Issues with 3D tileset that works fine in CesiumJS

Cesium for Unity
1

Hello everyone,

we’re currently trying to get a 3D-tileset containing trees (in the literal sense of the word :)) working in Unity.

When we tested the dataset using Cesium Sandcastle, everything worked fine as you can see in the screenshot below.

Bildschirmfoto 2025-06-30 um 11.11.36
Bildschirmfoto 2025-06-30 um 11.11.361920×1367 270 KB

Here’s the JavaScript we used to test this:

const viewer = new Cesium.Viewer("cesiumContainer");
const tilesetArea2 = await Cesium.Cesium3DTileset.fromUrl("https://daten-hamburg.de/gdi3d/datasource-data/LoD3_tex20cm_Area1/tileset.json");
const trees = await Cesium.Cesium3DTileset.fromUrl("https://daten-hamburg.de/gdi3d/datasource-data/Strassenbaumkataster_Sommerbaeume/tileset.json");
viewer.terrainProvider = await Cesium.ArcGISTiledElevationTerrainProvider.fromUrl("https://elevation3d.arcgis.com/arcgis/rest/services/WorldElevation3D/Terrain3D/ImageServer");
viewer.scene.primitives.add(tilesetArea2);
viewer.scene.primitives.add(trees);
 
await trees.readyPromise;
await viewer.zoomTo(tilesetArea2);

In Unity however, the trees are misplaced and rotated or not visible at all. Our first guess was that the CRS of the dataset might be incompatible.

Bildschirmfoto 2025-06-30 um 11.30.01
Bildschirmfoto 2025-06-30 um 11.30.011920×951 260 KB

Any hint how to resolve this would be greatly appreciated!

Kind regards

David

2

This is very likely another … instance… of the issue that instancing is not yet supported in Cesium For Unity: Instanced (i3dm) tilesets in Unity

So I assume that the tileset contains these trees as I3DM or glTF with EXT_mesh_gpu_instancing, which are not yet supported.

1 Like
3

Thanks for the reply Marco!

The trees are in fact contained as I3DM, while the actual meshes seem to be referenced from external GLBs.
Can you guide me on how i might verify whether EXT_mesh_gpu_instancing is in fact enabled?

4

I’m not sure if I understood that question. Instances (like the trees) can be represented with I3DM. An alternative way of creating such instances is to use glTF with theEXT_mesh_gpu_instancing extension.

Both approaches are ~“largely equivalent” in terms of the functionality. But both approaches require support for instancing in Cesium For Unity.

5

Thanks for the clarification.
It does seem to be the cause of our problems. Since this is already being tracked, i’ll mark this post as solved.