Another question related to the georeferencing. One that also Hans Lammerts has commented about on another forum.
How is the height level defined?
I tried a model that has a correct X/Y implantation using Lambert72 (EPSG: 31370). It shows on the correct location with the Cesium tiles.
However for the height there is a difference of about 1.5m. I don’t know the exact level of the current terrain, but I know that our foundation is supposed to be +/- flush with the current terrain. And that difference I figured out with some box geometry to be +/- 1500mm.
Hans commented that it could likely be that the 3D tiles are using WGS84. It looks like for the X/Y transformation something is in place to transform from another CRS (like Lambert) to the WGS84. But since those CRS have no information about height I assume that is the reason no transformation is made?