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.

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 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.

Challenges of Semantic 3D City Models

2015 ◽  
Vol 4 (2) ◽  
pp. 68-76 ◽  
Author(s):  
Roland Billen ◽  
Anne-Françoise Cutting-Decelle ◽  
Claudine Métral ◽  
Gilles Falquet ◽  
Sisi Zlatanova ◽  
...  
Keyword(s):  
Urban Development ◽  
Sustainable Urban Development ◽  
Cost Action ◽  
3D City Models ◽  
Semantic Enrichment ◽  
Technical Paper ◽  
Information Models ◽  
Urban Models ◽  
The Cost ◽  
City Models

This technical paper is a contribution to the identification of current challenges of semantic 3D city models. They are presented in four parts, namely 3D enriched city models and their connection with urban information models and smartcities, urban models integration, urban analyses and data. This work is an output of the COST Action TU0801 “Semantic Enrichment of 3D city models for sustainable urban development”.

scholarly journals 3D CITY MODELS FOR URBAN MINING: POINT CLOUD BASED SEMANTIC ENRICHMENT FOR SPECTRAL VARIATION IDENTIFICATION IN HYPERSPECTRAL IMAGERY

2020 ◽  
Vol V-4-2020 ◽  
pp. 223-230
Author(s):  
P. A. Ruben ◽  
R. Sileryte ◽  
G. Agugiaro
Keyword(s):  
Point Cloud ◽  
Building Materials ◽  
Hyperspectral Imagery ◽  
Region Growing ◽  
Accurate Information ◽  
Spectral Variation ◽  
Urban Mining ◽  
3D City Models ◽  
Semantic Enrichment ◽  
City Models

Abstract. Urban mining aims at reusing building materials enclosed in our cities. Therefore, it requires accurate information on the availability of these materials for each separate building. While recent publications have demonstrated that such information can be obtained using machine learning and data fusion techniques applied to hyperspectral imagery, challenges still persist. One of these is the so-called ’salt-and-pepper noise’, i.e. the oversensitivity to the presence of several materials within one pixel (e.g. chimneys, roof windows). For the specific case of identifying roof materials, this research demonstrates the potential of 3D city models to identify and filter out such unreliable pixels beforehand. As, from a geometrical point of view, most available 3D city models are too generalized for this purpose (e.g. in CityGML Level of Detail 2), semantic enrichment using a point cloud is proposed to compensate missing details. So-called deviations are mapped onto a 3D building model by comparing it with a point cloud. Seeded region growing approach based on distance and orientation features is used for the comparison. Further, the results of a validation carried out for parts of Rotterdam and resulting in KHAT values as high as 0.7 are discussed.

scholarly journals A 3D CAMPUS APPLICATION BASED ON CITY MODELS AND WEBGL

2018 ◽  
Vol XLII-5 ◽  
pp. 161-165 ◽  
Author(s):  
M. Buyukdemircioglu ◽  
S. Kocaman
Keyword(s):  
Semantic Information ◽  
Geographical Information ◽  
Data Types ◽  
3D City Models ◽  
Gis Applications ◽  
Technological Developments ◽  
Gis Environment ◽  
Virtual Platform ◽  
Application Fields ◽  
City Models

<p><strong>Abstract.</strong> In parallel with the technological developments, the conventional ways of mapping and the presentation of the geospatial data have changed significantly. 3D city models including the digital terrain models (DTMs) have become important for many application fields, such as simulation and visualization tasks for navigation, urban planning, environmental monitoring, disaster management, etc. Although currently most 3D city models are employed for visualization purposes, their application areas are increasing continuously. The presentation of these models on the web is also becoming more common than before while overcoming the performance issues with newer data types and functionalities. The biggest advantage of using web browsers is that they can be accessed everywhere without any additional software requirements. Therefore, the tools for web-based implementations of virtual globes, which allow users to navigate their data in 3D, have been available with greater numbers of functionality they offer. Online virtual web globes provide a good base for the 3D Geographical Information System (GIS) applications as well. 3D city models have also become virtual environments where different spatial queries and analysis can be performed. As a part of a 3D WebGIS, a city model enriched with semantic information provides a virtual platform for decision makers and allows realistic simulations for planning. The main aims of this study are to develop a prototype of a 3D GIS environment for Hacettepe University Beytepe campus, including 3D building geometries enriched with semantic information and a high resolution DTM; and to design a web interface using an open source virtual globe.</p>

scholarly journals Computing and monitoring potential of public spaces by shading analysis using 3d lidar data and advanced image analysis

2015 ◽  
Vol XL-7/W3 ◽  
pp. 743-750 ◽  
Author(s):  
A. Zwolinski ◽  
M. Jarzemski
Keyword(s):  
Tall Buildings ◽  
Public Spaces ◽  
Lidar Data ◽  
Data Types ◽  
3D City Models ◽  
European Cities ◽  
Computer Environment ◽  
Definition Of ◽  
3D Lidar ◽  
City Models

The paper regards specific context of public spaces in “shadow” of tall buildings located in European cities. Majority of tall buildings in European cities were built in last 15 years. Tall buildings appear mainly in city centres, directly at important public spaces being viable environment for inhabitants with variety of public functions (open spaces, green areas, recreation places, shops, services etc.). All these amenities and services are under direct impact of extensive shading coming from the tall buildings. The paper focuses on analyses and representation of impact of shading from tall buildings on various public spaces in cities using 3D city models. Computer environment of 3D city models in cityGML standard uses 3D LiDAR data as one of data types for definition of 3D cities. The structure of cityGML allows analytic applications using existing computer tools, as well as developing new techniques to estimate extent of shading coming from high-risers, affecting life in public spaces. These measurable shading parameters in specific time are crucial for proper functioning, viability and attractiveness of public spaces – finally it is extremely important for location of tall buildings at main public spaces in cities. The paper explores impact of shading from tall buildings in different spatial contexts on the background of using cityGML models based on core LIDAR data to support controlled urban development in sense of viable public spaces. The article is prepared within research project 2TaLL: Application of 3D Virtual City Models in Urban Analyses of Tall Buildings, realized as a part of Polish-Norway Grants.

scholarly journals Improving trajectory estimation using 3D city models and kinematic point clouds

2021 ◽  
Author(s):  
Lukas Lucks ◽  
Lasse Klingbeil ◽  
Lutz Plümer ◽  
Youness Dehbi
Keyword(s):  
Point Clouds ◽  
Trajectory Estimation ◽  
3D City Models ◽  
Kinematic Point ◽  
City Models

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.

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