Assessment of the LoD Specification for the Integration of BIM-Derived Building Models in 3D City Models

Although level of detail (LoD) is a central concept in 3D city modelling, specifying different LoDs in an unambiguous manner is not straightforward. To resolve this, a set of frameworks have been developed. This paper evaluates the suitability of the LoD framework of (Biljecki et al. 2016) for 3D building models that have been generated directly...

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...

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...

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...

Modeling Cities and Landscapes in 3D with CityGML

CityGML is the most important international standard used to model cities and landscapes in 3D with extensive semantics. Compared to BIM standards such as IFC, CityGML models are usually less detailed but they cover a much greater spatial extent. They are also available in any of five standardized levels of detail. CityGML serves as an exchange...

Towards an integration of GIS and BIM data: What are the geometric and topological issues?

Geographic information and building information modelling both model buildings and infrastructure, but the way in which they are modelled is usually complimentary and BIM-GIS integration is widely considered as a way forward for both domains. For one, more detailed BIM data can feed more general GIS data and GIS data can provide the context...

Population Estimation Using a 3D City Model: A Multi-Scale Country-Wide Study in the Netherlands

The remote estimation of a region’s population has for decades been a key application of geographic information science in demography. Most studies have used 2D data (maps, satellite imagery) to estimate population avoiding field surveys and questionnaires. As the availability of semantic 3D city models is constantly increasing, we investigate...

Automatic Semantic-preserving Conversion Between OBJ and CityGML

We investigate the automatic conversion between two substantially different formats used in 3D city models: the ubiquitous but semantically poor Wavefront OBJ and the semantically rich but less used OGC standard CityGML. We elaborate on their differences and on the challenges involved in their conversion, such as the inference of semantics in an...

Modeling a 3D City Model and Its Levels of Detail as a True 4D Model

The various levels of detail (LODs) of a 3D city model are often stored independently, without links between the representations of the same object, causing inconsistencies, as well as update and maintenance problems. One solution to this problem is to model the LOD as an extra geometric dimension perpendicular to the three spatial ones,...

Automatically enhancing CityGML LOD2 models with a corresponding indoor geometry

Manipulating higher dimensional spatial information

Real-world phenomena have traditionally been modelled in a GIS in two and three dimensions. However, powerful insights can be gained by the integration of additional non-spatial dimensions, such as time and scale, in a higher dimensional spatial model. While this theory is conceptually sound, there is a lack of understanding of its consequences...