Towards Defining a Framework for the Automatic Derivation of 3D CityGML Models from Volunteered Geographic Information

2012 ◽  
Vol 1 (2) ◽  
pp. 1-16 ◽  
Author(s):  
Marcus Goetz ◽  
Alexander Zipf
Keyword(s):  
Volunteered Geographic Information ◽  
Geographic Information ◽  
3D City Models ◽  
The Past ◽  
Urban City ◽  
Building Models ◽  
Data Source ◽  
The Creation ◽  
City Models ◽  
Urban Data

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.

scholarly journals ENHANCEMENT OF GENERIC BUILDING MODELS BY RECOGNITION AND ENFORCEMENT OF GEOMETRIC CONSTRAINTS

2016 ◽  
Vol III-3 ◽  
pp. 333-338 ◽  
Author(s):  
J. Meidow ◽  
H. Hammer ◽  
M. Pohl ◽  
D. Bulatov
Keyword(s):  
Laser Scanning ◽  
Initial Point ◽  
Real Data ◽  
Boundary Representation ◽  
Geometric Constraints ◽  
Data Set ◽  
3D City Models ◽  
Building Models ◽  
Recognition And Enforcement ◽  
City Models

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.

scholarly journals TOWARDS WIND-SIMULATION OF VIRTUAL 3D CITY MODELS IN A COLLABORATIVE VR ENVIRONMENT

2019 ◽  
Vol XLII-4/W15 ◽  
pp. 61-66 ◽  
Author(s):  
R. Piepereit ◽  
A. Beuster ◽  
M. von der Gruen ◽  
U. Voß ◽  
M. Pries ◽  
...  
Keyword(s):  
Flow Simulation ◽  
Level Of Detail ◽  
Planning Systems ◽  
3D City Models ◽  
Building Models ◽  
Wind Simulation ◽  
Development Processes ◽  
City Model ◽  
Simulation Results ◽  
City Models

<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>

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
Keyword(s):  
Sustainable Development ◽  
Urban Planning ◽  
3D Modeling ◽  
Automatic Generation ◽  
Integrated System ◽  
Digital Maps ◽  
3D City Models ◽  
Building Models ◽  
Modeling Software ◽  
City Models

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.

scholarly journals Participatory mapping of regional food assets using volunteered geographic information systems

2021 ◽  
Author(s):  
Victoria Fast
Keyword(s):  
Food Systems ◽  
Food System ◽  
Local Food ◽  
Volunteered Geographic Information ◽  
Geographic Information ◽  
Participatory Mapping ◽  
Regional Food ◽  
The Creation ◽  
Systems Framework ◽  
The Impact

Local food systems are increasingly being studied in response to the threats imposed on global agri-industrial food systems. Central to local food is the community who is imaging and implementing diverse and hyper-local food assets, which are making a significant, but largely unknown, contribution to food security, resiliency, and sustainability. It is important to align these assets with broader regional food policies, programs, and regulations. However, there are few mechanisms to engage stakeholders or share local information. One possible mechanism to learn about local food assets is volunteered geographic information (VGI); a phenomenon that blends crowdsourcing, citizen science, and online mapping. It is currently being studied for its ability to engage and gather information from diverse and under-represented groups. This policy-relevant research investigates how VGI can support greater engagement and knowledge sharing across diverse food stakeholders. To achieve this objective, the VGI system framework is established to study the processes that support the creation of VGI. Next, the new era of food mapping, dubbed Food Mapping 2.0, is investigated to understand the impact evolving mapping techniques have on the engagement of food stakeholders. Lastly, the VGI systems framework, which is embedded in participatory geographic information system and participatory action research methods, is applied to support participatory mapping of regional food assets in Durham Region. His research gathered contributions on over 200 food assets in Durham Region – an upper-tier municipality just east of Toronto consisting of eight lower-tier municipalities – effectively capturing the distributed intelligence of government, not-for-profit, and community stakeholders. The crowdsourced data include locations, descriptions, and media related to farms, markets, community gardens, foodscapes, and other innovative food assets. The community identified urban food assets as a central strength of the regional food system. Overall, this project enabled the creation of an open food assets dataset, further supporting the development of an online Food Assets map and a Crowdsourcing Urban Food Assets report, which are collective used to inform future food policy, regulation, and program development. Overall, this research revealed a uniquely local and community-driven perspective about food system assets within Durham, while serving as a prototype of the VGI systems framework.

scholarly journals TESTING THE IMPACT OF 2D GENERALISATION ON 3D MODELS – EXPLORING ANALYSIS OPTIONS WITH AN OFF-THE-SHELF SOFTWARE PACKAGE

2018 ◽  
Vol XLII-4/W10 ◽  
pp. 119-126
Author(s):  
E. Muñumer Herrero ◽  
C. Ellul ◽  
J. Morley
Keyword(s):  
3D Models ◽  
3D Analysis ◽  
Spatial Analyses ◽  
3D City Models ◽  
The Third ◽  
The Past ◽  
Processing Times ◽  
Third Dimension ◽  
The Impact ◽  
City Models

<p><strong>Abstract.</strong> Popularity and diverse use of 3D city models has increased exponentially in the past few years, providing a more realistic impression and understanding of cities. Often, 3D city models are created by elevating the buildings from a detailed 2D topographic base map and subsequently used in studies such as solar panel allocation, infrastructure remodelling, antenna installations or even tourist guide applications. However, the large amount of resulting data slows down rendering and visualisation of the 3D models, and can also impact the performance of any analysis. Generalisation enables a reduction in the amount of data – however the addition of the third dimension makes this process more complex, and the loss of detail resulting from the process will inevitably have an impact on the result of any subsequent analysis.</p><p>While a few 3D generalization algorithms do exist in a research context, these are not available commercially. However, GIS users can create the generalised 3D models by simplifying and aggregating the 2D dataset first and then extruding it to the third dimension. This approach offers a rapid generalization process to create a dataset to underpin the impact of using generalised data for analysis. Specifically, in this study, the line of sight from a tall building and the sun shadow that it creates are calculated and compared, in both original and generalised datasets. The results obtained after the generalisation process are significant: both the number of polygons and the number of nodes are minimized by around 83<span class="thinspace"></span>% and the volume of 3D buildings is reduced by 14.87<span class="thinspace"></span>%. As expected, the spatial analyses processing times are also reduced. The study demonstrates the impact of generalisation on analytical results – which is particularly relevant in situations where detailed data is not available and will help to guide the development of future 3D generalisation algorithms. It also highlights some issues with the overall maturity of 3D analysis tools, which could be one factor limiting uptake of 3D GIS.</p>

scholarly journals Participatory mapping of regional food assets using volunteered geographic information systems

2021 ◽  
Author(s):  
Victoria Fast
Keyword(s):  
Food Systems ◽  
Food System ◽  
Local Food ◽  
Volunteered Geographic Information ◽  
Geographic Information ◽  
Participatory Mapping ◽  
Regional Food ◽  
The Creation ◽  
Systems Framework ◽  
The Impact

Local food systems are increasingly being studied in response to the threats imposed on global agri-industrial food systems. Central to local food is the community who is imaging and implementing diverse and hyper-local food assets, which are making a significant, but largely unknown, contribution to food security, resiliency, and sustainability. It is important to align these assets with broader regional food policies, programs, and regulations. However, there are few mechanisms to engage stakeholders or share local information. One possible mechanism to learn about local food assets is volunteered geographic information (VGI); a phenomenon that blends crowdsourcing, citizen science, and online mapping. It is currently being studied for its ability to engage and gather information from diverse and under-represented groups. This policy-relevant research investigates how VGI can support greater engagement and knowledge sharing across diverse food stakeholders. To achieve this objective, the VGI system framework is established to study the processes that support the creation of VGI. Next, the new era of food mapping, dubbed Food Mapping 2.0, is investigated to understand the impact evolving mapping techniques have on the engagement of food stakeholders. Lastly, the VGI systems framework, which is embedded in participatory geographic information system and participatory action research methods, is applied to support participatory mapping of regional food assets in Durham Region. His research gathered contributions on over 200 food assets in Durham Region – an upper-tier municipality just east of Toronto consisting of eight lower-tier municipalities – effectively capturing the distributed intelligence of government, not-for-profit, and community stakeholders. The crowdsourced data include locations, descriptions, and media related to farms, markets, community gardens, foodscapes, and other innovative food assets. The community identified urban food assets as a central strength of the regional food system. Overall, this project enabled the creation of an open food assets dataset, further supporting the development of an online Food Assets map and a Crowdsourcing Urban Food Assets report, which are collective used to inform future food policy, regulation, and program development. Overall, this research revealed a uniquely local and community-driven perspective about food system assets within Durham, while serving as a prototype of the VGI systems framework.

scholarly journals VOLUMINATOR 2.0 – SPEEDING UP THE APPROXIMATION OF THE VOLUME OF DEFECTIVE 3D BUILDING MODELS

2016 ◽  
Vol III-2 ◽  
pp. 29-36 ◽  
Author(s):  
M. Sindram ◽  
T. Machl ◽  
H. Steuer ◽  
M. Pültz ◽  
T. H. Kolbe
Keyword(s):  
Energy Demand ◽  
Computation Time ◽  
Building Energy ◽  
Common Information ◽  
Topological Relationships ◽  
Building Models ◽  
Thematic Information ◽  
Data Source ◽  
Topological Errors ◽  
City Models

Semantic 3D city models are increasingly used as a data source in planning and analyzing processes of cities. They represent a virtual copy of the reality and are a common information base and source of information for examining urban questions. A significant advantage of virtual city models is that important indicators such as the volume of buildings, topological relationships between objects and other geometric as well as thematic information can be derived. Knowledge about the exact building volume is an essential base for estimating the building energy demand. In order to determine the volume of buildings with conventional algorithms and tools, the buildings may not contain any topological and geometrical errors. The reality, however, shows that city models very often contain errors such as missing surfaces, duplicated faces and misclosures. To overcome these errors (Steuer et al., 2015) have presented a robust method for approximating the volume of building models. For this purpose, a bounding box of the building is divided into a regular grid of voxels and it is determined which voxels are inside the building. The regular arrangement of the voxels leads to a high number of topological tests and prevents the application of this method using very high resolutions. In this paper we present an extension of the algorithm using an octree approach limiting the subdivision of space to regions around surfaces of the building models and to regions where, in the case of defective models, the topological tests are inconclusive. We show that the computation time can be significantly reduced, while preserving the robustness against geometrical and topological errors.

scholarly journals Modelling Buildings in CityGML LOD1: Building Parts, Terrain Intersection Curve and Address Features

2021 ◽  
Author(s):  
Evgeny Shirinyan ◽  
Dessislava Petrova-Antonova
Keyword(s):  
Multiple Sources ◽  
Intersection Curve ◽  
3D City Models ◽  
Building Model ◽  
3D City Model ◽  
Building Models ◽  
City Model ◽  
Open Datasets ◽  
Multiple Domains ◽  
City Models

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.

scholarly journals Revealing Cultural Ecosystem Services through Instagram Images: The Potential of Social Media Volunteered Geographic Information for Urban Green Infrastructure Planning and Governance

2016 ◽  
Vol 1 (2) ◽  
pp. 1-17 ◽  
Author(s):  
Paulina Guerrero ◽  
Maja Steen Møller ◽  
Anton Stahl Olafsson ◽  
Bernhard Snizek
Keyword(s):  
Social Media ◽  
Spatial Data ◽  
Green Infrastructure ◽  
Volunteered Geographic Information ◽  
Distribution Patterns ◽  
Collaborative Governance ◽  
Geographic Information ◽  
Urban Green ◽  
Data Source ◽  
Rich Data

With the prevalence of smartphones, new ways of engaging citizens and stakeholders in urban planning and governance are emerging. The technologies in smartphones allow citizens to act as sensors of their environment, producing and sharing rich spatial data useful for new types of collaborative governance set-ups. Data derived from Volunteered Geographic Information (VGI) can support accessible, transparent, democratic, inclusive, and locally-based governance situations of interest to planners, citizens, politicians, and scientists. However, there are still uncertainties about how to actually conduct this in practice. This study explores how social media VGI can be used to document spatial tendencies regarding citizens’ uses and perceptions of urban nature with relevance for urban green space governance. Via the hashtag <em>#sharingcph</em>, created by the City of Copenhagen in 2014, VGI data consisting of geo-referenced images were collected from Instagram, categorised according to their content and analysed according to their spatial distribution patterns. The results show specific spatial distributions of the images and main hotspots. Many possibilities and much potential of using VGI for generating, sharing, visualising and communicating knowledge about citizens’ spatial uses and preferences exist, but as a tool to support scientific and democratic interaction, VGI data is challenged by practical, technical and ethical concerns. More research is needed in order to better understand the usefulness and application of this rich data source to governance.

scholarly journals Method for 3D City Building Continuous Transformation Based on an Improved LOD Topological Data Structure

2019 ◽  
Vol 8 (11) ◽  
pp. 504
Author(s):  
Siyi Li ◽  
Wenjing Li ◽  
Zhiyong Lin ◽  
Shengjie Yi
Keyword(s):  
Data Structure ◽  
Level Of Detail ◽  
Continuous Transformation ◽  
3D City Models ◽  
3D City Model ◽  
Building Models ◽  
City Model ◽  
Lod Models ◽  
Topological Data Structure ◽  
City Models

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.

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