Modelling and managing massive 3D data of the built environment

A 3D city model is a digital representation of the spatial features in an urban<br/>environment. Buildings, terrain, vegetation, water bodies, etc. all form an integral part of a 3D city model. The possibility to enrich these city models with additional application-specific information, whether new semantics or geometry, further increases their...

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...

An Improved LOD Framework for the Terrains in 3D City Models

The Level of Detail (LOD) concept in CityGML 2.0 is meant to differentiate the multiple representations of semantic 3D city models. Despite the popularity and general acceptance of the concept by the practitioners and stakeholders in 3D city modelling, there are still some limitations. While the CityGML LOD concept is well defined for buildings,...

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...

A metadata ADE for CityGML

While there exist international standards for geospatial metadata (ISO 19115), these are rarely used in practice for 3D datasets, and one of the OGC standards for 3D city models, CityGML, does not offer a mechanism to store metadata in a structured way. Having metadata in CityGML files, which are in practice often very large and complex, would...

CityGML Application Domain Extension (ADE): overview of developments

The Application Domain Extension (ADE) is a built-in mechanism of CityGML to augment its data model with additional concepts required by particular use cases. The goal of this paper is to provide an overview of the ADE mechanism and a literature review of developments since its introduction a decade ago. The discovery of publications found that...