Automatic Generation of 3D Building Models with General Shaped Roofs for Sustainable Development

2013 ◽  
Vol 368-370 ◽  
pp. 1855-1859 ◽  
Author(s):  
Kenichi Sugihara ◽  
Zhen Jiang Shen

3D city models are important in urban planning for sustainable development. Usually and traditionally, urban planners design the future layout of the towns by drawing the maps, using GIS or CAD packages. 3D city models based on these maps are quite effective in understanding what if the plan is realized. However, creating 3D city models is labor intensive, using a 3D modeling software such as 3ds Max or SketchUp. In order to automate laborious steps, we are proposing a GIS and CG integrated system for automatically generating 3D building models with general shaped roofs by straight skeleton computation, based on general shaped building polygons (building footprints) on digital maps.

Author(s):  
J. Meidow ◽  
H. Hammer ◽  
M. Pohl ◽  
D. Bulatov

Many buildings in 3D city models can be represented by generic models, e.g. boundary representations or polyhedrons, without expressing building-specific knowledge explicitly. Without additional constraints, the bounding faces of these building reconstructions do not feature expected structures such as orthogonality or parallelism. The recognition and enforcement of man-made structures within model instances is one way to enhance 3D city models. Since the reconstructions are derived from uncertain and imprecise data, crisp relations such as orthogonality or parallelism are rarely satisfied exactly. Furthermore, the uncertainty of geometric entities is usually not specified in 3D city models. Therefore, we propose a point sampling which simulates the initial point cloud acquisition by airborne laser scanning and provides estimates for the uncertainties. We present a complete workflow for recognition and enforcement of man-made structures in a given boundary representation. The recognition is performed by hypothesis testing and the enforcement of the detected constraints by a global adjustment of all bounding faces. Since the adjustment changes not only the geometry but also the topology of faces, we obtain improved building models which feature regular structures and a potentially reduced complexity. The feasibility and the usability of the approach are demonstrated with a real data set.


Author(s):  
G. Floros ◽  
D. Solou ◽  
I. Pispidikis ◽  
E. Dimopoulou

The methodologies of 3D modeling techniques have increasingly increased due to the rapid advances of new technologies. Nowadays, the focus of 3D modeling software is focused, not only to the finest visualization of the models, but also in their semantic features during the modeling procedure. As a result, the models thus generated are both realistic and semantically enriched. Additionally, various extensions of modeling software allow for the immediate conversion of the model’s format, via semi-automatic procedures with respect to the user’s scope. The aim of this paper is to investigate the generation of a semantically enriched Citygml building model via two different methodologies. The first methodology includes the modeling in Trimble SketchUp and the transformation in FME Desktop Manager, while the second methodology includes the model’s generation in CityEngine and its transformation in the CityGML format via the 3DCitiesProject extension for ArcGIS. Finally, the two aforesaid methodologies are being compared and specific characteristics are evaluated, in order to infer the methodology that is best applied depending on the different projects’ purposes.


Author(s):  
R. Piepereit ◽  
A. Beuster ◽  
M. von der Gruen ◽  
U. Voß ◽  
M. Pries ◽  
...  

<p><strong>Abstract.</strong> Virtual reality (VR) technologies are used more and more in product development processes and are upcoming in urban planning systems as well. They help to visualize big amounts of data in self-explanatory way and improve people’s interpretation of results. In this paper we demonstrate the process of visualizing a city model together with wind simulation results in a collaborative VR system. In order to make this kind of visualization possible a considerable amount of preliminary work is necessary: healing and simplification of building models, conversion of these data into an appropriate CAD-format and numerical simulation of wind flow around the buildings. The data obtained from these procedures are visualized in a collaborative VR-System. In our approach CityGML models in the LoD (Level of Detail) 1, 2 and 3 can be used as an input. They are converted into the STEP format, commonly used in CAD for simulation and representation. For this publication we use an exemplary LoD1 model from the district Stöckach-Stuttgart. After preprocessing the model, the results are combined with those of an air flow simulation and afterwards depicted in a VR system with a HTC Vive as well as in a CAVE and a Powerwall. This provides researchers, city planners and technicians with the means to flexibly and interactively exchange simulation results in a virtual environment.</p>


Author(s):  
Evgeny Shirinyan ◽  
Dessislava Petrova-Antonova

3D city models integrate heterogeneous urban data from multiple sources in a unified geospatial representation, combining both semantics and geometry. Although in the last decades, they are predominantly used for visualization, today they are used in a large range of tasks related to exploration, analysis, and management across multiple domains. The complexity of urban processes and the diversity of urban environment bring challenges to the implementation of 3D city models. To address such challenges, this paper presents the development process of a 3D city model of a single neighborhood in Sofia city based on CityGML 2.0 standard. The model represents the buildings in LOD1 with a focus on CityGML features of related to the buildings like building part, terrain intersection curve and address. Similar building models of 18 cities provided as open datasets are explored and compared in order to extract good modeling practices. As a result, workflows for generation of 3D building models in LOD1 are elaborated and improvements in the feature modeling are proposed. Two options of building model are examined: modeling of a building as a single solid and modeling of a building with separate building parts. Finally, the possibilities for visualization of the model in popular platforms such as ArcGIS Pro and Cesium Ion are explored.


2019 ◽  
Vol 8 (11) ◽  
pp. 504
Author(s):  
Siyi Li ◽  
Wenjing Li ◽  
Zhiyong Lin ◽  
Shengjie Yi

A 3D city model is an intuitive tool that is used to describe cities. Currently, level-of-detail (LOD) technology is used to meet different visual demands for 3D city models by weighting the rendering efficiency against the details of the model. However, when the visual demands change, the “popping” phenomenon appears when making transformations between different LOD models. We optimized this popping phenomenon by improving the data structure that focuses on 3D city building models and combined it with the facet shift algorithm based on minimal features. Unlike generating finite LOD models in advance, the proposed continuous LOD topology data structure is able to store the changes between different LOD models. By reasonably using the change information, continuous LOD transformation becomes possible. The experimental results showed that the continuous LOD transformation based on the proposed data structure worked well, and the improved data structure also performed well in memory occupation.


2012 ◽  
Vol 1 (2) ◽  
pp. 1-16 ◽  
Author(s):  
Marcus Goetz ◽  
Alexander Zipf

High-quality geographic data sources are eminent for urban data management and the creation of detailed 3D city models. In the past two decades, Volunteered Geographic Information (VGI) increasingly gained attractiveness to both amateur users and professionals, resulting in a broad availability of urban data within VGI communities and especially OpenStreetMap (OSM). OSM provides detailed information about urban regions and more buildings are also mapped. Existing 3D-VGI applications, e.g., KOSMOS Worldflier (Brejc, 2011) or the OSM-3D project (OSM-3D, 2011) only focus on visualization purposes, but a standardized usage for exchanging and sharing urban city models is not combined with VGI. Therefore, this paper presents a framework for an automatic VGI-based creation of 3D building models encoded as standardized CityGML models. The usage of VGI as a proper data source for the creation of standardized city models will be proven.


Geographies ◽  
2021 ◽  
Vol 1 (3) ◽  
pp. 333-345
Author(s):  
Steffen Goebbels ◽  
Regina Pohle-Fröhlich

3D city models are mainly viewed on computer screens, but many municipalities also use 3D printing to make urban planning tangible. Since 3D color printing is still comparatively expensive and the colors often fade over time, many of these models are monochrome. Here, color textured paper models offer an inexpensive and under-appreciated alternative. In this paper, a greedy algorithm adapted to CityGML building models is presented, which creates print templates for such paper models. These 2D layouts consist of cut edges and fold edges that bound polygons of a building. The polygons can be textured or left blank depending on the existence of CityGML textures. Glue tabs are attached to cut edges. In addition to the haptic 3D visualization, the quality of the 3D models can sometimes be better assessed on the basis of the print templates than from a perspective projection. The unfolding procedure was applied to parts of the freely available CityGML model of Berlin as well as to parts of models of the cities of Dortmund and Krefeld.


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