Hi @kientegadesire4​,

There is no need to set the output coordinate system for Cesium, since the 3D Tiles format allows only a Geocentric (ECEF) coordinate system, and that is what all output data will be reprojected to.

The problem is likely due to the source Revit coordinate system. Some Revit files include coordinate system information, and FME will apply this if the parameter Revit Coordinate System to Read is set to Georeferenced. However, most Revit files currently do not include the coordinate system info, so it is necessary to determine the world location of the file's origin and use that in the LocalCoordinateSystemSetter to create a local coordinate system. This location can be in lat/long, State Plane, or any of the other coordinate systems supported by FME.

I tried with other revit files and i didn't set output coordinate! but i still have the same issue!

Do you have any exemples that is working? or any rvt file that's work