scholarly journals TRIANGULAR MESH APPROACH FOR AUTOMATIC REPAIR OF MISSING SURFACES OF LOD2 BUILDING MODELS

2022 ◽  
Vol XLVI-4/W3-2021 ◽  
pp. 281-286
Author(s):  
H. Rashidan ◽  
A. Abdul Rahman ◽  
I. A. Musliman ◽  
G. Buyuksalih
Keyword(s):  
Urban Areas ◽  
Visual Analysis ◽  
3D Models ◽  
Triangular Mesh ◽  
Hole Filling ◽  
3D City Models ◽  
Building Model ◽  
3D Building Model ◽  
Topological Errors ◽  
City Models

Abstract. 3D city models are increasingly being used to represent the complexity of today’s urban areas, as they aid in understanding how different aspects of a city can function. For instance, several municipalities and governmental organisations have constructed their 3D city models for various purposes. These 3D models, which are normally complex and contain semantics information, have typically been used for visualisation and visual analysis purposes. However, most of the available 3D models open datasets contain many geometric and topological errors, e.g., missing surfaces (holes), self-intersecting surfaces, duplicate vertices, etc. These errors prevent the datasets from being used for advanced applications such as 3D spatial analysis which requires valid datasets and topology to calculate its volume, detect surface orientation, area calculation, etc. Therefore, certain repairs must be done before taking these models into actual applications, and hole-filling (of missing surfaces) is an important one among them. Several studies on the topic of automatic repair of the 3D model have been conducted by various researchers, with different approaches have been developed. Thus, this paper describes a triangular mesh approach for automatically repair invalid (missing surfaces) 3D building model (LOD2). The developed approach demonstrates an ability to repair missing surfaces (with holes) in a 3D building model by reconstructing geometries of the holes of the affected model. The repaired model is validated and produced a closed-two manifold model.

scholarly journals INVESTIGATING INTEROPERABILITY CAPABILITIES BETWEEN IFC AND CITYGML LOD 4 – RETAINING SEMANTIC INFORMATION

2018 ◽  
Vol XLII-4/W10 ◽  
pp. 33-40 ◽  
Author(s):  
G. S. Floros ◽  
C. Ellul ◽  
E. Dimopoulou
Keyword(s):  
Semantic Information ◽  
Open Data ◽  
3D Models ◽  
Solar Panels ◽  
3D City Models ◽  
Information Models ◽  
Building Information ◽  
Consistent Manner ◽  
3D Information ◽  
City Models

<p><strong>Abstract.</strong> Applications of 3D City Models range from assessing the potential output of solar panels across a city to determining the best location for 5G mobile phone masts. While in the past these models were not readily available, the rapid increase of available data from sources such as Open Data (e.g. OpenStreetMap), National Mapping and Cadastral Agencies and increasingly Building Information Models facilitates the implementation of increasingly detailed 3D Models. However, these sources also generate integration challenges relating to heterogeneity, storage and efficient management and visualization. CityGML and IFC (Industry Foundation Classes) are two standards that serve different application domains (GIS and BIM) and are commonly used to store and share 3D information. The ability to convert data from IFC to CityGML in a consistent manner could generate 3D City Models able to represent an entire city, but that also include detailed geometric and semantic information regarding its elements. However, CityGML and IFC present major differences in their schemas, rendering interoperability a challenging task, particularly when details of a building’s internal structure are considered (Level of Detail 4 in CityGML). The aim of this paper is to investigate interoperability options between the aforementioned standards, by converting IFC models to CityGML LoD 4 Models. The CityGML Models are then semantically enriched and the proposed methodology is assessed in terms of model’s geometric validity and capability to preserve semantics.</p>

3D City Modeling and Visualization for Smart Phone Applications

2012 ◽  
pp. 254-296
Author(s):  
Juha Hyyppä ◽  
Lingli Zhu ◽  
Zhengjun Liu ◽  
Harri Kaartinen ◽  
Anttoni Jaakkola
Keyword(s):  
Data Acquisition ◽  
Laser Scanning ◽  
3D Models ◽  
Image Capture ◽  
3D City Models ◽  
Central Computer ◽  
3D Data ◽  
Open Operation ◽  
City Modeling ◽  
City Models

Smartphones with larger screens, powerful processors, abundant memory, and an open operation system provide many possibilities for 3D city or photorealistic model applications. 3D city or photorealistic models can be used by the users to locate themselves in the 3D world, or they can be used as methods for visualizing the surrounding environment once a smartphone has already located the phone by other means, e.g. by using GNSS, and then to provide an interface in the form of a 3D model for the location-based services. In principle, 3D models can be also used for positioning purposes. For example, matching of images exported from the smartphone and then registering them in the existing 3D photorealistic world provides the position of the image capture. In that process, the central computer can do a similar image matching task when the users locate themselves interactively into the 3D world. As the benefits of 3D city models are obvious, this chapter demonstrates the technology used to provide photorealistic 3D city models and focus on 3D data acquisition and the methods available in 3D city modeling, and the development of 3D display technology for smartphone applications. Currently, global geoinformatic data providers, such as Google, Nokia (NAVTEQ), and TomTom (Tele Atlas), are expanding their products from 2D to 3D. This chapter is a presentation of a case study of 3D data acquisition, modeling and mapping, and visualization for a smartphone, including an example based on data collected by mobile laser scanning data from the Tapiola (Espoo, Finland) test field.

scholarly journals PLASTIC SURGERY FOR 3D CITY MODELS: A PIPELINE FOR AUTOMATIC GEOMETRY REFINEMENT AND SEMANTIC ENRICHMENT

2021 ◽  
Vol V-4-2021 ◽  
pp. 17-24
Author(s):  
O. Wysocki ◽  
B. Schwab ◽  
L. Hoegner ◽  
T. H. Kolbe ◽  
U. Stilla
Keyword(s):  
Point Clouds ◽  
3D Models ◽  
Data Types ◽  
Automated Driving ◽  
3D City Models ◽  
Semantic Enrichment ◽  
Simulation Engine ◽  
Global Accuracy ◽  
Model Database ◽  
City Models

Abstract. Nowadays, the number of connected devices providing unstructured data is rapidly rising. These devices acquire data with a temporal and spatial resolution at an unprecedented level creating an influx of geoinformation which, however, lacks semantic information. Simultaneously, structured datasets like semantic 3D city models are widely available and assure rich semantics and high global accuracy but are represented by rather coarse geometries. While the mentioned downsides curb the usability of these data types for nowadays’ applications, the fusion of both shall maximize their potential. Since testing and developing automated driving functions stands at the forefront of the challenges, we propose a pipeline fusing structured (CityGML and HD Map datasets) and unstructured datasets (MLS point clouds) to maximize their advantages in the automatic 3D road space models reconstruction domain. The pipeline is a parameterized end-to-end solution that integrates segmentation, reconstruction, and modeling tasks while ensuring geometric and semantic validity of models. Firstly, the segmentation of point clouds is supported by the transfer of semantics from a structured to an unstructured dataset. The distinction between horizontal- and vertical-like point cloud subsets enforces a further segmentation or an immediate refinement while only adequately depicted models by point clouds are allowed. Then, based on the classified and filtered point clouds the input 3D model geometries are refined. Building upon the refinement, the semantic enrichment of the 3D models is presented. The deployment of a simulation engine for automated driving research and a city model database tool underlines the versatility of possible application areas.

Collaborative 3D Modeling

2016 ◽  
Vol 5 (3) ◽  
pp. 47-67 ◽  
Author(s):  
Rafika Hajji ◽  
Roland Billen
Keyword(s):  
3D Modeling ◽  
Building Model ◽  
3D Data ◽  
3D Building Model ◽  
Promising Solution ◽  
New Vision ◽  
Definition Of ◽  
2D Data ◽  
City Models

The need of 3D city models increases day by day. However, 3D modeling still faces some impediments to be generalized. Therefore, new solutions such as collaboration should be investigated. The paper presents a new vision of collaboration applied on 3D modeling through the definition of the concept of a 3D collaborative model. The paper highlights basic questions to be considered for the definition and the development of that model then argues the importance of reuse of 2D data as a promising solution to reconstruct 3D data and to upgrade to integrated 3D solutions in the future. This idea is supported by a case study, to demonstrate how 2D/2.5D data collected from different providers in Walloon region in Belgium can be integrated and reengineered to match the specifications of a 3D building model compatible with the CityGML standard.

scholarly journals A Method for the Automated Construction of 3D Models of Cities and Neighborhoods from Official Cadaster Data for Solar Analysis

2021 ◽  
Vol 13 (11) ◽  
pp. 6028
Author(s):  
Carlos Beltran-Velamazan ◽  
Marta Monzón-Chavarrías ◽  
Belinda López-Mesa
Keyword(s):  
3D Model ◽  
3D Models ◽  
Automatic Method ◽  
Time Saving ◽  
Automatic Construction ◽  
3D City Models ◽  
Solar Analysis ◽  
Solar Access ◽  
Short Time ◽  
City Models

3D city models are a useful tool to analyze the solar potential of neighborhoods and cities. These models are built from buildings footprints and elevation measurements. Footprints are widely available, but elevation datasets remain expensive and time-consuming to acquire. Our hypothesis is that the GIS cadastral data can be used to build a 3D model automatically, so that generating complete cities 3D models can be done in a short time with already available data. We propose a method for the automatic construction of 3D models of cities and neighborhoods from 2D cadastral data and study their usefulness for solar analysis by comparing the results with those from a hand-built model. The results show that the accuracy in evaluating solar access on pedestrian areas and solar potential on rooftops with the automatic method is close to that from the hand-built model with slight differences of 3.4% and 2.2%, respectively. On the other hand, time saving with the automatic models is significant. A neighborhood of 400,000 m2 can be built up in 30 min, 50 times faster than by hand, and an entire city of 967 km2 can be built in 8.5 h.

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 AN EXTRACTION APPROACH OF THE TOP-BOUNDED SPACE FORMED BY BUILDINGS FOR PEDESTRIAN NAVIGATION

2018 ◽  
Vol IV-4 ◽  
pp. 247-254 ◽  
Author(s):  
J. Yan ◽  
A. A. Diakité ◽  
S. Zlatanova
Keyword(s):  
Indoor Environment ◽  
Three Dimensional ◽  
3D Models ◽  
Rapid Expansion ◽  
Navigation Systems ◽  
Connected Space ◽  
3D City Models ◽  
Pedestrian Navigation ◽  
Bounded Space ◽  
City Models

<p><strong>Abstract.</strong> The navigation of pedestrians can be regarded as their movements from one unoccupied space to another unoccupied and connected space. These movements generally occur in three types of environments: indoor, outdoor, and semi-bounded (top-bounded, and/or side-bounded) spaces. While the two former types of spaces are subject to most of the attention, the latter (semi-bounded) also presents a valuable impact on the navigation behaviour. For example, top-bounded environments (e.g. roofs, shelters, etc.) are very popular for pedestrian navigation since a top structure can offer protection from harsh weather, rain, or strong sun. However, such semibounded spaces are completely missing in current navigation models and systems. This is partly explained by the fact that modelling the space, which is by defining a three-dimensional boundless and extensible component (mainly out of the indoor environment), is a very challenging task. In this paper, we propose a structure-based approach for top-bounded space extraction in the built environment, relying on 3D models. Thanks to the rapid expansion and availability of 3D city models, our approach can help to account for such type of spaces in 3D pedestrian navigation systems.</p>

scholarly journals INTEGRATED USE OF REMOTE SENSED DATA AND NUMERICAL CARTOGRAPHY FOR THE GENERATION OF 3D CITY MODELS

2018 ◽  
Vol XLII-2 ◽  
pp. 97-102 ◽  
Author(s):  
G. Bitelli ◽  
V. A. Girelli ◽  
A. Lambertini
Keyword(s):  
Large Scale ◽  
Point Clouds ◽  
3D Models ◽  
Geospatial Data ◽  
Aerial Images ◽  
Public Authorities ◽  
3D City Models ◽  
3D Point Clouds ◽  
Emilia Romagna Region ◽  
City Models

3D city models are becoming increasingly popular and important, because they constitute the base for all the visualization, planning, management operations regarding the urban infrastructure. These data are however not available in the majority of cities: in this paper, the possibility to use geospatial data of various kinds with the aim to generate 3D models in urban environment is investigated.<br> In 3D modelling works, the starting data are frequently the 3D point clouds, which are nowadays possible to collect by different sensors mounted on different platforms: LiDAR, imagery from satellite, airborne or unmanned aerial vehicles, mobile mapping systems that integrate several sensors. The processing of the acquired data and consequently the obtainability of models able to provide geometric accuracy and a good visual impact is limited by time, costs and logistic constraints.<br> Nowadays more and more innovative hardware and software solutions can offer to the municipalities and the public authorities the possibility to use available geospatial data, acquired for diverse aims, for the generation of 3D models of buildings and cities, characterized by different level of detail.<br> In the paper two cases of study are presented, both regarding surveys carried out in Emilia Romagna region, Italy, where 2D or 2.5D numerical maps are available. The first one is about the use of oblique aerial images realized by the Municipality for a systematic documentation of the built environment, the second concerns the use of LiDAR data acquired for other purposes; in the two tests, these data were used in conjunction with large scale numerical maps to produce 3D city models.

scholarly journals 3D CITY MODELS FOR SUPPORTING SIMULATIONS IN CITY DENSIFICATIONS

2021 ◽  
Vol XLVI-4/W4-2021 ◽  
pp. 73-77
Author(s):  
L. Harrie ◽  
J. Kanters ◽  
K. Mattisson ◽  
P. Nezval ◽  
P.-O. Olsson ◽  
...  
Keyword(s):  
Urban Areas ◽  
Planning Process ◽  
Model Design ◽  
3D City Models ◽  
3D City Model ◽  
Neighbourhood Level ◽  
City Model ◽  
Good Living ◽  
Research Questions ◽  
City Models

Abstract. In order to meet the increasing needs of housing and services in urban areas, cities are densified. When densifying a city, it is important to provide good living conditions while maintaining a low environmental impact. To ensure this, the urban planning process should include simulations of e.g. noise and daylight conditions. In this paper we describe a newly started projected directed towards the need for quality-assured and harmonised input data to the simulations, in the form of 3D city models. The first part of the paper includes the background and research questions of the project and in the second part a tool for daylight simulations on neighbourhood level is introduced, a tool that will be utilized for evaluating the 3D city model design.

Sign in / Sign up

Export Citation Format

Share Document