val3dity: validation of 3D GIS primitives according to the international standards

The validity of 3D primitives in 3D GIS datasets is often a prerequisite for using them in simulation and decision-making software, e.g. visibility analysis, noise pollution assessment, and energy estimation. However, while agreed definitions exist (in the international standard ISO19107), most software vendors ignore them and implement simpler 3D primitives, for instance by excluding interior boundaries in surfaces and/or solid. Such limitations prevent practitioners from exchanging and converting datasets, and thus to use these in other software and applications. I present in this paper val3dity, an open-source software to validate 3D primitives according to the international definitions of ISO19107. Practitioners can use it directly, without limitations: its code is freely available under the GPLv3 license, both binaries and a web-application are publicly available. It takes as input several formats (including the international standard CityGML), and outputs a report that helps users identify and understand the errors. I describe some of the engineering decisions supporting val3dity, and show that it can be used to validate real-world datasets.