The GEORES SketchUp CityGML Plugin allows to import and export CityGML files. It also provides functionalities to annotate meshes and faces with the according CityGML classes and attributes.
The code has originally been developed by Wolfgang Sach and distributed by his company GEORES. In 2018, Wolfgang stopped development on the project and released the code as open source. Since 2019, the GEORES Plugin is free to use and released under the MIT license.
Pull requests welcome!
Download the geores.rbz from here and use
SketchUp Extension Manager to install.