scholarly journals A Full Level-of-Detail Specification for 3D Building Models Combining Indoor and Outdoor Scenes

2018 ◽  
Vol 7 (11) ◽  
pp. 419 ◽  
Author(s):  
Lei Tang ◽  
Lin Li ◽  
Shen Ying ◽  
Yuan Lei
Keyword(s):  
Level Of Detail ◽  
International Standards ◽  
Interior Space ◽  
Industry Foundation Classes ◽  
Geography Markup Language ◽  
Building Model ◽  
Building Models ◽  
Outdoor Scenes ◽  
Indoor Spaces ◽  
Indoor And Outdoor

The level of detail (LoD) concept in CityGML (City Geography Markup Language), which indicates how closely the model mirrors its real-world counterpart, has been accepted and applied widely in various applications, including the 3D modeling of buildings. However, with an increasing number of human activities occurring in the indoor environment, the standardized LoD definition appears to be insufficient because of its narrow classifications for interior features, which can be presented only in LoD4. In view of this drawback, an extended indoor LoD (ILoD) specification is proposed, particularly for indoor spaces, allowing the existing LoD to become a more precise outdoor LoD (OLoD) by exploiting the advantages of two other international standards: Industry foundation classes (IFC) and IndoorGML. In this paper, the interior space is divided into distinct systems of three semantic aspects (structure, connectivity, and volume); the approach can be considered the guiding ideology to define the detailed indoor levels following a concrete theoretical realization based on extending the UML diagram of CityGML’s building model. Moreover, a continuous and seamless full LoD (FLoD) set obtained by combining various OLoDs and ILoDs is subsequently listed to realize the full specification for 3D building models. Furthermore, to demonstrate the proposed specification and prove the applicability of the building model at different LoDs, a practical experiment is conducted.

Ontology Engineering Method for Integrating Building Models

2014 ◽  
pp. 151-185 ◽  
Author(s):  
Mohamed El-Mekawy ◽  
Anders Östman
Keyword(s):  
Spatial Information ◽  
Unified Model ◽  
Industry Foundation Classes ◽  
Geography Markup Language ◽  
Building Model ◽  
Building Models ◽  
Information Models ◽  
Semantic Models ◽  
Great Heterogeneity ◽  
Building Information

The Industry Foundation Classes (IFC) and City Geography Markup Language (CityGML) are the two most prominent semantic models for the representation of Building Information Models (BIM) and geospatial objects. IFC and CityGML use different terminologies to describe the same domain, and there is a great heterogeneity in their semantics. For bidirectional conversions between these models, an intermediate Unified Building Model (UBM) is proposed that facilitates the transfer of spatial information from IFC to CityGML and vice versa. A unified model in the current study is defined as a superset model that is extended to contain all the features and objects from both IFC and CityGML building models. The conversion is a two-steps process in which a model is first converted to the unified model and then to the target model.

scholarly journals Data transfer between digital models of built assets and their operation & maintenance systems

2020 ◽  
Vol 25 ◽  
pp. 469-481
Author(s):  
Kay Rogage ◽  
David Greenwood
Keyword(s):  
Data Transfer ◽  
Hybrid Approach ◽  
Facilities Management ◽  
Industry Foundation Classes ◽  
Building Model ◽  
Building Models ◽  
Information Models ◽  
Building Information ◽  
The Many ◽  
Transfer Of Information

The operation and maintenance of built assets is crucial for optimising their whole life cost and efficiency. Historically, however, there has been a general failure in the transfer information between the design-and-construct (D&C) and operate-and-maintain (O&M) phases of the asset lifecycle. The recent steady uptake of digital technologies, such as Building Information Modelling (BIM) in the D&C phase has been accompanied by an expectation that this would enable better transfer of information to those responsible for O&M. Progress has been slow, with practitioners being unsure as to how to incorporate BIM into their working practices. Three types of challenge are identified, related to communication, experience and technology. In examining the last aspect, it appears that a major problem has been that of interoperability between building information models and the many computer-aided facilities management (CAFM) systems in use. The successful and automatic transfer of information from a building model to an FM tool is, in theory, achievable through the medium of the Industry Foundation Classes (IFC) schema. However, this relies upon the authoring of the model in terms of how well its structure permits the identification of relevant objects, their relationships and attributes. The testing of over 100 anonymised building models revealed that very few did; prohibiting their straightforward mapping to the maintenance database we had selected for the test. An alternative, hybrid approach was developed using an open-source software toolkit to identify objects by their geometry as well as their classification, thus enabling their automatic transfer. In some cases, manual transfer proved necessary. The implications are that while these problems can be overcome on a case-by-case basis, interoperability between D&C and O&M systems will not become standard until it is accommodated by appropriate and informed authoring of building models.

scholarly journals Requirements, Development, and Evaluation of A National Building Standard—A Swedish Case Study

2020 ◽  
Vol 9 (2) ◽  
pp. 78 ◽  
Author(s):  
Helen Eriksson ◽  
Tim Johansson ◽  
Per-Ola Olsson ◽  
Maria Andersson ◽  
Jakob Engvall ◽  
...  
Keyword(s):  
Classification System ◽  
International Standards ◽  
Legal Information ◽  
Industry Foundation Classes ◽  
Building Model ◽  
Information Models ◽  
Building Information ◽  
Requirements Development ◽  
Index Maps

The aim of this paper is to present a proposal for a national building standard in Sweden. We define requirements for the proposed standard, e.g., it should support development of 3D city models, connect to building information models (BIM) and national registers and be based on a national classification system for the urban environment. Based on these requirements we develop an Application Domain Extension (ADE) of the building model in the proposed CityGML 3.0 standard denoted CityGML Sve-Test. CityGML 3.0 includes several new features of interest, e.g., the space concept, enhanced possibilities to convert data, and to link to other standards. In our study we create test data according to CityGML Sve-Test and evaluate it against the requirements. It is shown that BIM models (in Industry Foundation Classes, IFC, format) can be converted to CityGML Sve-Test and that a classification system facilitates this conversion. The CityGML Sve-Test dataset can be used to increase the automation level in building permissions checking and a related study shows that CityGML 3.0 has capabilities to link to legal information and be a base for 3D cadastral index maps. Based on our experience, we suggest that the national building standard should conform to international standards and, if possible, include a classification system. The exchange format (GML, JSON etc.) might change, but to be based on a standardized data model ensures harmonized structures and concepts.

scholarly journals Seismic Damage Semantics on Post-Earthquake LOD3 Building Models Generated by UAS

2021 ◽  
Vol 10 (5) ◽  
pp. 345
Author(s):  
Konstantinos Chaidas ◽  
George Tataris ◽  
Nikolaos Soulakellis
Keyword(s):  
Point Clouds ◽  
Recovery Phase ◽  
Seismic Damage ◽  
Unmanned Aircraft ◽  
Earthquake Scenario ◽  
Geography Markup Language ◽  
3D Point Clouds ◽  
Building Models ◽  
Building Walls ◽  
Oblique Images

In a post-earthquake scenario, the semantic enrichment of 3D building models with seismic damage is crucial from the perspective of disaster management. This paper aims to present the methodology and the results for the Level of Detail 3 (LOD3) building modelling (after an earthquake) with the enrichment of the semantics of the seismic damage based on the European Macroseismic Scale (EMS-98). The study area is the Vrisa traditional settlement on the island of Lesvos, Greece, which was affected by a devastating earthquake of Mw = 6.3 on 12 June 2017. The applied methodology consists of the following steps: (a) unmanned aircraft systems (UAS) nadir and oblique images are acquired and photogrammetrically processed for 3D point cloud generation, (b) 3D building models are created based on 3D point clouds and (c) 3D building models are transformed into a LOD3 City Geography Markup Language (CityGML) standard with enriched semantics of the related seismic damage of every part of the building (walls, roof, etc.). The results show that in following this methodology, CityGML LOD3 models can be generated and enriched with buildings’ seismic damage. These models can assist in the decision-making process during the recovery phase of a settlement as well as be the basis for its monitoring over time. Finally, these models can contribute to the estimation of the reconstruction cost of the buildings.

scholarly journals Towards Effective BIM/GIS Data Integration for Smart City by Integrating Computer Graphics Technique

2021 ◽  
Vol 13 (10) ◽  
pp. 1889
Author(s):  
Junxiang Zhu ◽  
Peng Wu
Keyword(s):  
Computer Graphics ◽  
Smart City ◽  
Smart Cities ◽  
Information Modeling ◽  
Data Conversion ◽  
Geography Markup Language ◽  
Building Models ◽  
Digital Twins ◽  
Gis Data ◽  
Building Information

The development of a smart city and digital twin requires the integration of Building Information Modeling (BIM) and Geographic Information Systems (GIS), where BIM models are to be integrated into GIS for visualization and/or analysis. However, the intrinsic differences between BIM and GIS have led to enormous problems in BIM-to-GIS data conversion, and the use of City Geography Markup Language (CityGML) has further escalated this issue. This study aims to facilitate the use of BIM models in GIS by proposing using the shapefile format, and a creative approach for converting Industry Foundation Classes (IFC) to shapefile was developed by integrating a computer graphics technique. Thirteen building models were used to validate the proposed method. The result shows that: (1) the IFC-to-shapefile conversion is easier and more flexible to realize than the IFC-to-CityGML conversion, and (2) the computer graphics technique can improve the efficiency and reliability of BIM-to-GIS data conversion. This study can facilitate the use of BIM information in GIS and benefit studies working on digital twins and smart cities where building models are to be processed and integrated in GIS, or any other studies that need to manipulate IFC geometry in depth.

scholarly journals A Common Approach to Geo-Referencing Building Models in Industry Foundation Classes for BIM/GIS Integration

2021 ◽  
Vol 10 (6) ◽  
pp. 362
Author(s):  
Junxiang Zhu ◽  
Peng Wu
Keyword(s):  
Building Information Modeling ◽  
Information Modeling ◽  
Industry Foundation Classes ◽  
Spatial Reference ◽  
Reference Information ◽  
Building Models ◽  
Digital Twins ◽  
Gis Data ◽  
Gis Integration ◽  
Building Information

Previous geo-referencing approaches for building information modeling (BIM) models can be problematic due to: (a) the different interpretations of the term ‘geo-referencing’, (b) the insufficient consideration of the placement hierarchy of the industry foundation classes (IFCs), and (c) the misunderstanding that a common way to embed spatial reference information for IFC is absent. Therefore, the objective of this study is to (1) clarify the meaning of geo-referencing in the context of BIM/GIS data integration, and (2) develop a common geo-referencing approach for IFC. To achieve the goal, a systematic and thorough investigation into the IFC standard was conducted to assess the geo-referencing capability of IFC. Based on the investigation, a geo-referencing approach was established using IFC entities that are common in different IFC versions, which makes the proposed approach common to IFC. Such a geo-referencing approach supports automatic geo-referencing that would facilitate the use of BIM models in GIS, e.g., for the construction of digital twins.

Building pose estimation from the perspective of UAVs based on CNNs

2021 ◽  
pp. 2150003
Author(s):  
Zhenni Wu ◽  
Hengxin Chen ◽  
Bin Fang ◽  
Zihao Li ◽  
Xinrun Chen
Keyword(s):  
Neural Network ◽  
Pose Estimation ◽  
Computer Technology ◽  
Architectural Design ◽  
Rapid Development ◽  
Angle Error ◽  
Building Model ◽  
Building Models ◽  
World Coordinate System ◽  
Aerial Vehicle

With the rapid development of computer technology, building pose estimation combined with Augmented Reality (AR) can play a crucial role in the field of urban planning and architectural design. For example, a virtual building model can be placed into a realistic scenario acquired by a Unmanned Aerial Vehicle (UAV) to visually observe whether the building can integrate well with its surroundings, thus optimizing the design of the building. In the work, we contribute a building dataset for pose estimation named BD3D. To obtain accurate building pose, we use a physical camera which can simulate realistic cameras in Unity3D to simulate UAVs perspective and use virtual building models as objects. We propose a novel neural network that combines MultiBin module with PoseNet architecture to estimate the building pose. Sometimes, the building is symmetry and ambiguity causes its different surfaces to have similar features, making it difficult for CNNs to learn the differential features between the different surfaces. We propose a generalized world coordinate system repositioning strategy to deal with it. We evaluate our network with the strategy on BD3D, and the angle error is reduced to [Formula: see text] from [Formula: see text]. Code and dataset have been made available at: https://github.com/JellyFive/Building-pose-estimation-from-the-perspective-of-UAVs-based-on-CNNs .

Novel Scenes Improve Recollection and Recall of Words

2008 ◽  
Vol 20 (7) ◽  
pp. 1250-1265 ◽  
Author(s):  
Daniela B. Fenker ◽  
Julietta U. Frey ◽  
Hartmut Schuetze ◽  
Dorothee Heipertz ◽  
Hans-Jochen Heinze ◽  
...  
Keyword(s):  
Specific Activity ◽  
Activity Patterns ◽  
Long Term Potentiation ◽  
Contextual Memory ◽  
Memory Enhancement ◽  
Term Potentiation ◽  
Outdoor Scenes ◽  
Indoor And Outdoor ◽  
Hippocampus Dependent Memory

Exploring a novel environment can facilitate subsequent hippocampal long-term potentiation in animals. We report a related behavioral enhancement in humans. In two separate experiments, recollection and free recall, both measures of hippocampus-dependent memory formation, were enhanced for words studied after a 5-min exposure to unrelated novel as opposed to familiar images depicting indoor and outdoor scenes. With functional magnetic resonance imaging, the enhancement was predicted by specific activity patterns observed during novelty exposure in parahippocampal and dorsal prefrontal cortices, regions which are known to be linked to attentional orienting to novel stimuli and perceptual processing of scenes. Novelty was also associated with activation of the substantia nigra/ventral tegmental area of the midbrain and the hippocampus, but these activations did not correlate with contextual memory enhancement. These findings indicate remarkable parallels between contextual memory enhancement in humans and existing evidence regarding contextually enhanced hippocampal plasticity in animals. They provide specific behavioral clues to enhancing hippocampus-dependent memory in humans.

scholarly journals POST-EARTHQUAKE 3D BUILDING MODEL (LOD2) GENERATION FROM UAS IMAGERY: THE CASE OF VRISA TRADITIONAL SETTLEMENT, LESVOS, GREECE

2020 ◽  
Vol XLIV-4/W3-2020 ◽  
pp. 165-172
Author(s):  
K. Chaidas ◽  
G. Tataris ◽  
N. Soulakellis
Keyword(s):  
Laser Scanner ◽  
Building Model ◽  
Levels Of Detail ◽  
Building Models ◽  
Digital Elevation ◽  
3D Building Model ◽  
Modelling Techniques ◽  
Camera Position ◽  
Elevation Model ◽  
Comparison Of The Results

Abstract. In recent years 3D building modelling techniques are commonly used in various domains such as navigation, urban planning and disaster management, mostly confined to visualization purposes. The 3D building models are produced at various Levels of Detail (LOD) in the CityGML standard, that not only visualize complex urban environment but also allows queries and analysis. The aim of this paper is to present the methodology and the results of the comparison among two scenarios of LOD2 building models, which have been generated by the derivate UAS data acquired from two flight campaigns in different altitudes. The study was applied in Vrisa traditional settlement, Lesvos island, Greece, which was affected by a devastating earthquake of Mw = 6.3 on 12th June 2017. Specifically, the two scenarios were created by the results that were derived from two different flight campaigns which were: i) on 12th January 2020 with a flying altitude of 100 m and ii) on 4th February 2020 with a flying altitude of 40 m, both with a nadir camera position. The LOD2 buildings were generated in a part of Vrisa settlement consisted of 80 buildings using the footprints of the buildings, Digital Surface Models (DSMs), a Digital Elevation Model (DEM) and orthophoto maps of the area. Afterwards, a comparison was implemented between the LOD2 buildings of the two different scenarios, with their volumes and their heights. Subsequently, the heights of the LOD2 buildings were compared with the heights of the respective terrestrial laser scanner (TLS) models. Additionally, the roofs of the LOD2 buildings were evaluated through visual inspections. The results showed that the 65 of 80 LOD2 buildings were generated accurately in terms of their heights and roof types for the first scenario and 64 for the second respectively. Finally, the comparison of the results proved that the generation of post-earthquake LOD2 buildings can be achieved with the appropriate UAS data acquired at a flying altitude of 100 m and they are not affected significantly by a lower one altitude.

scholarly journals A Semantics-Based Approach for Simplifying IFC Building Models to Facilitate the Use of BIM Models in GIS

2021 ◽  
Vol 13 (22) ◽  
pp. 4727
Author(s):  
Junxiang Zhu ◽  
Peng Wu ◽  
Chimay Anumba
Keyword(s):  
Information Modeling ◽  
Markup Language ◽  
Model Simplification ◽  
Geography Markup Language ◽  
Building Models ◽  
Solid Models ◽  
External Objects ◽  
Surface Models ◽  
Level Of Details ◽  
Building Information

Using solid building models, instead of the surface models in City Geography Markup Language (CityGML), can facilitate data integration between Building Information Modeling (BIM) and Geographic Information System (GIS). The use of solid models, however, introduces a problem of model simplification on the GIS side. The aim of this study is to solve this problem by developing a framework for generating simplified solid building models from BIM. In this framework, a set of Level of Details (LoDs) were first defined to suit solid building models—referred to as s-LoD, ranging from s-LoD1 to s-LoD4—and three unique problems in implementing s-LoDs were identified and solved by using a semantics-based approach, including identifying external objects for s-LoD2 and s-LoD3, distinguishing various slabs, and generating valid external walls for s-LoD2 and s-LoD3. The feasibility of the framework was validated by using BIM models, and the result shows that using semantics from BIM can make it easier to convert and simplify building models, which in turn makes BIM information more practical in GIS.

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