How to get a xyz-Vectorlayer (eg. for surface) into Cesium with 3DTiles?

I have a xyz-Vectorlayer in qgis which I want to display as a surface layer in Cesium. My current proposal is:
1) save as polygon shape in QGIS with position and height in its geometry,
2) import via BlenderGIS into Blender
3) export as glb with gltf-blender exporter,
4) convert to b3dm with the 3d-tiles-tools.

Unfortunately, in Blender a lot of faces are shown as "flipped", which can be turn around, but only with enormous expenditure of time. As a result, my surface layer in Cesium has holes in it.

My question:
Is there a more elegant way to get the surface layer from QGIS into Cesium 3DTiles?

Additionally i tests Blender options for Meshes: "Double Sided" and in the Export to deactivate "Export normals" - there are still holes in my surface layer in Cesium (in Blender they disappeared)

Converted the shapefile following this way now. But made a duplicate of the mesh in Blender to cover the backfaces on each side.

Cesium ion doesn’t currently tile vector data but it’s definitely something we’d like to support in the future. If you can export it out of QGIS as an OBJ you can try to upload it to ion ( and it’ll tile it up. Although if the faces aren’t facing the right way it might still be an issue. This reminds me that having a double sided geometry option in ion would be pretty useful in this case. I believe this is something we plan to support but no specific timeline on it yet.