Load 3D Tiles from external sources to Unreal

Dear cesium team

I am trying to load tiles from an external source into Unreal Engine. I was assuming that if you define an url to the dataset, the Cesium iON asset id will be ignored.

This are the tilesets I would like to use:

I am aware that they are generated with an older Cesium 3D Tiles spec and so I expect that they might not be displayed in Unreal. But I can’t see Unreal accessing the resource with Fiddler (checking http traffic between my machine and remote locations).

thanks for your help!

The respective resource might not be accessed because the tileset is not in the view frustum of the camera (edit: although it should at least access the top-level tileset.json file. If this is not happening: Is there any output on the Developer Log of the Unreal Editor?). Double-clicking the tileset in the World Outliner should center the tileset in the view, and cause the requests for the tile data to be sent out.

But… the data indeed seems to be based on an old version. Specifically, the B3DM files of the tileset seem to contain glTF 1.0 data, because it prints error messages

LogCesium: Error: [2021-04-17 13:44:35.306] [error] [GltfContent.cpp:30] Failed to load binary glTF from https://vectortiles0.geo.admin.ch/3d-tiles/ch.swisstopo.swisstlm3d.3d/20201020/5/18/14.b3dm:
- Only binary glTF version 2 is supported, found version 1

It could be possible to upgrade the tileset, using the upgrade functionality from 3d-tiles-validator/tools at 2.0-tools · CesiumGS/3d-tiles-validator · GitHub (note that this specific branch has to be used), but there might still be an issue with the resulting glTF data, which is currently investigated.

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thanks @Marco13, yes I can see these logs, too. THere should be an update of their tilesets in the near future, so I am looking forward to it and will work with the Cesium tilesets in the meantime:)