2026-07-09 –, Bakker-Nortzaal Language: English
National-scale 3D city model datasets are expanding rapidly -- Japan's PLATEAU project alone publishes over 170,000 files, and the Netherlands' 3DBAG covers all approximately 11 million buildings in the country -- yet no standardised mechanism exists for discovering and cataloguing these datasets across repositories.
Essential properties such as coordinate reference systems, levels of detail (LoDs), and types of city objects remain embedded inside data files in a variety of formats (for example, CityGML, CityJSON, or FlatCityBuf), making them invisible to search engines and catalogue services.
We will present and discuss three contributions we have made to address that gap:
- The STAC 3D City Models Extension, a formal extension to the SpatioTemporal Asset Catalog (STAC) specification that adds metadata fields for LoDs, city object types, semantic surfaces, textures, materials, and attribute schemas.
- The software
city3dstac, an open-source command-line tool written in Rust that automatically extracts metadata from 3D city models in multiple formats and generates STAC-compliant metadata. <> - A prototype registry that currently indexes several STAC Collections around the world. It already includes the national-scale 3D BAG, American Cities, and Estonia datasets, PLATEAU, and more are being added.
Existing STAC clients can browse the catalogue without modification, demonstrating that 3D city model metadata integrates directly into the broader geospatial data infrastructure.
This is work-in-progress from my research lab and I think it's interesting for the NL community.
Hugo Ledoux is an associate-professor in 3D geoinformation at the Delft University of Technology in the Netherlands. He holds a PhD in computer science from the University of South Wales (UK) and a BSc in geomatics engineering from the Université Laval (Québec City, Canada). For his research, he is particularly interested in combining the fields of GIS and computational geometry. He is currently working on the efficient storage of 3D city models with CityJSON, the reconstruction of massive TINs, the validation and the automatic repair of polygons and polyhedra as found in GIS, and the semantic classification of urban textured meshes. He is also the programme director of the MSc Geomatics at TUDelft.
A PhD candidates of TU Delft