CityJSON

FlatCityBuf: A new cloud-optimised CityJSON 🚀

Thu, 17 Jul 2025 00:00:00 +0000

We are softly releasing FlatCityBuf, see its webpage. It’s still in beta, but it is usable and shows its potential.

Hidemichi Baba will be presenting FlatCityBuf at the next 3DGeoInfo conference in Tokyo also! We hope to see you there!

CityJSONSeq now has its own media type

Thu, 31 Oct 2024 10:05:00 +0000

CityJSONSeq now has its own media type, which is also known as a MIME type (Multipurpose Internet Mail Extensions).

A media type indicates the content and format of a document, and is widely used on the web.

CityJSONSeq has the following type: application/city+json-seq.

CityJSON files also have their own media type: application/city+json.

Large datasets? CityJSONSeq!

Mon, 16 Sep 2024 00:00:00 +0000

If you have to deal with very large datasets, we recommend you have a look at our solution CityJSONSeq.

We also have a scientific paper and the presentation of it.

CityJSON v2.0 now also an OGC community standard

Mon, 06 Nov 2023 09:40:00 +0000

We’re happy to announce that the latest version of CityJSON is now officially an OGC standard!

Thanks to all who supported Geonovum, 3DGI, and us in the process 🙏

CityJSON Community Standard (document 20-072r5)

CityJSON v2.0 is released 🚀

Wed, 27 Sep 2023 15:59:00 +0000

We’ve been working hard, in collaboration with Geonovum, on improving CityJSON and we’re happy today to release version 2.0 🎉🍾🚀

The full specifications

CityJSON v2.0.0 specifications

Software

Perhaps more importantly, we have updated the eco-systems:

cjio has been updated to v0.9 and offers an upgrade operator to automatically upgrade your existing files to v2.0
cjval (the official validator)
you can upgrade your files automatically and pain-free
the online view ninja supports v2.0 already

Other software like azul, FME, and citygml4j will be updated soon.

Developer?

If you are a developer, you can see on this page what you need to do to update your code to be ready for v1.1 files. Most changes are small, and we expect this upgrade to take a maximum of a few minutes.

Hello Revit

Fri, 03 Mar 2023 11:30:00 +0000

The 3D geoinformation group at TU Delft is glad to announce the release of CityJSON importer, a new plugin available for Autodesk® Revit®.

This plugin uses coordination referencing system (CRS) and metadata to reproject and translate the data, ensuring seamless implementation within Revit.

The plugin can be downloaded free of charge at the Autodesk App Store, and its source code is openly available for users who wish to access it.

CityJSON v1.1.3 released

Fri, 25 Nov 2022 13:33:00 +0000

Patch release where the schemas are essentially the same, and where the text of the specs is better/sharper.

Changed

CityJSONFeatures now do not have to dereference the GeometryTemplates, those can be in the “1st line”/metadata. Dereferencing is still allowed. cjio passes the GeometryTemplates in the 1st-line now.
CityJSONFeature: now clear that all children (recursively) of a feature should be bundled with its parent.
improved the text of the specifications at several places, and fixed sentences that were not precise enough.
change the "uri" to "url" for the Extensions, and now the schemas can have either of these. Going forward "url" is the preferred way.
restructured the text for the Extensions, now a 4th use-case is added: “Defining a new Semantic Object”. It was always there but not listed as a case. Now fixed.

Added

"BuildingConstructiveElement" was missing from the schemas as a CO, now added.
added 2 suggested conventions in the specs: file extensions .city.json and .city.jsonl

For those who want to know precisely what words changed, check the diff.

{🌳🏢🏠}

Hello Rhino

Thu, 03 Nov 2022 16:22:00 +0000

We’re happy to announce that Rhino 3D now has CityJSON support via Grasshopper. The GH plugin consists out off a small set of components that can expose and bake the stored data. The format in which the data is exposed enables easy integration with both native GH components and other powerful plugins, for example Ladybug.

The pre-build plugin can be found on Food4Rhino, and the code is open-source.

CityJSON v1.1.2 released

Tue, 16 Aug 2022 11:32:00 +0000

Minor changes to the schemas for errors, improved the text of the specs so that it’s easier for everyone to read and understand.

What changed:

fixed the typo in the schema: "TunnelFurniture"
added the missing CityGML v3 types in the schemas: "BridgeFurniture" and "Waterway" and "BuildingConstructiveElement"
added a link in the specs text to the official CityGML v3 specs for definitions of each of the City Objects
improved and added a few sentences in the specs to make them clearer
small improvements in the specs document to make concepts clearer
schemas are the same, with some simplifications to make their maintenance easier in the future

For those who want to know precisely what words changed, check the diff.

{🌳🏢🏠}

Our viewer ninja has improved a lot!

Fri, 01 Jul 2022 08:29:00 +0000

The official web-viewer for CityJSON files has been improving a lot recently.

If you haven’t used it in a while, you’ll be surprised, you can now:

see selected semantic surface information in the information panel
highlight only the selected surface
select which LoD to display if your file has more than one (this was often requested)
better see your Extension objects
and several small improvements!