morel, Maxime; Gesquière, Gilles; Gonzalo Besuievsky and Vincent TourreAn increasing number of cities are developing digital models. It becomes thus necessary to take into account changes over time. Interoperability and thus the use of standards is also recommended. In this paper, we propose a new method, based on CityGML to take into account changes in the objects which compose the city. This method is efficient for any kind of changes of the city objects (semantic, geometry, topology or appearance). We then propose an extension of our method in order to consider more frequent changes as it is the case with sensors data that can be linked with part of city objects.Item Online Reconstruction of Textured Triangle Meshes from Aerial Images(The Eurographics Association, 2013) Vierjahn, Tom; Roters, Jan; Moser, Manuel; Hinrichs, Klaus; Mostafawy, Sina; Vincent Tourre and Gonzalo BesuievskyIn this paper we present and evaluate a new online reconstruction algorithm to create a textured triangle mesh from a set of aerial images via an unorganized point cloud. Both the point cloud and the mesh are iteratively refined while allowing new aerial images to be added at any time during reconstruction. Texture coordinates are learnt to instantly visualize an initially rough approximation that gets refined as more data becomes available. The new algorithm improves upon other systems that require the complete data to be acquired beforehand, and that apply offline, non-iterative reconstruction and processing. Thus, our algorithm is perfectly suited for time-critical applications, e. g., strategical visualization platforms for disaster and emergency response.Item Topological Reconstruction of Complex 3D Buildings and Automatic Extraction of Levels of Detail(The Eurographics Association, 2014) Diakité, Abdoulaye A.; Damiand, Guillaume; Maercke, Dirk Van; Gonzalo Besuievsky and Vincent TourreThis paper describes a new method allowing to retrieve the indoor and outdoor topology of a detailed 3D building model from its geometry and to extract different levels of detail (LoD) from the resulting topological description. No prior information about the initial model, except its geometric information is needed as input, and using the combinatorial maps data structure, the method recovers the topological information of the identified parts of the building. The topology is needed for most of the applications using 3D building models after the architects design it. While classical models available are mainly furnished in a Boundary Representation (B-Rep) format, we discuss how to recover the components that allow to distinguish the several parts of the building (defined as volumes) then the spatial relationships linking them.Item Visibility Analysis in a Point Cloud Based on the Medial Axis Transform(The Eurographics Association, 2015) Peters, Ravi; Ledoux, Hugo; Biljecki, Filip; Filip Biljecki and Vincent TourreVisibility analysis is an important application of 3D GIS data. Current approaches require 3D city models that are often derived from detailed aerial point clouds. We present an approach to visibility analysis that does not require a city model but works directly on the point cloud. Our approach is based on the medial axis transform, which models the urban environment as a union of balls, which we then use to construct a depthmap that is used for point visibility queries. As we demonstrate through our experiments on a real-world aerial LiDAR point cloud, the main benefits of our approach are 1) it is robust to noise, irregular sampling and holes of typical aerial LiDAR datasets, 2) it gives visibility results that are significantly more accurate than the often highly generalised city models, and 3) it is a simple algorithm that is easy to parallelise.