3D Spatial Data Research Articles

PENYEDIAAN DATA SPASIAL BANGUNAN DI SEKOLAH VOKASI UGM DALAM SEBUAH BASISDATA 3D

Spatial data supply activities can be carried out with various data inputs and produce various products. One product that stores spatially structured data is spatial database. Spatial database can support storage of height components (3D) of an object, for example a building. The use of 3D spatial database can be very broad and for various fields of application, one of which is the preservation of cultural heritage. This study aims to provide spatial data in the form of a 3D database for building, especially those that have become cultural heritage, within the UGM Vocational School (SV) environment. This activity uses 3D model data from one of the buildings at UGM, the Vocational School library building. Building 3D model is used as input for designing database modeling. The modeling in LOD 3 is then applied using CityGML, including its semantics. The result of the design is then entered into the software to create 3D database. The database analysis stage is performed with several SQL queries to test the research product in the form of the 3D database. Based on the result, 3D spatial data is stored properly using CityGML schema whereas some semantics cannot be accommodated.

Improving the Accuracy of Automatic Reconstruction of 3D Complex Buildings Models from Airborne Lidar Point Clouds

Due to high requirements of variety of 3D spatial data applications with respect to data amount and quality, automatized, efficient and reliable data acquisition and preprocessing methods are needed. The use of photogrammetry techniques—as well as the light detection and ranging (LiDAR) automatic scanners—are among attractive solutions. However, measurement data are in the form of unorganized point clouds, usually requiring transformation to higher order 3D models based on polygons or polyhedral surfaces, which is not a trivial process. The study presents a newly developed algorithm for correcting 3D point cloud data from airborne LiDAR surveys of regular 3D buildings. The proposed approach assumes the application of a sequence of operations resulting in 3D rasterization, i.e., creation and processing of a 3D regular grid representation of an object, prior to applying a regular Poisson surface reconstruction method. In order to verify the accuracy and quality of reconstructed objects for quantitative comparison with the obtained 3D models, high-quality ground truth models were used in the form of the meshes constructed from photogrammetric measurements and manually made using buildings architectural plans. The presented results show that applying the proposed algorithm positively influences the quality of the results and can be used in combination with existing surface reconstruction methods in order to generate more detailed 3D models from LiDAR scanning.

Correction to: Official 3D Spatial Base Data in Germany

The publication of this article unfortunately contained a mistake. A second author was erroneously added and has been removed. The corrected list of authors is given above.

Predicting biomass dynamics at the national extent from digital aerial photogrammetry

The demand for precise mapping and monitoring of forest resources, such as above ground biomass (AGB), has increased rapidly. National accounting and monitoring of AGB requires regularly updated information based on consistent methods. While remote sensing technologies such as airborne laser scanning (ALS) and digital aerial photogrammetry (DAP) have been shown to deliver the necessary 3D spatial data for AGB mapping, the capacity of repeat acquisition, remotely sensed, vegetation structure data for AGB monitoring has received less attention. Here, we use vegetation height models (VHMs) derived from repeat acquisition DAP data (with ALS terrain correction) to map and monitor woody AGB dynamics across Switzerland over 35 years (1983-2017 inclusive), using a linear least-squares regression approach. We demonstrate a consistent relationship between canopy height derived from DAP and field-based NFI measures of woody AGB across four inventory periods. Over the environmentally heterogeneous area of Switzerland, our models have a comparable predictive performance (R2 = 0.54) to previous work predicting AGB based on ALS metrics. Pearson correlation coefficients between measured and predicted changes in woody AGB over time increased with shorter time gaps (< 2 years) between image capture and field-based measurements, ranging between 0.76 and 0.34. A close temporal match between field surveys and remote sensing data acquisition is thus key to reliable mapping and monitoring of AGB dynamics, especially in areas where forest management and natural disturbances trigger relatively fast canopy dynamics. We show that VHMs derived from repeat DAP capture constitute a cost effective and reliable approach to map and monitor changes in woody AGB at a national extent and can provide an important information source for national carbon accounting and monitoring of ecosystem service provisioning.

Experimental Biology 2020 Meeting Abstracts.

NYU School of Medicine recently embarked on a re-design of its anatomy curriculum that decreased the use of cadavers with plastinated specimens. Plastinated models provide an authentic learning experience of the human body, but lack necessary labels outlining important structures. Due to the fragile nature of the specimens, we endeavored to solve the challenge of labeling by developing a digitized supplement and archive of plastinated and pathology specimens. An interdisciplinary team of faculty and multimedia designers at NYU School of Medicine designed and developed electronic resources related to the artistic models and plastinated specimens. Over the course of three months, 60 artistic and plastinated models of different sizes were captured from dozens of angles using a digital camera or an Artec Leo Scanner. The numerous image captures of the plastinated specimens were processed in Agisoft Metashape, a stand-alone software product, that performs photogrammetric processing of digital images and generates 3D spatial data. After Agisoft Metashape exported a complex 3D mesh with a high-resolution texture, anatomy faculty added labels to the digitized 3D anatomy specimens using the Sketchfab web platform. The labeled 3D anatomy models were then uploaded into the Living Anatomy site on NYU School of Medicine's learning management system for students to explore before, during, and after their anatomy lab sessions. Quizzes using these models also were created to help students identify the structures and link them to physiology and clinical scenarios. The digitized 3D models allow students to zoom in, rotate and explore the specimens in a more interactive way, thereby enhancing the process of just observing fragile plastination models. When asked, 84% of students reported that the 3D models of plastinated specimens contributed "very much so" to their learning of anatomical relationships. We will continue to find opportunities for the meaningful integration of these 3D models within the anatomy curriculum as well as into other pre-clerkship and clerkship modules. We will also assess the educational outcomes of the 3D models and, by doing so, will incorporate instructional design into the process.

HyperLabels: Browsing of Dense and Hierarchical Molecular 3D Models.

We present a method for the browsing of hierarchical 3D models in which we combine the typical navigation of hierarchical structures in a 2D environment-using clicks on nodes, links, or icons-with a 3D spatial data visualization. Our approach is motivated by large molecular models, for which the traditional single-scale navigational metaphors are not suitable. Multi-scale phenomena, e. g., in astronomy or geography, are complex to navigate due to their large data spaces and multi-level organization. Models from structural biology are in addition also densely crowded in space and scale. Cutaways are needed to show individual model subparts. The camera has to support exploration on the level of a whole virus, as well as on the level of a small molecule. We address these challenges by employing HyperLabels: active labels that-in addition to their annotational role-also support user interaction. Clicks on HyperLabels select the next structure to be explored. Then, we adjust the visualization to showcase the inner composition of the selected subpart and enable further exploration. Finally, we use a breadcrumbs panel for orientation and as a mechanism to traverse upwards in the model hierarchy. We demonstrate our concept of hierarchical 3D model browsing using two exemplary models from meso-scale biology.

AIRBORNE LIDAR POINT CLOUD CLASSIFICATION BASED ON MULTILEVEL POINT CLUSTER FEATURES

Abstract. Airborne Light Detection And Ranging (LiDAR) has become an important means for efficient and high-precision acquisition of 3D spatial data of large scenes. It has important application value in digital cities and location-based services. The classification and identification of point cloud is the basis of its application, and it is also a hot and difficult problem in the field of geographic information science.The difficulty of LiDAR point cloud classification in large-scale urban scenes is: On the one hand, the urban scene LiDAR point cloud contains rich and complex features, many types of features, different shapes, complex structures, and mutual occlusion, resulting in large data loss; On the other hand, the LiDAR scanner is far away from the urban features, and is like a car, a pedestrian, etc., which is in motion during the scanning process, which causes a certain degree of data noise of the point cloud and uneven density of the point cloud.Aiming at the characteristics of LiDAR point cloud in urban scene.The main work of this paper implements a method based on the saliency dictionary and Latent Dirichlet Allocation (LDA) model for LiDAR point cloud classification. The method uses the tag information of the training data and the tag source of each dictionary item to construct a significant dictionary learning model in sparse coding to expresses the feature of the point set more accurately.And it also uses the multi-path AdaBoost classifier to perform the features of the multi-level point set. The classification of point clouds is realized based on the supervised method. The experimental results show that the feature set extracted by the method combined with the multi-path classifier can significantly improve the cloud classification accuracy of complex city market attractions.

The Digital Twin of the City of Zurich for Urban Planning

Population growth will confront the City of Zurich with a variety of challenges in the coming years, as the increase in the number of inhabitants and jobs will lead to densification and competing land uses. The tasks for the city administration have become more complex, whereas tools and methods are often based on traditional, static approaches while involving a limited number of citizens and stakeholders in relevant decisions. The digital transformation of more and more pieces of the planning and decision-making process will make both increasingly more illustrative, easier to understand and more comprehensible. An important data basis for these processes is the digital twin of the City of Zurich. 3D spatial data and their models transform themes of the city, such as buildings, bridges, vegetation, etc., to the digital world, are being updated when required, and create advantages in digital space. These benefits need to be highlighted and published. An important step in public awareness is the release of 3D spatial data under Open Government Data. This allows the development of applications, the promotion of understanding, and the simplification of the creation of different collaborative platforms. By visualization and analysis of digital prototypes and the demonstration of interactions with the built environment, scenarios can be digitally developed and discussed in decision-making bodies. Questions about the urban climate can be simulated with the help of the digital twin and results can be linked to the existing 3D spatial data. Thus, the 3D spatial data set, the models and their descriptions through metadata become the reference and must be updated according to the requirements. Depending on requirements and questions, further 3D spatial data must be added. The description of the 3D spatial data and their models or the lifecycle management of the digital twin must be carried out with great care. Only in this way, decision processes can be supported in a comprehensible way.

Official 3D Spatial Base Data in Germany

Official 3D Spatial Base Data in Germany

3D Thermal Imaging System with Decoupled Acquisition for Industrial and Cultural Heritage Applications

Three-dimensional thermography is a recent technique—with various fields of application—that consists of combining thermography with 3D spatial data in order to obtain 3D thermograms, high information objects that allow one to overcome some limitations of 2D thermograms, to enhance the thermal monitoring and the detection of abnormalities. In this paper we present an integration methodology that can be applied to merge data acquired from a generic thermal camera and a generic laser scanner, and has the peculiarity of keeping the two devices completely decoupled and independent, so that thermal and geometrical data can be acquired at different times and no rigid link is needed between the two devices. In this way, the stand-alone capability of each device is not affected, and the data fusion is applied only when necessary. In the second part, the real effectiveness of our approach is tested on a 3D-printed object properly designed. Furthermore, one example of an application of our methodology in the cultural heritage field is presented, with an eye to preservation and restoration: the integration is applied to a marble statue called Madonna with the Child, a fine work of the Florentine sculptor Agostino di Duccio (1418–1481). The results suggest that the method can be successfully applicable to a large set of scenarios. However, additional tests are needed to improve the robustness.

Development of process model for Serbian cadastre

Identifying the processes in the cadastre enables understanding the principles on which the cadastre works. Processes in cadastre define the way how the cadastre manages information and what are the prerequisites for the data to be stored in the appropriate data structure. In order to explicitly specify cadastral procedures and workflows to support their automatization, we developed a process model for Serbian cadastre. The main reason for developing the process model is to ensure the framework which will provide possible integration and interoperability with other systems outside traditional cadastral system and between cadastral subsystems themselves. The process model is based on hierarchical decomposition of two basic groups of processes: processes for changing cadastral data and processes for displaying cadastral data. Each group of processes is further decomposed step by step until the workflow of a single process is shown. The developed process model is an abstract model, i.e. it is independent of the implementation. However, in order to instantiate such process model, it is necessary to provide binding of the abstract process model to its underlying implementation. Cadastral registration of spatial units may be beneficial for activities that relay on land administration, such as taxation, spatial planning, obtaining a building permit or legalization of buildings. This relation to the processes under jurisdiction of other organizations justifies the use of cadastral process model and its implementation into SOA environment. Traditionally, cadastral processes include alphanumeric data and 2D spatial data on cadastral maps that contain 2D borders of parcels and buildings. However, recent advancements in 3D technology bring the opportunity to enhance such processes with 3D information. In particular, the aim is to extend current 2D process model to support data maintenance and transactions in the upgrade towards 3D cadastre. Therefore, these 3D data supported workflows are introduced to the process model. For the processes that include 3D information the choice has to be made which specifications will be used and how representations of 3D spatial units will be resolved. In this paper, we first develop an abstract process model of Serbian cadastre. After that, we extend the process model to include 3D information, discuss the options for using the encodings of 3D spatial units (legal spaces) and select buildingSMART openBIM IFC standard for this purpose.

Simulation Analysis of Tsunami Hitting Kaohsiung Cijin: The Application of City Information Model

Although urban planning still relies on 2D plenary map data today, the paper and digital cartographic information and data respectively used in early stage and recent years have a gap with realistic 3D spatial data. In other words, the traditional and conventional cartographic system cannot timely solve problems derived from 3D information integration, complex dimensions and the comprehensive decision-making support system. This study adopts City Information Model (CIM), including an integration of AutoCAD, Google Earth, Sketchup, 3DsMax and aerial photography of unmanned aerial vehicle (UAV), to simulate scenarios of tsunami effects and strategy to respond thereto. The simulation analysis results are expected to be used as a reference to quickly respond to potential tsunamis; plan disaster prevention strategy; and make engineering and construction decisions for the future development of Cijin.

A Hybrid Framework for High-Performance Modeling of Three-Dimensional Pipe Networks

Three-dimensional (3D) pipe network modeling plays an essential part in high performance-based smart city applications. Given that massive 3D pipe networks tend to be difficult to manage and to visualize, we propose in this study a hybrid framework for high-performance modeling of a 3D pipe network, including pipe network data model and high-performance modeling. The pipe network data model is devoted to three-dimensional pipe network construction based on network topology and building information models (BIMs). According to the topological relationships of the pipe point pipelines, the pipe network is decomposed into multiple pipe segment units. The high-performance modeling of 3D pipe network contains a spatial 3D model, the instantiation, adaptive rendering, and combination parallel computing. Spatial 3D model (S3M) is proposed for spatial data transmission, exchange, and visualization of massive and multi-source 3D spatial data. The combination parallel computing framework with GPU and OpenMP was developed to reduce the processing time for pipe networks. The results of the experiments showed that the hybrid framework achieves a high efficiency and the hardware resource occupation is reduced.

Integration of Terrestrial Laser Scanning and UAS Photogrammetry in Geological Studies: Examples from Croatia

Terrestrial laser scanning (TLS) in combination with Unmanned Aircraft System (UAS) and modern computer based photogrammetry is currently the best approach for the acquisition of high-resolution 3D spatial information. Highly realistic 3D spatial data sets are becoming the basis for detailed geological studies, providing a multidisciplinary approach in the study and research of both underground and above ground sites. To emphasize the variety of possible implementations of these state-of-the-art methodologies, four characteristic and yet quite different case studies are presented where such geodetic techniques are successfully employed. The presented case studies demonstrate that TLS and UAS photogrammetry, as non-contact surveying methods, are able to reduce survey time and total project costs. As added value, they provide high-resolution data that can be analyzed in a virtual environment from a sedimentological or structural aspect. Stored digital documentation also allows future multi-temporal spatial data comparison at any timeframe and scale, thus enhancing any target geological data gathering and analyses at the studied sites.

INTEGRATION BETWEEN SURFACE AND SUBSURFACE SPATIAL OBJECTS FOR DEVELOPING OMAN 3D SDI BASED ON THE CITYGML STANDARD

Abstract. The paper investigates the capability to integrate the surface and subsurface 3D spatial objects data structure within the 3D spatial data infrastructure (3D SDI) based on the CityGML standards. In fact, a number of countries around the world have started applying the 3D city models for their planning and infrastructure management. While others are still working toward 3D SDI by using CityGML standards. Moreover, most of these initiatives focus on the surface spatial objects with less interest to model subsurface spatial objects. However, dealing with 3D SDI requires both surface and subsurface spatial objects with clear consideration on the issues and challenges in terms of the data structure. On the other hand, the study has used geospatial tools and databases such as FME, PostgreSQL-PostGIS, and 3D City Database to generate the 3D model and to test the capability for integrating the surface and subsurface 3D spatial objects data structure within the 3D SDI. This paper concludes by describing a framework that aims to integrate surface and subsurface 3D geospatial objects data structure in Oman SDI. The authors believe that there are possible solutions based on CityGML standards for surface and subsurface 3D spatial objects. Moreover, solving the issues in data structure can establish a better vision and open new avenues for the 3D SDI.

SYSTEMS ARCHITECTURE FOR MANAGEMENT OF BIM, 3D GIS AND SENSORS DATA

Abstract. This paper presents a system architecture for structuring and manipulation of Building Information Models (BIM), three-dimensional (3D) geospatial information, point clouds and time series data obtained from sensors. The system consists of four layers including data pre-processing, data structuring and storage, system interface and front-end data manipulation. To enable the integration of different data, a unified UML model is developed. The paper explains all steps of 3D reconstruction, BIM geo-referencing, storage of spatial data and visualisation. Special attention is given to the integration of sensors data. The data model and the system architecture are tested for a university campus. The results demonstrate an approach for BIM-GIS-Sensor integration as part of Precinct Information Modelling (PIM). The system architecture allows for a flexible structuring and manipulation of different spatial data towards managing various 3D spatial and non-spatial data.

PRODUCING AND VISUALIZING A COUNTRY-WIDE 3D DATA REPOSITORY IN FINLAND

Abstract. The amount and the quality of 3D spatial data are growing constantly, but the data is collected and stored in a distributed fashion by various data collecting organizations. This may lead to problems regarding interoperability, usability and availability of the data. Traditionally, national spatial data infrastructures have focused on 2D data, but recently there has been great progress towards introducing also 3D spatial data in governmental services. This paper studies the process of creating a country-wide 3D data repository in Finland and visualizing it for the public by using an open source map application. The 3D spatial data is collected and stored into one national topographic database that provides information for the whole society. The data quality control process is executed with an automated data quality module as a part of the import process to the database. The 3D spatial data is served from the database for the visualization via 3D service and the visualization is piloted in the National Geoportal.

APPLICATION OF THE STEEP SLOPE RISK ASSESSMENT USING THREE DIMENSIONAL INFORMATION DATA

Abstract. A collapse of slope is one of the natural disasters that often occur during the early spring and the rainy season. In order to prevent this kind of disaster, safety monitoring is carried out through risk assessment. This assessment consists of various parameters such as inclination angle and height of the slope, and inspectors evaluate the score using the compass, the laser range finder, and so on. This approach is, however, consumed a lot of the manpower and the time. This study, therefore, aims to evaluate the rapid and accurate steep slope risk by using a terrestrial LiDAR which takes 3 dimensional spatial information data. 3D spatial information data was acquired using the terrestrial LiDAR for steep slopes classified as very unstable slopes. Noise and vegetation of the acquired scan data were removed to generate point cloud data with a rock or mountain model without vegetation. The RMSE of the registration accuracy was 0.0156 m. From the point cloud data, the inclination angle, height, shape, valley, collapse and loss were evaluated. As a result, various risk assessment parameters can be checked at once. In addition, it is expected to be used as basic data for constructing steep slope DB, providing visualization data, and time series analysis in the future.

A Review on 3D Spatial Data Analytics for Building Information Models

Except for various properties, accurate and intuitive 3D representations of building elements and spaces are embedded in Building Information Models (BIMs). Thus, better understanding of spatial features of building elements and spaces is possible, which brings new opportunity in code compliance checking, indoor navigation, visualization, etc. With large amount of fine-grained 3D spatial data collected quickly and continuously, there is an urgent need for new methods to overcome problems like improper spatial expression, insufficient mining and utilization of information that exist in traditional methods. This research reviews state-of-the-art of related research and provides a summary of achievements and challenges in this area. Then, a framework consists of management, analysis, and application of 3D spatial data of BIM and a detailed discussion of each part are proposed, which would give the readers an overview of relevant methods, technologies, and tools. Moreover, potential research directions and open issues for future work are also discussed. The paper enables researchers to get a comprehensive understanding of 3D spatial data analytics of BIM as well as suggestions for future work, and thus makes a solid contribution in this area.

3D Visualization Process and Efficiency Analysis of Geographic Information Based on WebGL

Abstract. With the rapid development of geographic information technology, the web-based 3D visualization technology is constantly updated with the development of computers. However, the traditional 3D geographic data visualization software based on the rich-client model it has significant limitations in the display and analysis of geospatial information and it is difficult to install and use, result in that difficult to meet the application of Geo-dynamic simulation, visual analysis, and collaborative decision-making of the geographic process. In order to show the realism of spatial data more directly, this paper introduces a 3D visualization process design method of geographic information and analyses the 3D data modelling building and visualization efficiency. The process combines multiple data sources are loaded automatically, cross platform, 2D &amp;amp; 3D integration, and make a wider range of customers easily access to the visualization effect of 3D spatial data.