Unity crashes when loading a 3D Tile from URL

[Luizfelm]

Unity crashes when trying to load a 3D Tile directly from a URL. The tileset is loaded through an API using a tileset.json file. After setting the URL in the Unity 3DTileset component, the editor crashes immediately.

Checking the Editor.log, I found the following error:

[2025-01-28 12:23:06.433] [warning] [TilesetContentManager.cpp:609] Warning when resolving external gltf buffers from https://d143ryb2ii5d8n.cloudfront.net/9573...eb12/10-0.glb

• Could not load the external glTF buffer: https://d143ryb2ii5d8n.cloudfront.net/9573...eb12/textures/generated/metallicRoughnessTexture.png
• Errors while loading external glTF buffer: https://d143ryb2ii5d8n.cloudfront.net/9573...eb12/textures/generated/metallicRoughnessTexture.png
• Request for https://d143ryb2ii5d8n.cloudfront.net/9573...eb12/textures/generated/metallicRoughnessTexture.png failed with code 403

[Luizfelm]

In addition to the error related to loading the glTF buffer, the following warning appears in the log:

"Detected one or more triangles where the distance between any 2 vertices is greater than 500 units. The resulting Triangle Mesh can impact simulation and query stability. It is recommended to tessellate meshes that have large triangles. Source mesh name:
UnityEngine.Physics:BakeMesh (int,bool)
Reinterop.ReinteropInitializer:UnityEngine_Physics_CallBakeMesh_dUTFInDZC08B3wpYvm01lw (int,byte) (at ./Library/PackageCache/com.cesium.unity/Runtime/generated/Reinterop.RoslynSourceGenerator/ReinteropInitializer.cs:65076)
Reinterop.ReinteropInitializer/ActionNativeFunction:Invoke () (at ./Library/PackageCache/com.cesium.unity/Runtime/generated/Reinterop.RoslynSourceGenerator/ReinteropInitializer.cs:59757)
System.Threading._ThreadPoolWaitCallback:PerformWaitCallback ()"

[kring]

Hi @Luizfelm, is it correct that the metallicRoughnessTexture.png is returning a 403 error? That shouldn't cause a crash in any case, but that will give us a place to start looking. Also, can you confirm what version of Cesium for Unity you're using? If you can provide me with the full URL of this tileset (privately is fine), I can take a closer look a what's going wrong.

[Luizfelm]

Hi @kring ,

After testing the same tileset in different versions of Cesium for Unity and also in Unreal (both via URL), I confirmed that the errors are caused by the tileset itself, not Cesium.

However, any version of Cesium for Unity above 1.13.0 crashes when trying to open the models, while versions 1.13.0 and below work perfectly.

With this finding, you can consider this issue closed.

Thanks for your support!

[kring]

Thanks for the update @Luizfelm. I'm going to reopen this until I have a chance to try out the model you send me separately, though. A crash is worth fixing, even if it's caused by a broken model. Especially if it's a regression from previous versions.

[Luizfelm]

Hi all,

I just retested this over the last couple of days (on version 1.15.5) and everything is working really well now. Thank you so much for diving in on this—I really appreciate your help and the quick turnaround!

Feel free to close this issue unless there’s anything else you’d like me to verify.

Best,
Luiz