Applying versioning to multi-LoD 3D city models

Level of Detail (LoD) is a well known concept in 3D city models, used to designate different geometric detail that can be used in different applications. Nevertheless, multi-LoD datasets are hard to maintain and manage because of their intrinsic complexity. Versioning is a solution that aids in the storage and management of big and complex...

Development and Testing of the CityJSON Energy Extension for Space heating Demand Calculation

3D city models are frequently used to acquire and store energy-related information of buildings for energy applications. In this context, CityGML is the most common data model, and the Energy ADE, one of its most complex extensions, provides a systematic way of storing detailed energy-related data in XML format. Contrarily, even though...

Automatic conversion of CityGML to IFC

The trend of increased usage of both BIM and 3D GIS and the similarity between the two has led to an increase in the overlap between them. A key application of such overlap is providing geospatial context data for BIM models through importing 3D GIS-data to BIM software to help in different design-related issues. However, this is currently...

Tools for BIM-GIS Integration (IFC Georeferencing and Conversions): Results from the GeoBIM Benchmark 2019

The integration of 3D city models with Building Information Models (BIM), coined as GeoBIM, facilitates improved data support to several applications, e.g., 3D map updates, building permits issuing, detailed city analysis, infrastructure design, context-based building design, to name a few. To solve the integration, several issues need to be...

THE ISPRS-EUROSDR GEOBIM BENCHMARK 2019

Standardised data formats and data models are essential for data integration and interoperability, which in turn adds value to data by allowing its reuse in multiple contexts. For this reason, in recent years extensive efforts have been focused on standards development. When representing the built environment, 3D city models and Building...

Reference study of CityGML software support: The GeoBIM benchmark 2019—Part II

OGC CityGML is an open standard for 3D city models intended to foster interoperability and support various applications. However, through our practical experience and discussions with practitioners, we have noticed several problems related to the implementation of the standard and the use of standardized data. Nevertheless, a systematic...

CityJSON: a compact and easy-to-use encoding of the CityGML data model

The international standard CityGML is both a data model and an exchange format to store digital 3D models of cities. While the data model is used by several cities, companies, and governments, in this paper we argue that its XML-based exchange format has several drawbacks. These drawbacks mean that it is difficult for developers to implement...

Incorporating topological representation in 3D City Models

3D city models are being extensively used in applications such as evacuation scenarios and energy consumption estimation. The main standard for 3D city models is the CityGML data model which can be encoded through the CityJSON data format. CityGML and CityJSON use polygonal modelling in order to represent geometries. True topological data...

The LandInfra standard and its role in solving the BIM-GIS quagmire

LandInfra is a relatively new open standard for modelling and representing land and infrastructure features. As it overlaps with other open standards in BIM (IFC) and 3D GIS (CityGML), it has been recognised as a potential candidate to bridge the gap between the two domains. However, the knowledge of this standard in both communities is low, and...

A Data Structure to Incorporate Versioning in 3D City Models

A 3D city model should be constantly updated with new versions, either to reflect the changes in its real-world counterpart, or to improve and correct parts of the model. However, the current standards for 3D city models do not support versioning, and existing version control systems do not work well with 3D city models. In this paper, we...

Harmonising the OGC Standards for the Built Environment: A CityGML Extension for LandInfra

The relatively new Open Geospatial Consortium (OGC) standard LandInfra documents in its data model land and civil engineering infrastructure features. It has a Geography Markup Language (GML) implementation, OGC InfraGML, which has essentially no software support and is rarely used in practice. In order to share the benefits of LandInfra (and...

GeoBIM benchmark 2019: Design and initial results

GeoBIM, the integration of 3D geoinformation (Geo) with building information models (BIM), is a subject of increasing attention in both domains. A well-known practical challenge for this integration is the mixed state of software support for open standards in each domain that would ease the integration. This is often known by practitioners but...

GeoBIM Benchmark 2019: Intermediate Results

An investigation into the implementation state of open standards in software is currently ongoing through the ISPRS/EuroSDR ‘GeoBIM benchmark 2019’ initiative, which kicked off earlier this year. The benchmark activity provides a way of assessing and comparing the functionality of different software packages in GIS and BIM in terms of their...