Exporting Blender models to CityJSON

Introduction

It is possible to import CityGML file into the Tygron Platform. This article deals with exporting a Blender model to CityJSON so that it can be imported into the Tygron Platform via the CityGML importer.

(Blender is the free and open source 3D creation suite. To learn more about blender visit https://www.blender.org/ or https://en.wikipedia.org/wiki/Blender_(software))

In order to export Blender models to CityJSON we first need to install the Up3date exporter and install it as an add-on in to Blender. This add-on was originally developed by Konstantinos Mastorakis (konmast3r) as part of their research orientation project for the MSc Geomatics programme of TU Delft. Its functionality was further developed for the needs of their MSc thesis An integrative workflow for 3D city model versioning.

Setting up the exporter in Blender.

1. Visit https://github.com/cityjson/Up3date and download the zip file from the green Code dropdown menu on the right side.
2. Open Blender and go to Edit -> Preferences.
3. In the preference dialog click on "Add-ons". You can see a list of the add-ons which are available for Blender.
4. Click on "Install" in the top right and select the zip file which you have downloaded. 5. After install the exporter will be available in the list. (Import-Export: Import CityGML) 6. Click on the checkbox next to it to activate the exporter. 7. Close the Preferences dialog.