ArgumentOutOfRangeException when export model（GltfWriter.cs

[zhuYouFu]

Describe the bug
ArgumentOutOfRangeException when export model（GltfWriter.cs）

ArgumentOutOfRangeException: Specified argument was out of the range of valid values.
Parameter name: stream out of bounds, should be below 0 but was 0
at UnityEngine.Mesh+MeshData.GetVertexData[T] (System.Int32 stream) [0x00038] in <6c435a1487b44af8a1e8ac5a6d175b15>:0
at GLTFast.Export.MeshDataProxy`1[TIndex].GetVertexData (System.Int32 stream) [0x00000] in <24458e2b5ca44187bdccd3093e29063c>:0
at GLTFast.Export.GltfWriter.BakeMesh (System.Int32 meshId, GLTFast.Export.IMeshData meshData) [0x0073e] in <24458e2b5ca44187bdccd3093e29063c>:0
at GLTFast.Export.GltfWriter.BakeMeshes () [0x00295] in <24458e2b5ca44187bdccd3093e29063c>:0
at GLTFast.Export.GltfWriter.Bake (System.String bufferPath, System.String directory) [0x00082] in <24458e2b5ca44187bdccd3093e29063c>:0
at GLTFast.Export.GltfWriter.SaveAndDispose (System.IO.Stream outStream, System.String bufferPath, System.String directory) [0x000b5] in <24458e2b5ca44187bdccd3093e29063c>:0
at GLTFast.Export.GltfWriter.SaveToFileAndDispose (System.String path) [0x000f8] in <24458e2b5ca44187bdccd3093e29063c>:0
at GLTFast.Export.GameObjectExport.SaveToFileAndDispose (System.String path, System.Threading.CancellationToken cancellationToken) [0x00073] in <24458e2b5ca44187bdccd3093e29063c>:0
at GltfastExporter.ExportToGlbAsync (UnityEngine.GameObject go, System.String fileName, System.Boolean enableCompression) [0x0013f] in <86d77238c4df4c7cb81ccf02385747ed>:0
at Tsl.ModelStudio.Managers.ExportManager.ExportSpaceToGlbAsync (Tsl.ModelStudio.LivingSpace space, System.String fileName, System.Boolean enableCompression) [0x001c7] in :0
at Tsl.ModelStudio.Managers.ExportManager.PublishSpaceAsync (System.String targetFolder, Tsl.ModelStudio.LivingSpace space, System.Boolean recursive, System.Boolean hideModels) [0x009aa] in :0
at Tsl.ModelStudio.Editors.PublishAllSubSpacesCommand.Invoke () [0x000b6] in :0
Files

To Reproduce
Steps to reproduce the behavior:
1.Export the scene model during runtime.
2.An exception is thrown intermittently.

** Fix**
I have fixed this issue in the following files, with changes made at line 1164 and lines 1240-1249.

GltfWriter.txt

Desktop (please complete the following information):

• glTFast version [6.14.1]
• Unity Editor version [2022.3.41f1c1]
• Render Pipeline and version [Universal Render Pipeline 14.0.11]
• Platform: [Editor, Windows Player]

[jdebelle-unity]

Thank you for reporting this. We'll be looking into it and keeping you posted.

A few follow-up questions as we look into this:

1. What makes it intermittent? Since it happens inconsistently, what are the differences between:

   • Meshes that export successfully vs. those that fail?
   • Scene configurations that work vs. those that don't?
   • Does it correlate with specific object types, mesh complexity, or scene hierarchy depth?

2. What's the simplest scene/object that triggers this issue?

3. Can I ask you to open a PR with the proposed changes? This will make it easier to track against the previous implementation.

[anonymous2585]

I got exactly the same issue on some of our models today, after updating from 6.0.1 to 6.16.1.

Our original FBX is dirty, I noticed the meshes where the exception happen are meshes with 0 vertices (thus 0 triangles).

I think glTFast should skip mesh creation in the gltf when a Unity mesh is empty. I fixed it that way:

com.unity.cloud.gltfast/Packages/com.unity.cloud.gltfast/Runtime/Scripts/Export/GameObjectExport.cs

Line 292 in 472dc48

if (mesh != null)

This fix is not perfect: if the Unity mesh carry a material, the material will be put in the gltf file even if it is unused. It was correct in 6.0.1.

[nickconstantinidis]

This should now be fixed in 6.17.0, please let us know if this issue still occurs. The culprit was indeed meshes with zero vertices.