com.unity.cloud.gltfast 6.16.1 Package Notes

✨ Features

(Test) *Empty Scene* test asset.

📈 Improvements

[GltfImport.Load](xref:GLTFast.GltfImportBase.Load*), [GltfImport.InstantiateSceneAsync](xref:GLTFast.GltfImportBase.InstantiateSceneAsync*) and their variants now throw an `OperationCanceledException` when cancelled before completion.
Replaced the generic [StandardMaterialExport](xref:GLTFast.Export.StandardMaterialExport) with specializations.
- [LitMaterialExport](xref:GLTFast.Export.LitMaterialExport) for Universal Render Pipeline Lit shader material export.
- [BuiltInStandardMaterialExport](xref:GLTFast.Export.BuiltInStandardMaterialExport) for Built-in Render Pipeline Standard shader material export.
(Performance) Improved performance of mesh indices conversion for draw modes line loop, triangle strips and triangle fan.

🔧 Bug Fixes

[GltfImport.InstantiateSceneAsync](xref:GLTFast.GltfImportBase.InstantiateSceneAsync*) properly handles an invalid scene index parameter.
[GltfImport](xref:GLTFast.GltfImportBase) waits for downloads to complete before attempting disposal during cancellation.
Projects depending on an outdated version of [meshoptimizer mesh compression for Unity] may suppress the corresponding compiler error by using the `GLTFAST_IGNORE_MESHOPT_OUTDATED_ERROR` scripting define symbol.
(Shader) Incorrect alpha blending/clipping due to invalid color space conversion on the base color map alpha and vertex color alpha values (affected shader graphs only; fixes #800).
(Shader) Built-in render pipeline shaders metallic-roughness and specular-glossiness now factor in vertex color alpha values.
(Shader) All built-in render pipeline shaders apply vertex color alpha values linearly.
(Shader) Shader graph *glTF-pbrSpecularGlossiness* does not disregard the *Glossiness* parameter anymore.
(Import) Cases when specular-glossiness material setup would be incomplete at runtime.
(Import) Removed remains of incorrectly signed integer indices.
(Export) Smoothness value property is exported correctly across more combination of settings for Universal Render Pipeline Lit shader based materials (fixes #795 and 796).
(Export) When a Lit/Standard material has a smoothness texture, their smoothness value is baked into the resulting roughness channel (of the ORM map). This preserves the visual appearance, but is a lossy operation if the smoothness value is not `1.0` (fixes #795 and 796).
(Export) `MetaMaterialExportBuiltIn` is used for built-in material export (unless `GLTFAST_BUILTIN_SHADER_GRAPH` is set).
(Import) Solved exception when scenes with no nodes are loaded.
(Import) Triangle fan meshes with the center vertex not being the first vertex import correctly now.
(Test) Graphics tests are more stable/consistent due to dedicated scene.
(Shader) Incorrect normal unpacking when using default normal map on Android (fixes #791 and 802).
(Export) Texture scaling not preserved on URP/Lit export (fixes #805).
### Deprecated
Generic built-in/Universal render pipeline [StandardMaterialExport](xref:GLTFast.Export.StandardMaterialExport).