CityGML in the Integration of BIM and the GIS: Challenges and Opportunities

CityGML (City Geography Markup Language) is the most investigated standard in the integration of building information modeling (BIM) and the geographic information system (GIS), and it is essential for digital twin and smart city applications. The new CityGML 3.0 has been released for a while, but it is still not clear whether its new features bring new challenges or opportunities to this research topic. Therefore, the aim of this study is to understand the state of the art of CityGML in BIM/GIS integration and to investigate the potential influence of CityGML3.0 on BIM/GIS integration. To achieve this aim, this study used a systematic literature review approach. In total, 136 papers from Web of Science (WoS) and Scopus were collected, reviewed, and analyzed. The main findings of this review are as follows: (1) There are several challenging problems in the IFC-to-CityGML conversion, including LoD (Level of Detail) mapping, solid-to-surface conversion, and semantic mapping. (2) The ‘space’ concept and the new LoD concept in CityGML 3.0 can bring new opportunities to LoD mapping and solid-to-surface conversion. (3) The Versioning module and the Dynamizer module can add dynamic semantics to the CityGML. (4) Graph techniques and scan-to-BIM offer new perspectives for facilitating the use of CityG

A 3D Hellenic archaeological cadastre based on LADM

Εθνικό Μετσόβιο Πολυτεχνείο--Μεταπτυχιακή Εργασία. Διεπιστημονικό-Διατμηματικό Πρόγραμμα Μεταπτυχιακών Σπουδών (Δ.Π.Μ.Σ.) “Γεωπληροφορική

EuroSDR GeoBIM project a study in Europe on how to use the potentials of BIM and GEO data in practice

In both the Geo and BIM domains, it is widely acknowledged that the integration of geo-data and BIM-data is beneficial and a crucial step in facing the multi-disciplinary challenges of our built environment. The result of this integration - broadly termed as GeoBIM - has a range of potential uses from district study to road safety. However, from the data perspective, this integration raises the question of how to integrate very detailed design and construction data from the BIM domain with contextual geospatial data (both 2D and 3D) that model a very diverse range of aspects of the wider built and natural environment. This paper reports work carried out during the second phase of the EuroSDR GeoBIM project, which sets out to understand the general status of GeoBIM across Europe with particular focus from a National Mapping and Cadastral Agency perspective. The first phase of the project reviewed the current status of GeoBIM in participating countries and identified the need for specific detailed use cases to overcome both the lack of awareness and the lack of understanding of the potential of GeoBIM. We present both an update on the current status of GeoBIM, and additional details of one of the selected use cases relating to planning/development permits. For the latter, we have been able to develop a detailed workflow highlighting specific data exchange points within the process to issue a development permit, allowing a more in-depth identification of both the roles and data needs at each stage

3D visualization of cadastre : assessing the suitability of visual variables and enhancement techniques in the 3D model of condominium property units

La visualisation 3D de données cadastrales a été exploitée dans de nombreuses études, car elle offre de nouvelles possibilités d’examiner des situations de supervision verticale des propriétés. Les chercheurs actifs dans ce domaine estiment que la visualisation 3D pourrait fournir aux utilisateurs une compréhension plus intuitive d’une situation où des propriétés se superposent, ainsi qu’une plus grande capacité et avec moins d’ambiguïté de montrer des problèmes potentiels de chevauchement des unités de propriété. Cependant, la visualisation 3D est une approche qui apporte de nombreux défis par rapport à la visualisation 2D. Les précédentes recherches effectuées en cadastre 3D, et qui utilisent la visualisation 3D, ont très peu enquêté l’impact du choix des variables visuelles (ex. couleur, style) sur la prise de décision. Dans l’optique d'améliorer la visualisation 3D de données cadastres, cette thèse de doctorat examine l’adéquation du choix des variables visuelles et des techniques de rehaussement associées afin de produire un modèle de condominium 3D optimal, et ce, en fonction de certaines tâches spécifiques de visualisation. Les tâches visées sont celles dédiées à la compréhension dans l’espace 3D des limites de propriété du condominium. En ce sens, ce sont principalement des tâches notariales qui ont été ciblées. De plus, cette thèse va mettre en lumière les différences de l’impact des variables visuelles entre une visualisation 2D et 3D. Cette thèse identifie dans un premier temps un cadre théorique pour l'interprétation des variables visuelles dans le contexte d’une visualisation 3D et de données cadastrales au regard d’une revue de littéraire. Dans un deuxième temps, des expérimentations ont été réalisées afin de mettre à l’épreuve la performance des variables visuelles (ex. couleur, valeur, texture) et des techniques de rehaussement (transparence, annotation, déplacement). Trois approches distinctes ont été utilisées : 1) discussion directe avec des personnes œuvrant en géomatique, 2) entrevue face à face avec des notaires et 3) questionnaire en ligne avec des groupes ciblés. L’utilisabilité mesurée en termes d’efficacité, d’efficience et de degré de satisfaction a servi aux comparaisons des expérimentations. Les principaux résultats de cette recherche sont : 1) Une liste de tâches visuelles notariales utiles à la délimitation des unités de propriété dans le contexte de la visualisation 3D de condominium ; 2) Des recommandations quant à l'adéquation de huit variables visuelles et de trois techniques de rehaussement afin d’optimiser la réalisation d’un certain nombre de tâches notariales ; 3) Une analyse comparative de la performance de ces variables entre une visualisation 2D et 3D.3D visualization is being widely used in GIS (geographic information system) and CAD (computer-aided design) applications. It has also been introduced in cadastre studies to better communicate overlaps to the viewer, where the property units vertically stretch over or cover one part of the land parcel. Researchers believe that 3D visualization could provide viewers with a more intuitive perception, and it has the capability to demonstrate overlapping property units in condominiums unambiguously. However, 3D visualization has many challenges compared with 2D visualization. Many cadastre researchers adopted 3D visualization without thoroughly investigating the potential users, the visual tasks for decision-making, and the appropriateness of their representation design. Neither designers nor users may be aware of the risk of producing an inadequate 3D visualization, especially in an era when 3D visualization is relatively novel in the cadastre domain. With a general aim to improve the 3D visualization of cadastre data, this dissertation addresses the design of the 3D cadastre model from a graphics semiotics viewpoint including visual variables and enhancement techniques. The research questions are, firstly, what is the suitability of the visual variables and enhancement techniques in the 3D cadastre model to support the intended users' decision-making goal of delimitating condominium property units, and secondly, what are the perceptual properties of visual variables in 3D visualization compared with 2D visualization? This dissertation firstly identifies the theoretical framework for the interpretation of visual variables in 3D visualization as well as cadastre-related knowledge with literature review. Then, we carry out a preliminary evaluation of the feasibility of visual variables and enhancement techniques in a form of an expert-group review. With the result of the preliminary evaluation, this research then performs the hypothetico-deductive scientific approach to establishing a list of hypotheses to be validated by empirical tests regarding the suitability of visual variables and enhancement techniques in a cartographic representation of property units in condominiums for 3D visualization. The evaluation is based on the usability specification, which contains three measurements: effectiveness, efficiency, and preference. Several empirical tests are conducted with cadastral users in the forms of face-to-face interviews and online questionnaires, followed by statistical analysis. Size, shape, brightness, saturation, hue, orientation, texture, and transparency are the most discussed and used visual variables in existing cartographic research and implementations; thus, these eight visual variables have been involved in the tests. Their perceptual properties exhibited in the empirical test with concrete 3D models in this work are compared with those in a 2D visualization, which is derived from a literature-based synthesis. Three enhancement techniques, including labeling, 3D explosion, and highlighting, are tested as well. There are three main outcomes of this work. First, we established a list of visual tasks adapted to notaries for delimiting property units in the context of 3D visualization of condominium cadastres. Second, we describe the suitability of eight visual variables (Size, Shape, Brightness, Saturation, Hue, Orientation, Texture, and Transparency) of the property units and three enhancement techniques (labeling, 3D explosion and highlighting) in the context of 3D visualisation of condominium property units, based on the usability specification for delimitating visual tasks. For example, brightness only shows good performance in helping users distinguish private and common parts in the context of 3D visualization of property units in condominiums. As well, color hue and saturation are effective and preferable. The third outcome is a statement of the perceptual properties’ differences of visual variables between 3D visualization and 2D visualization. For example, according to Bertin (1983)’s definition, orientation is associative and selective in 2D, yet it does not perform in a 3D visualization. In addition, 3D visualization affects the performance of brightness, making it marginally dissociative and selective

3D Cadastre visualization and dissemination: Most recent progresses and future directions

The 3D Cadastre has been investigated from many viewpoints (including legal, organizational and technical). However, to date little research has focused specifically on visualizationrelated aspects despite the value-added of the third dimension. The paper first proposes an overview of progress made in the last five years in 3D cadastral visualization. The authors then summarize discussions at the 2014 3D Cadastre workshop regarding future research and development on the topic. This synthesis is complemented by a broad review of the most recent advances in 3D visualization beyond the 3D cadastral domain, with the goal of providing a number of important directions for further work, allowing researchers, developers and users to consolidate their respective activities, and encouraging collaboration

Integration of historical GIS data in a HBIM system

The integration between BIM (Building Information Modeling) and GIS (Geographic Information System) is currently a highly debated research topic. However, the effective integration of the two workflows in a unique information system is still an open research field, especially when dealing with Cultural Heritage (CH). The paper describes an ongoing research on the development of a web information system able to integrate BIM and GIS data, with particular focus on the analysis of the historicized city and its main buildings over time. Three main aspects, in particular, are considered more relevant: (i) conceptual data organization to integrate GIS and BIM in a single environment; (ii) integration of data belonging to different historical periods for analyses over time (4D); (iii) integration into the system of datasets already structured in pre-existing HGIS and HBIM. Most (if not all) of the attributes must be linked with both 2D and 3D entities. The system should be queryable and with the possibility to edit the information regardless of the actual focus of the current user, either if he is more BIM or GIS oriented. This is one of the main requirement for the system not to be just a simple viewer of BIM and GIS data in a unique software environment. The system can manage, from a spatial point of view, different scales of detail, allowing the connection between data from the architectural scale to the territorial one and, from a temporal point of view, data belonging to different periods. All these features have been designed to meet, in particular, the requirements of CH and realize a Historical BIM-GIS system. Besides, the web architecture allows sharing information even between actors with different digital skills, without the need for specific software installed, and ensures portability and access from mobile devices

3D Cadastres Best Practices, Chapter 5: Visualization and New Opportunities

This paper proposes a discussion on opportunities offered by 3D visualization to improve the understanding and the analysis of cadastre data. It first introduce the rationale of having 3D visualization functionalities in the context of cadastre applications. Second the publication outline some basic concepts in 3D visualization. This section specially addresses the visualization pipeline as a driven classification schema to understand the steps leading to 3D visualization. In this section is also presented a brief review of current 3D standards and technologies. Next is proposed a summary of progress made in the last years in 3D cadastral visualization. For instance, user’s requirement, data and semiotics, and platforms are highlighted as main actions performed in the development of 3D cadastre visualization. This review could be perceived as an attempt to structure and emphasise the best practices in the domain of 3D cadastre visualization and as an inventory of issues that still need to be tackled. Finally, by providing a review on advances and trends in 3D visualization, the paper initiates a discussion and a critical analysis on the benefit of applying these new developments to cadastre domain. This final section discusses about enhancing 3D techniques as dynamic transparency and cutaway, 3D generalization, 3D visibility model, 3D annotation, 3D data and web platform, augmented reality, immersive virtual environment, 3D gaming, interaction techniques and time

Towards a National 3D Mapping Product for Great Britain

Knowing where something happens and where people are located can be critically important to understand issues ranging from climate change to road accidents, crime, schooling, transport and much more. To analyse these spatial problems, two-dimensional representations of the world, such as paper or digital maps, have traditionally been used. Geographic information systems (GIS) are the tools that enable capture, modelling, storage, retrieval, sharing, manipulation, analysis, and presentation of geographically referenced data. Three-dimensional geographic information (3D GI) is data that can represent real-world features as objects in 3D space. 3D GI offers additional functionality not possible in 2D, including analysing and querying volume, visibility, surface and sub-surface, and shadowing. This thesis contributes to the understanding of user requirements and other data related considerations in the production of 3D geographic information at a national level. The study promotes Ordnance Survey’s efforts in developing a 3D geographic product through: (1) identifying potential applications; (2) analysing existing 3D city modelling approaches; (3) eliciting and formalising user requirements; (4) developing metrics to describe the usefulness of 3D data and; (5) evaluating the commerciality of 3D GI. A review of current applications of 3D showed that visualisation dominated as the main use, allowing for better communication, and supporting decision-making processes. Reflecting this, an examination of existing 3D city models showed that, despite the varying modelling approaches, there was a general focus towards accurate and realistic geometric representation of the urban environment. Web-based questionnaires and semi-structured interviews revealed that while some applications (e.g. subsurface, photovoltaics, air and noise quality) lead the field with a high adoption of 3D, others were laggards due to organisational inertia (e.g. insurance, facilities management). Individuals expressed positive views on the use of 3D, but still struggled to justify the value and business case. Simple building geometry coupled with non-building thematic classes was perceived to be most useful by users. Several metrics were developed to quantify and compare the characteristics of thirty-three 3D datasets. Results showed that geometry-based metrics such as minimum feature length or Euler characteristic can be used to provide additional information as part of fitness-for-purpose evaluations. The metrics can also contribute to quality control during data production. An investigation into the commercial opportunities explored the economic value of 3D, the market size of 3D data in Great Britain, as well as proposed a number of opportunities within the wider business context of Ordnance Survey

3D cadastral complexities in dense urban areas of developing countries: case studies from Delhi and satellite towns

Cadastral systems based on 2D spatial representation have served land administration and property management well for centuries. In India, the basic unit of the cadastral record is the land parcel, which is known as plot. Maintenance of land records with ownership; assessment of tax on the property and tax collection is the responsibility of district authorities. Historically, Delhi has been preferred as a capital by different rulers from various dynasties and invaders coming from different partTS03B_ezeomedo_igbokwe_6421s of the world even before 15th century. As in many densely populated areas even the early developments included 3D solutions, both below and above the surface. In the early days these were rather exceptions, but the 3D use of space has only been increased afterwards due to the continuously growing needs for space and the increased (civil) engineering and construction capabilities. In the early decades after gaining independence in 1947, Delhi rapidly began taking shape of a metro city due to large number of refugees coming from Pakistan who changed the landscape of entire Delhi. By the starting of 21st Century, Delhi had started growing rapidly in terms of population and infrastructure development. This rapid expansion in Delhi and immediate neighbouring cities of Noida and Gurgaon found the land administration agencies of these cities unprepared to deal with this rapidly changing land market. Delhi is managed by various land management agencies. Some have a major role to play in planning and development of the land like Delhi Development Authority while others focus more execution and maintenance like municipal corporations. Delhi does have a long-standing system of Deed registration but have no central registry. In general, records of land held by governmental agencies are maintained by each individual agency. The current paper aims to study the multi-stakeholding urban area locations in Delhi and around where (infrastructural) changes are creating the complex land management situations for the authorities involved. Three cases, mainly related to buildings and apartments, are presented in brief to highlight the different aspects of 3D spatial complexities involved while the forth case study is mode elaborated and focusing on multi-infrastructure (utility) networks in one single area. General Spatial Dimensions for each case are discussed focusing on geometric aspects in vertical and horizontal space below or above surface. As a specific focus, the spatial dimensions are discussed within the context of Land Administration Domain Model (LADM) Spatial Unit Package context

Integrated HBIM-GIS Models for Multi-Scale Seismic Vulnerability Assessment of Historical Buildings

The complexity of historical urban centres progressively needs a strategic improvement in methods and the scale of knowledge concerning the vulnerability aspect of seismic risk. A geographical multi-scale point of view is increasingly preferred in the scientific literature and in Italian regulation policies, that considers systemic behaviors of damage and vulnerability assessment from an urban perspective according to the scale of the data, rather than single building damage analysis. In this sense, a geospatial data sciences approach can contribute towards generating, integrating, and making virtuous relations between urban databases and emergency-related data, in order to constitute a multi-scale 3D database supporting strategies for conservation and risk assessment scenarios. The proposed approach developed a vulnerability-oriented GIS/HBIM integration in an urban 3D geodatabase, based on multi-scale data derived from urban cartography and emergency mapping 3D data. Integrated geometric and semantic information related to historical masonry buildings (specifically the churches) and structural data about architectural elements and damage were integrated in the approach. This contribution aimed to answer the research question supporting levels of knowledge required by directives and vulnerability assessment studies, both about the generative workflow phase, the role of HBIM models in GIS environments and toward user-oriented webGIS solutions for sharing and public use fruition, exploiting the database for expert operators involved in heritage preservation