Convert Geotif to Cesium and use it in Unreal (in local)


I have tried converting a Geotif file to read it in Unreal with Cesium.

I installed:

I launched the commands:
docker run -it --name ctb -v “d: / DockerFolder / terrain”: “/ data” tumgis / ctb-quantized-mesh

I used a geotif found at this address:

I launched the commands:
ctb-tile -f Mesh -C -N -o myOutput jotunheimen.tif
ctb-tile -f Mesh -C -N -l -o myOutput jotunheimen.tif

Files are generated (.terrain of 1 to 2 KB) but when I try to display it in Unreal with the following URL, nothing is displayed (In CesiumGeoreference, I went to the coordinates given by googleMap for this place):
file: /// D: /DockerFolder/terrain/myOutput/layer.json

I tried with other Geotiff, same result.
(Note: I don’t have a raster)

Did I miss something?

In one of your tutorial (Adding Datasets – Cesium), i can read this:

Currently, loading local quantized-mesh terrain files using Cesium for Unreal is not supported. However, terrain assets can be loaded from any server, including localhost . To load terrain assets completely offline, consider setting up a localhost to serve the terrain. The Url field can be filled using the same steps as above with http://localhost:portNumber/terrainAsset .

Does it means that i cannot load a terrain in a local folder of my PC in Unreal ? Or does it means that i can do that but using a server ?

When i try to use a server with my terrain (created using Cesium Terrain Builder Docker) i have this error:

LogCesium: Warning: [2021-09-24 11:17:08.905] [warning] [TileContentFactory.cpp:74] No loader registered for tile with content type ‘application/octet-stream’ and magic value '?
LogCesium: Warning: [2021-09-24 11:17:09.109] [warning] [TileContentFactory.cpp:74] No loader registered for tile with content type ‘application/octet-stream’ and magic value '?

Actually, I don’t understand what is possible and what not to do with the Cesium plugin for Unreal.
Some documentation or forums seem contradictory.
It is possible that my lack of knowledge in the field explains my questions.

Can I load terrain (elevation and raster) with this plugin while being offline?

Is the layer.json file generated by Cesium Terrain Builder sufficient or should it be modified?
If it is possible to display my terrain, how do I add the raster to it?