UnityMeshData.MorphTargetNormals[i] may need to check null on Import

[FujiSunflower]

Problem

UnityMeshData.MorphTargetNormals[i] may need to check null on import.

UnityGLTF/Runtime/Scripts/SceneImporter/ImporterMeshes.cs

Line 908 in d9ed104

tarAttrNorm.AccessorContent.AsVec3s.ToUnityVector3Raw(unityData.MorphTargetNormals[i], (int)vertOffset);

References

It is because the array has null check on AddBlendShapesToMesh in ConstructUnityMesh.

UnityGLTF/Runtime/Scripts/SceneImporter/ImporterMeshes.cs

Line 554 in d9ed104

private void AddBlendShapesToMesh(UnityMeshData unityMeshData, int meshIndex, Mesh mesh)

[pfcDorn]

I don't think this is needed, because we already check if there is a attribute for the morphtargetnormals.
Or do you have a gltf file which cause an error there?

[FujiSunflower]

Ah, I tried to import ".glb" file changed suffix from ".vrm". It happened this error.
Perhaps, VRM format has any wrong as glTF. VRM is the format based on glTF. So VRM has to change GLB.
GLB : Seed-san.zip

NullReferenceException: Object reference not set to an instance of an object
UnityGLTF.GLTFSceneImporter.ConvertAttributeAccessorsToUnityTypes (UnityGLTF.Cache.MeshCacheData+PrimitiveCacheData primData, UnityGLTF.UnityMeshData unityData, System.UInt32 vertOffset, System.Int32 indexOffset) (at Library/PackageCache/org.khronos.unitygltf@4ebe065f27/Runtime/Scripts/SceneImporter/ImporterMeshes.cs:908)
UnityGLTF.GLTFSceneImporter.ConstructMesh (GLTF.Schema.GLTFMesh mesh, System.Int32 meshIndex, System.Threading.CancellationToken cancellationToken) (at Library/PackageCache/org.khronos.unitygltf@4ebe065f27/Runtime/Scripts/SceneImporter/ImporterMeshes.cs:120)
UnityGLTF.GLTFSceneImporter.ConstructNode (GLTF.Schema.Node node, System.Int32 nodeIndex, System.Threading.CancellationToken cancellationToken) (at Library/PackageCache/org.khronos.unitygltf@4ebe065f27/Runtime/Scripts/GLTFSceneImporter.cs:809)
UnityGLTF.GLTFSceneImporter.GetNode (System.Int32 nodeId, System.Threading.CancellationToken cancellationToken) (at Library/PackageCache/org.khronos.unitygltf@4ebe065f27/Runtime/Scripts/GLTFSceneImporter.cs:771)
UnityGLTF.GLTFSceneImporter.ConstructScene (GLTF.Schema.GLTFScene scene, System.Boolean showSceneObj, System.Threading.CancellationToken cancellationToken) (at Library/PackageCache/org.khronos.unitygltf@4ebe065f27/Runtime/Scripts/GLTFSceneImporter.cs:1087)
UnityGLTF.GLTFSceneImporter._LoadScene (System.Int32 sceneIndex, System.Boolean showSceneObj, System.Threading.CancellationToken cancellationToken) (at Library/PackageCache/org.khronos.unitygltf@4ebe065f27/Runtime/Scripts/GLTFSceneImporter.cs:623)
UnityGLTF.GLTFSceneImporter.LoadSceneAsync (System.Int32 sceneIndex, System.Boolean showSceneObj, System.Action`2[T1,T2] onLoadComplete, System.Threading.CancellationToken cancellationToken, System.IProgress`1[T] progress) (at Library/PackageCache/org.khronos.unitygltf@4ebe065f27/Runtime/Scripts/GLTFSceneImporter.cs:425)
UnityGLTF.AsyncHelpers+<>c__DisplayClass0_0.<RunSync>b__0 (System.Object _) (at Library/PackageCache/org.khronos.unitygltf@4ebe065f27/Editor/Scripts/Internal/AsyncHelpers.cs:30)
Rethrow as AggregateException: AsyncHelpers.Run method threw an exception. (Object reference not set to an instance of an object)
UnityGLTF.AsyncHelpers+ExclusiveSynchronizationContext.BeginMessageLoop () (at Library/PackageCache/org.khronos.unitygltf@4ebe065f27/Editor/Scripts/Internal/AsyncHelpers.cs:130)
UnityGLTF.AsyncHelpers.RunSync (System.Func`1[TResult] task) (at Library/PackageCache/org.khronos.unitygltf@4ebe065f27/Editor/Scripts/Internal/AsyncHelpers.cs:37)
UnityGLTF.GLTFImporter.CreateGLTFScene (UnityGLTF.Plugins.GLTFImportContext context, UnityEngine.GameObject& scene, UnityEngine.AnimationClip[]& animationClips, UnityGLTF.GLTFSceneImporter& importer) (at Library/PackageCache/org.khronos.unitygltf@4ebe065f27/Editor/Scripts/GLTFImporter.cs:867)
UnityGLTF.GLTFImporter.OnImportAsset (UnityEditor.AssetImporters.AssetImportContext ctx) (at Library/PackageCache/org.khronos.unitygltf@4ebe065f27/Editor/Scripts/GLTFImporter.cs:296)
UnityEngine.Debug:LogException(Exception)
UnityGLTF.GLTFImporter:OnImportAsset(AssetImportContext) (at Library/PackageCache/org.khronos.unitygltf@4ebe065f27/Editor/Scripts/GLTFImporter.cs:741)
UnityEditor.AssetImporters.ScriptedImporter:GenerateAssetData(AssetImportContext)
UnityEditorInternal.InternalEditorUtility:ProjectWindowDrag(HierarchyProperty, Boolean)
UnityEngine.GUIUtility:ProcessEvent(Int32, IntPtr, Boolean&)

Refererence

https://github.com/vrm-c/vrm-specification/blob/master/samples/Seed-san/vrm/Seed-san.vrm

[pfcDorn]

Ah...i see....not all Targets have a normal blendshape. We currently check only for the first one. Need some more changes i guess. I will take an eye of it next week !

[hybridherbst]

@FujiSunflower out of curiosity, where was that file created / what software was it created with?

[FujiSunflower]

Maybe it was made by UniVRM as Refererence's url. I re-tested by UniVRM. I found the file uses Sparse Accessor.
If UniVRM use no Sparse Accessor, the file is success.
If UniVRM use Sparse Accessor, the file is failure.
And the file can import by glTFast.
Perhaps UniVRM has any problem in Sparse Accessor. But I don't know the detail.
UniVRM : https://github.com/vrm-c/UniVRM

[hybridherbst]

Thank you! I believe the file is perfectly valid, it's just unusual that some blend shapes include normals and others not, so was curious where it comes from / what the reasoning is.