Hello @bayram, thanks for posting! I had a look at your data & workspace. I was able to produce a valid CityGML file, but unfortunately no geometry is being written to the file, which is why we aren't seeing an output in the FZK Viewer. In order to write geometry, we need to populate or write to specific CityGML geometry related format attributes and properties. Most of these properties & values can be found in our documentation, like LOD name (eg. citygml_lod_name) and citygml role for example. This documentation page will also show you a short list of acceptable geometries for each feature type.

Thankfully there is a custom transformer on the FME Hub that will create these attributes for us: CityGMLGeometrySetter.

If you aren't overly familiar with CityGML or GML writing, I might suggest you review a resource that demonstrates how to write CityGML datasets:

BIM to GIS (Basic) | IFC LOD 100 to LOD 2 CityGML (Step 4)
BIM to GIS (Advanced) | IFC LOD 200 to LOD 3 CityGML (Step 14)

I've identified the step in each article that sets the CityGML geometry properties. Hopefully these resources will share concepts that you can apply to your own data. Note, it might be easiest to start off writing 1 or 2 feature types, before trying to write the entire file.

If after reviewing the tutorials and documentation you are still unable to produce geometry, please reach out with an update. Will be happy to look at the workflow with you. Happy to help, Kailin.

thank you very much for your answer