Cesium ion terrain dataset structure

Im trying to download and use a terrain tilset from cesium ion in unreal engine.
It works fine when using cesium ion as source, but downloading the tileset and using it as a local source or placing it on a server doesent work.

It seems as if the folder structure cesium for unreal expects is different from what exported from cesium ion.

From unreal output log:
LogCesium: Error: [2025-11-19 20:57:56.626] [error] [ErrorList.h:89] Errors loading quantized mesh terrain:
Received status code 404 for tile content file:///simplfiedPath/markmodell/0/0/0.terrain?v=1.1.0&extensions=octvertexnormals-metadata
LogCesium: Error: [2025-11-19 20:57:56.626] [error] [ErrorList.h:89] Errors loading quantized mesh terrain:
Received status code 404 for tile content file:///simplfiedPath/markmodell/0/1/0.terrain?v=1.1.0&extensions=octvertexnormals-metadata

404 is very reasonable since
file:///simplfiedPath/markmodell/0
does not exist, the first folder is named 0-1

Thought changing the folder name to 0 in the dataset could work but it looks for other folders that doesent exist either

LogCesium: Error: [2025-11-19 21:07:58.046] [error] [ErrorList.h:89] Errors loading quantized mesh terrain:
Received status code 404 for tile content file:///simplfiedPath/markmodell/0/0/0.terrain?v=1.1.0&extensions=octvertexnormals-metadata

But the first 0.terrain should be accessed from:
simplfiedPath\markmodell\0\0\0\0.terrain

I dont know if it helps, but its the asset id on my cesium ion account: 3647182

Any clues on how to handle this missmatch in what cesium unreal expects and what can be exported from cesium ION?

Other datasets with buildings and such seems to work fine.

So, if anyone else has similar issues, it was an easy fix.

The cesium ion export simply put in an extra folder compared to what was expected in unreal.
ion export: datasetFolder/0-1/0/0/0.terrain
expected: datasetFolder/0/0/0.terrain

Everything worked great just removing the 0-1 folder, moving its content up one step in the folder structure. Easy peasy.

Hi,

This seems to be a bug on Cesium ion. The archiving process shouldn’t prefix the 0-1 portion. We have been made aware of this bug and are actively working on fixing it.

Thanks,
Ankit

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