Yichuan Deng

A framework for 3D traffic noise mapping using data from BIM and GIS integration

Abstract Traffic noise is a major health concern for people living in urban environments. Noise mapping can help evaluating the noise level for certain areas in a city. Traditionally, noise mapping is performed in 2D geographic information system (GIS). The use of 3D GIS is also emerging in noise mapping in recent years. However, the current noise-mapping platforms can only conduct noise evaluation for the outdoor environment and the indoor environment separately. In addition, related information about absorption coefficient and transmission loss (TL) in noise calculation is not properly retrieved and is often replaced with a single value. In this research, building information modelling (BIM) and 3D GIS are integrated in order to combine traffic noise evaluation in both outdoor environments and indoor environments in a single platform. In our developed BIM–GIS integration platform, the built environment is represented in a 3D GIS model that contains information at a high level of detail from BIM. With the integration with BIM, the 3D GIS model now has access to detailed indoor features such as interior walls and interior rooms. Noise evaluation could therefore be performed at a room level in the developed platform. Essential parameters such as absorption coefficient and TL can be extracted directly from BIM for noise calculation. The 3D GIS model is connected with detailed BIM so that any changes in the indoor and outdoor features can be reflected to each other. The Italian C.N.R model is modified and applied in the platform to conduct noise calculation. This paper presents the details for the development of the noise-mapping BIM–GIS platform based on ArcGIS. Two use cases were analysed to show the role of such platform in the decision-making process of both urban planning and interior design.

Automatic Transformation of Different Levels of Detail in 3D GIS City Models in CityGML

3D Geographic Information System GIS models are increasingly used for planning and analyses on a city level. Defining 3D GIS city models in different levels of detail LoD is often needed to browse and handle large models more efficiently. In this paper, a methodology framework for automatic transformation of different LoDs in CityGML is presented and illustrated. A new exterior shell extraction algorithm was developed from the Ray Tracing algorithm for classifying building surfaces as interior or exterior. A transformation framework among each LoD was developed based on the new exterior shell extraction algorithm. The transformation framework also includes an additional LoD called LoD3.5 that the authors proposed in this paper. The new LoD can satisfy the needs of applications which require information about interior rooms while maintaining a small data storage. The results show that the new exterior shell extraction algorithm can help achieve an automatic derivation of LoDs in CityGML.

An Integrated BIM-GIS Framework for Utility Information Management and Analyses

Currently, utility information such as alignment and owner information is mostly managed in 2D CAD files or 2D geographical information system (GIS) models, which have limited capacity for analyses and are sometimes not updated. This paper presents an integrated 3D framework based on building information modeling (BIM) and GIS technologies for managing and analyzing utility information. In the framework, underground utility networks are modeled and represented in GIS software to facilitate visualization. Semantic information such as owner information and inspection records are also included in the 3D representations of utilities in GIS software. The GIS models are then integrated in a BIM environment based on ArcGIS using our developed BIM-GIS integration framework. The BIM-GIS framework supports various analyses such as clash detection. Clashes between existing utility networks and the designed pipelines can be identified and resolved virtually ahead of time. Changes of the utility models can also be updated conveniently in the integrated BIM-GIS framework. An example scenario that is used to test and evaluate the developed framework will be presented in this paper.

Evaluation of IFC4 for the GIS and Green Building Domains

In the BIM domain, Industry Foundation Classes (IFC) is the major data exchange standard. In March 2013, IFC4 was released as the new IFC standard. IFC4 has many changes in scope, entities, and data representations. In particular, IFC4 has been enriched to support geographical information and green building design. In IFC4, a building design can be linked to a GIS coordinate system and vice versa. There are also improvements in IFC4 for energy analysis, building service systems, and lighting and shading components. In this paper, changes in IFC4 in the aspects of GIS and green buildings were identified and evaluated using the versioning technique and domain knowledge. CityGML and gbXML were selected as the representative data schemas in the GIS domain and the green building domain, respectively. The version differences were compared with the domain knowledge using linguistic-based method to discover the mapping between IFC4 and CityGML/gbXML. The missing elements in IFC4 for the two domains were also identified for further investigation.