How to upload georeferenced models

I have point clouds and textured meshes generated from the same photogrammetry survey. They are co-registered in the same CRS (EPSG:25833). When I embed the EPSG:25833 into the las files and upload the point clouds to Cesium ion, they are automatically georeferenced. But I cannot achieve the same with the meshes (I tried .fbx and .obj with a .proj file). Since my models are accurately georeferenced, I don’t think it makes sense if I have to manually set the tileset location. Does anyone have any experience with this issue?

Thank you in advance!

right now what i am doing is:

  1. find the surface centroid (x, y, h) of the .obj model and apply a translation to make the centroid move to (0, 0, 0)
  2. using python to convert the original surface centroid coordinate (x, y, h) from EPSG 25833 to EPSG 4979, which results in (lon, lat, h)
  3. upload the translated model to Cesium ion and then input the longitude, latitude, and height i got from step 2, adjust the height manually if needed
  4. set the rotation heading to -0.97

In this way, I can get my .obj model georeferenced somewhat accurately, but it is not straight-forward. I would like to know if you have any better ideas!