com.atteneder.gltfast Release 6.16.1

Author: atteneder

.gitignore

@@ -14,9 +14,9 @@ Assets/AssetStoreTools*
 # Autogenerated VS/MD/Consulo solution and project files
 ExportedObj/
 .consulo/
-*.csproj
+Projects/**/*.csproj
 *.unityproj
-*.sln
+Projects/**/*.sln
 *.suo
 *.tmp
 *.user
@@ -39,3 +39,20 @@ sysinfo.txt
 
 # Rider
 **/.idea
+
+# Unity tooling
+/upm-ci~
+/test-results~
+/pvp-results
+
+# glTFast test projects
+/Projects/*/ProjectSettings/*
+!Projects/*/ProjectSettings/ProjectVersion.txt
+/Projects/*/UserSettings
+/Projects/*/Assets/Resources*
+/Projects/*/Assets/StreamingAssets*
+/Projects/*/Packages/packages-lock.json
+/Projects/*/Logs
+
+# CI Tols
+Tools/CI/bin

CHANGELOG.md

@@ -4,6 +4,43 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [6.16.1] - 2026-02-19
+
+### Added
+- (Test) *Empty Scene* test asset.
+- (Import) Support for 16-bit mesh indices reduces memory footprint for meshes with less than 65k vertices per sub-mesh.
+  - 16-bit indices are not converted to 32-bit anymore.
+  - 8-bit indices ar converted to 16-bit (instead of 32-bit).
+
+### Changed
+- [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.
+
+### Fixed
+- [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+- Projects depending on an outdated version of [meshoptimizer mesh compression for Unity] may suppress the corresponding compiler error by using the `GLTFAST_IGNORE_MESHOPT_OUTDATED_ERROR`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](https://github.com/atteneder/glTFast/issues/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](https://github.com/atteneder/glTFast/issues/795) and [796](https://github.com/atteneder/glTFast/issues/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](https://github.com/atteneder/glTFast/issues/795) and [796](https://github.com/atteneder/glTFast/issues/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](https://github.com/atteneder/glTFast/issues/791) and [802](https://github.com/atteneder/glTFast/issues/802)).
+- (Export) Texture scaling not preserved on URP/Lit export (fixes [#805](https://github.com/atteneder/glTFast/issues/805)).
+
+### Deprecated
+- Generic built-in/Universal render pipeline [StandardMaterialExport](xref:GLTFast.Export.StandardMaterialExport).
+
 ## [6.16.0] - 2026-01-20
 
 ### Added

Editor/Scripts/GltfImporter.cs

@@ -327,8 +327,8 @@ void ImportScene(
             {
                 throw new InvalidOperationException("Instantiating scene failed");
             }
-            var useFirstChild = true;
-            var multipleNodes = scene.nodes.Length > 1;
+            var useFirstChild = scene.nodes is { Length: > 0 };
+            var singleNode = scene.nodes is { Length: 1 };
             var hasAnimation = false;
 #if UNITY_ANIMATION
             if (importSettings.AnimationMethod != AnimationMethod.None
@@ -341,7 +341,7 @@ void ImportScene(
 #endif
 
             if (instantiationSettings.SceneObjectCreation == SceneObjectCreation.Never
-                || instantiationSettings.SceneObjectCreation == SceneObjectCreation.WhenMultipleRootNodes && !multipleNodes)
+                || instantiationSettings.SceneObjectCreation == SceneObjectCreation.WhenMultipleRootNodes && singleNode)
             {
                 // No scene GameObject was created, so the first
                 // child is the first (and in this case only) node.

Runtime/Scripts/CancellationTokenExtension.cs

@@ -0,0 +1,47 @@
+// SPDX-FileCopyrightText: 2024 Unity Technologies and the glTFast authors
+// SPDX-License-Identifier: Apache-2.0
+
+#if DEBUG && (!UNITY_WEBGL || UNITY_EDITOR)
+#define LOG_CANCELLATION_SOURCE
+#endif
+
+using System;
+using System.Runtime.CompilerServices;
+using System.Threading;
+using UnityEngine;
+
+#if LOG_CANCELLATION_SOURCE
+using System.Diagnostics;
+using System.Reflection;
+#endif
+
+namespace GLTFast
+{
+    static class CancellationTokenExtension
+    {
+#if DEBUG
+        internal static Action s_OnCancellationCheck;
+#endif
+
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        internal static void ThrowIfCancellationRequestedWithTracking(this CancellationToken token)
+        {
+#if DEBUG
+            s_OnCancellationCheck?.Invoke();
+
+            if (token.IsCancellationRequested)
+            {
+#if LOG_CANCELLATION_SOURCE
+                var stackTrace = new StackTrace();
+                // frame 0 is this cancellation method, frame 1 is the target caller
+                if (stackTrace.FrameCount > 1 && stackTrace.GetFrame(1).GetMethod() is MethodInfo methodInfo)
+                    throw new OperationCanceledException($"{methodInfo.DeclaringType}.{methodInfo.Name}", token);
+#endif
+                throw new OperationCanceledException(token);
+            }
+#else // DEBUG
+            token.ThrowIfCancellationRequested();
+#endif // DEBUG
+        }
+    }
+}

Runtime/Scripts/CancellationTokenExtension.cs.meta

@@ -75,7 +75,8 @@ uint[] nodeIndices
             );
 
             var dedicatedSceneEntity = m_Settings.SceneObjectCreation == SceneObjectCreation.Always
-                || m_Settings.SceneObjectCreation == SceneObjectCreation.WhenMultipleRootNodes && nodeIndices.Length > 1;
+                || (m_Settings.SceneObjectCreation == SceneObjectCreation.WhenMultipleRootNodes
+                    && nodeIndices is { Length: > 1 });
 
             if (dedicatedSceneEntity) {
                 var sceneEntity = m_EntityManager.CreateEntity(m_Parent == Entity.Null ? m_SceneArchetype : m_NodeArchetype);

Runtime/Scripts/DOTS/EntityInstantiator.cs

@@ -6,6 +6,7 @@
 #endif
 
 using System;
+using System.Threading;
 using System.Threading.Tasks;
 using Unity.Collections;
 using UnityEngine;
@@ -32,6 +33,7 @@ public static async ValueTask<NativeArray<byte>> DecodeDataUriAsync(
             int startIndex,
             int byteLength,
             IDeferAgent deferAgent,
+            CancellationToken cancellationToken,
             bool timeCritical = false
             )
         {
@@ -42,7 +44,14 @@ public static async ValueTask<NativeArray<byte>> DecodeDataUriAsync(
 #elif GLTFAST_THREADS
             if (!timeCritical || deferAgent.ShouldDefer(predictedTime))
             {
-                return await Task.Run(() => DecodeDataUri(dataUri, startIndex, byteLength));
+                try
+                {
+                    return await Task.Run(() => DecodeDataUri(dataUri, startIndex, byteLength), cancellationToken);
+                }
+                catch (OperationCanceledException)
+                {
+                    cancellationToken.ThrowIfCancellationRequestedWithTracking();
+                }
             }
 #endif
             await deferAgent.BreakPoint(predictedTime);
@@ -66,14 +75,22 @@ public static async ValueTask<byte[]> DecodeDataUriToManagedArrayAsync(
             int startIndex,
             int byteLength,
             IDeferAgent deferAgent,
+            CancellationToken cancellationToken,
             bool timeCritical = false
             )
         {
             var predictedTime = dataUri.Length / (float)k_Base64DecodeSpeed;
 #if GLTFAST_THREADS
             if (!timeCritical || deferAgent.ShouldDefer(predictedTime))
             {
-                return await Task.Run(() => DecodeDataUriToManagedArray(dataUri, startIndex, byteLength));
+                try
+                {
+                    return await Task.Run(() => DecodeDataUriToManagedArray(dataUri, startIndex, byteLength), cancellationToken);
+                }
+                catch (OperationCanceledException)
+                {
+                    cancellationToken.ThrowIfCancellationRequestedWithTracking();
+                }
             }
 #endif
             await deferAgent.BreakPoint(predictedTime);

Runtime/Scripts/DataUri.cs

@@ -0,0 +1,44 @@
+// SPDX-FileCopyrightText: 2026 Unity Technologies and the glTFast authors
+// SPDX-License-Identifier: Apache-2.0
+
+using System;
+using GLTFast.Logging;
+using GLTFast.Schema;
+using UnityEngine;
+
+namespace GLTFast.Export
+{
+    /// <summary>
+    /// Converts Built-In Standard shader based materials to glTF materials
+    /// </summary>
+    public sealed class BuiltInStandardMaterialExport : StandardMaterialExportBase
+    {
+        const string k_KeywordMetallicGlossMap = "_METALLICGLOSSMAP";
+
+        static readonly int k_GlossMapScaleProperty = Shader.PropertyToID("_GlossMapScale");
+
+        /// <summary>
+        /// _Glossiness shader property identifier
+        /// </summary>
+        public static readonly int GlossinessProperty = Shader.PropertyToID("_Glossiness");
+
+        protected override bool HasMetallicGlossMap(UnityEngine.Material uMaterial)
+        {
+            return uMaterial.IsKeywordEnabled(k_KeywordMetallicGlossMap);
+        }
+
+        protected override bool IsPbrMetallicRoughness(UnityEngine.Material material)
+        {
+            return material.HasProperty(MetallicProperty)
+                && (
+                    HasMetallicGlossMap(material)
+                    || material.HasProperty(GlossinessProperty)
+                );
+        }
+
+        protected override int GetSmoothnessProperty(bool sourceAlbedoAlpha, bool hasMetallicGlossinessMap)
+        {
+            return sourceAlbedoAlpha || hasMetallicGlossinessMap ? k_GlossMapScaleProperty : GlossinessProperty;
+        }
+    }
+}

Runtime/Scripts/Export/BuiltInStandardMaterialExport.cs

@@ -7,7 +7,7 @@ namespace GLTFast.Export
 {
     static class Constants
     {
-        public const string version = "6.16.0";
+        public const string version = "6.16.1";
 
         internal const string mimeTypePNG = "image/png";
         internal const string mimeTypeJPG = "image/jpeg";