Determining geometric primitives for a 3D GIS : easy as 1D, 2D, 3D?

Acquisition techniques such as photo modelling, using SfM-MVS algorithms, are being applied increasingly in several fields of research and render highly realistic and accurate 3D models. Nowadays, these 3D models are mainly deployed for documentation purposes. As these data generally encompass spatial data, the development of a 3D GIS would allow researchers to use these 3D models to their full extent. Such a GIS would allow a more elaborate analysis of these 3D models and thus support the comprehension of the objects that the features in the model represent. One of the first issues that has to be tackled in order to make the resulting 3D models compatible for implementation in a 3D GIS is the choice of a certain geometric primitive to spatially represent the input data. The chosen geometric primitive will not only influence the visualisation of the data, but also the way in which the data can be stored, exchanged, manipulated, queried and understood. Geometric primitives can be one-, two- and three-dimensional. By adding an extra dimension, the complexity of the data increases, but the user is allowed to understand the original situation more intuitively. This research paper tries to give an initial analysis of 1D, 2D and 3D primitives in the framework of the integration of SfM-MVS based 3D models in a 3D GIS

Integrazione di database spaziali multiscala in ambito urbano

An information data infrastructure is one of the key to assure efficiency and sustainability for urban processes management. In this field spatial data management plays a central role with a focus on thematic and geometric integration, multi-scale modelling and flexibility to specific needs. These goals can be achieved through the provision of specific standards and tools for data modelling and information retrieving. The widening of the application fields of GIS to the architectural representations of the cultural heritage documentation and consequently the 3D data management support are two of the major issues for filling the gap between the CAD and GIS and their cultural and productive background. Her will be presented some preliminary issues of a test on spatal data integration in a XML based data structure following the OGC's CityGML specifications. The model implementation will focus on the multiscale and multiview modelling tools of standard as a first stepo for the management of a 3D spatial database through XML based application tool

TechTip: IAPAD

The Integrated Approaches to Participatory Development (IAPAD) programme has developed Participatory 3D Modelling (P3DM), a community-based tool that merges GIS-generated data, local knowledge and traditional spatial information (cognitive maps) to produce a 3D relief model. The model provides a user-friendly and relatively accurate tool for spatial research, planning and management, and serves as focal point for sharing information. The IAPAD website offers access to various P3DM applications and project case studies, as well as the P3DM manual, a participatory mapping toolbox and modelling tips. http://www.iapad.org/ www.iapad.org.The Integrated Approaches to Participatory Development (IAPAD) programme has developed Participatory 3D Modelling (P3DM), a community-based tool that merges GIS-generated data, local knowledge and traditional spatial information (cognitive maps) to produ

A REVIEW OF 3D GIS FOR USE IN CREATING VIRTUAL HISTORIC DUBLIN

This paper illustrates how BIM integration with GIS is approached as part of the workflow in creating Virtual Historic Dublin. A design for a WEB based interactive 3D model of historic buildings and centres in Dublin City (Virtual Historic Dublin City) paralleling smart city initiates is now under construction and led by the National Monuments at the Office of Public Works in Ireland. The aim is to facilitate the conservation and maintenance of historic infrastructure and fabric and the dissemination of knowledge for education and cultural tourism using an extensive Historic Building Information Model. Remote sensing data is now processed with greater ease to create 3D intelligent models in Historic BIM. While the use of remote sensing, HBIM and game engine platforms are the main applications used at present, 3D GIS has potential to form part of the workflow for developing the Virtual Historic City. 2D GIS is now being replaced by 3D spatial data allowing more complex analysis to be carried out, 3D GIS can define and depict buildings, urban rural centres in relation to their geometry topological, semantic and visualisation properties. The addition of semantic attributes allows complex analysis and 3D spatial queries for modelling city and urban elements. This analysis includes fabric and structural elements of buildings, relief, vegetation, transportation, water bodies, city furniture and land use

Geological spatial database and visualization modelling methods for mining groundwater

Abstract It is one of the research hotspot and difficult of the mining groundwater three-dimensional information and visualization for hydroinformatics, to solve the problem of groundwater hydrology geological spatial database and visualization of 3D geological modelling, proposed a three-dimensional geological modelling method based on finite difference method, and the mine hydrogeological spatial database, the groundwater survey information database,3D geological modelling based on GIS, groundwater spatial visualization of 3D data model and key algorithms are created. Simulation results show that can realize the hydrogeological space in Yulin area database and 3D visualization of geologic model and spatial hydrological data processing method provides a unified data model, the analysis of hydrological data support a large space, and lays the foundation for the dynamic control model refinement

The design and implementation of a two and three-dimensional triangular irregular network based GIS

It has been realised in the GIS community that most 2D GISs are capable of handling 2D spatial data efficiently, but systems have had less success with 3D spatial data. This is reflected in the current GIS market place where systems which can handle 3D data are hardly available - due to several impediments in implementing such systems. This thesis attempts to address some of the impediments. The impediments which related to spatial data especially data representation, data structuring and data modelling using object-oriented (OO) techniques are the foci of this thesis. OO techniques are utilized because they offer several advantages over the traditional (i.e. structural) techniques in software development. In the aspect of spatial representation, several major representations are investigated, which then lead to identifying an appropriate representation both for 2D and 3D, that is triangular irregular network (TIN) data structures. 2D data is represented by a 2D TIN, and 3D data is represented by a 3D TIN (also called a tetrahedral network or TEN). Several algorithms were developed for the construction of the data structures where procedures such as distance transformation (DT) and Voronoi tessellations were utilized. Besides standard Delaunay triangulations, constrained triangulations were also developed, thus the inclusion of real world objects in the spatial data modelling can be facilitated. Four classes of real world objects are identified (i.e., point, line, surface, and solid objects). For the purpose of spatial data modelling of the four types of objects, a formal data structure (FDS) is utilized

Topologically Consistent Models for Efficient Big Geo-Spatio-Temporal Data Distribution

Geo-spatio-temporal topology models are likely to become a key concept to check the consistency of 3D (spatial space) and 4D (spatial + temporal space) models for emerging GIS applications such as subsurface reservoir modelling or the simulation of energy and water supply of mega or smart cities. Furthermore, the data management for complex models consisting of big geo-spatial data is a challenge for GIS and geo-database research. General challenges, concepts, and techniques of big geo-spatial data management are presented. In this paper we introduce a sound mathematical approach for a topologically consistent geo-spatio-temporal model based on the concept of the incidence graph. We redesign DB4GeO, our service-based geo-spatio-temporal database architecture, on the way to the parallel management of massive geo-spatial data. Approaches for a new geo-spatio-temporal and object model of DB4GeO meeting the requirements of big geo-spatial data are discussed in detail. Finally, a conclusion and outlook on our future research are given on the way to support the processing of geo-analytics and -simulations in a parallel and distributed system environment

Modelling Acoustics in Ancient Maya Cities: Moving Towards a Synesthetic Experience Using GIS & 3D Simulation

Archaeological analyses have successfully employed 2D and 3D tools to measure vision and movement within cityscapes; however, built environments are often designed to invoke synesthetic experiences. GIS and Virtual Reality (VR) now enable archaeologists to also measure the acoustics of ancient spaces. To move toward an understanding of synesthetic experience in ancient Maya cities, we employ GIS and 3D modelling to measure sound propagation and reverberation using the main civic-ceremonial complex in ancient Copán as a case study. For the ancient Maya, sight and sound worked in concert to create ritually-charged atmospheres and architecture served to shape these experiences. Together with archaeological, iconographic, and epigraphic data, acoustic measures help us to (1) examine potential locations of ritual performance and (2) determine spatial placement and capacity of participants in these events. We use an immersive VR headset (Oculus Rift) to integrate vision with spatial sound and sight to facilitate an embodied experience

Integrazione di database spaziali multiscala in ambito urbano

An information data infrastructure is one of the key to assure efficiency and sustainability for urban processes management. In this field spatial data management plays a central role with a focus on thematic and geometric integration, multi-scale modelling and flexibility to specific needs. These goals can be achieved through the provision of specific standards and tools for data modelling and information retrieving. The widening of the application fields of GIS to the architectural representations of the cultural heritage documentation and consequently the 3D data management support are two of the major issues for filling the gap between the CAD and GIS and their cultural and productive background. Her will be presented some preliminary issues of a test on spatal data integration in a XML based data structure following the OGC's CityGML specifications. The model implementation will focus on the multiscale and multiview modelling tools of standard as a first stepo for the management of a 3D spatial database through XML based application tools