Cartographic Polygon to crop the 3dtile layer

Cesium for Unreal
1

I use Cartographic Polygon to crop the 3dtile layer, and the model at the clipping position rotates when I get close to the model. I don’t know if it is my 3dtile resource problem or other problems. Where should I look for the problem? Thanks
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2

Just to confirm, this only happens when you use the cartographic polygon?

Can you share the Unreal Engine + Cesium for Unreal versions that you’re using? It would also help if you were able to share the relevant data so we could try to reproduce.

3

Yes, only when using cartographic polygon, UE5.1.1 version, Cesium for Unreal 1.27, the data is a simple white membrane model

4

Are you able to share this tileset with us? Or another tileset that exhibits the same problem? My guess is that it’s triggering a bug in the upsampling code, but we’ll need to be able to reproduce it to confirm.

5

Thanks for the reply, this is my cesium ion test resource, defaultAccessToken: eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJqdGkiOiIzNjU4ZWEyNC0zOTdkLTQwYjktOTE1OS05N2VmNzJmMzgxYTUiLCJpZCI6MjQ3MDUsInNjb3BlcyI6WyJhc2wiLCJhc3IiLCJhc3ciLCJnYyIsInByIl0sImlhdCI6MTU4NTYzNzc0OX0.z2On6AXPBHbgUyn8l8IqjkWkxeNi43ULycbyWaXJDxg, AssetId: 1891778

6

The problem is that this tileset uses the gltfUpAxis property in its tileset.json. And we don’t correctly account for this when upsampling the tile, so it ends up rotated 90 degrees. I wrote a bug to cover this:

However, because gltfUpAxis is not actually part of the 3D Tiles specification, it’s probably not going to get very high priority from us at Cesium. We welcome a pull request to fix it, though.

Or, you might prefer to reach out to cesiumlab and ask them to produce tilesets that conform to the 3D Tiles specification. Despite the trademark violation, cesiumlab is not affiliated with us in any way.

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