I am currently trying to add a gml:id attribute to all my CityGML geometries in FME. I can easily create this attribute for each object (i.e. PlantCover, Road, RoofSurface ...). However, when I want to assciate a material to a surface, I need to grab the id of the surface (i.e the geometry gml:Polygon). How can I do that in FME ?
Best regards,
Asher