Made some more methods AOT friendly.

src/SharpGLTF.Toolkit/Geometry/MeshBuilderToolkit.cs

@@ -74,7 +74,7 @@ public interface IMeshBuilder<TMaterial>
         void Validate();
     }
 
-    static class MeshBuilderToolkit
+    static partial class MeshBuilderToolkit
     {
         public static VertexBuilder<VertexGeometryDelta, VertexMaterialDelta, VertexEmpty>[] GetMorphTargetVertices(this IPrimitiveMorphTargetReader morphTarget, int vertexCount)
         {
@@ -115,6 +115,7 @@ public static Schema2.EncodingType GetOptimalJointEncoding<TMaterial>(this IEnum
 
             return maxIndex < 256 ? Schema2.EncodingType.UNSIGNED_BYTE : Schema2.EncodingType.UNSIGNED_SHORT;
         }
+
 
         public static IMeshBuilder<TMaterial> CreateMeshBuilderFromVertexAttributes
             <
@@ -123,31 +124,12 @@ public static IMeshBuilder<TMaterial> CreateMeshBuilderFromVertexAttributes
             #endif
             TMaterial>(params string[] vertexAttributes)
         {
-            Type meshType = GetMeshBuilderType(typeof(TMaterial), vertexAttributes);
-
-            var mesh = Activator.CreateInstance(meshType, string.Empty);
-
-            return mesh as IMeshBuilder<TMaterial>;
-        }
-
-        #if NET6_0_OR_GREATER
-        [return: DynamicallyAccessedMembers(DynamicallyAccessedMemberTypes.PublicConstructors)]
-        #endif
-        public static Type GetMeshBuilderType
-            (
-            #if NET6_0_OR_GREATER
-            [DynamicallyAccessedMembers(DynamicallyAccessedMemberTypes.PublicConstructors)]
-            #endif
-            Type materialType, string[] vertexAttributes)
-        {
-            var tvg = VertexUtils.GetVertexGeometryType(vertexAttributes);
-            var tvm = VertexUtils.GetVertexMaterialType(vertexAttributes);
-            var tvs = VertexUtils.GetVertexSkinningType(vertexAttributes);
-
-            var meshType = typeof(MeshBuilder<,,,>);
-
-            return meshType.MakeGenericType(materialType, tvg, tvm, tvs);
-        }
+            return VertexUtils
+                .GetVertexBuilderType(vertexAttributes) // get a vertex factory from attributes
+                .BuilderFactory                         
+                .Invoke()                               // create a single vertex
+                .CreateCompatibleMesh<TMaterial>();     // create a mesh with the given vertex format.
+        }        
 
         public static IReadOnlyDictionary<Vector3, Vector3> CalculateSmoothNormals<TMaterial>(this IMeshBuilder<TMaterial> srcMesh)
         {

src/SharpGLTF.Toolkit/Geometry/PrimitiveBuilder.cs

@@ -111,6 +111,8 @@ protected PrimitiveBuilder(MeshBuilder<TMaterial, TvG, TvM, TvS> mesh, Primitive
         #endif
         public Type VertexType => typeof(VertexBuilder<TvG, TvM, TvS>);
 
+        public Func<IVertexBuilder> VertexFactory => () => new VertexBuilder<TvG, TvM, TvS>();
+
         /// <summary>
         /// Gets the list of vertices used by this primitive.
         /// </summary>

src/SharpGLTF.Toolkit/Geometry/PrimitiveInterfaces.cs

@@ -79,6 +79,7 @@ public interface IPrimitiveBuilder
         [System.Diagnostics.CodeAnalysis.DynamicallyAccessedMembers(System.Diagnostics.CodeAnalysis.DynamicallyAccessedMemberTypes.PublicConstructors)]
         #endif
         Type VertexType { get; }
+        Func<IVertexBuilder> VertexFactory { get; }
 
         void SetVertexDelta(int morphTargetIndex, int vertexIndex, VertexGeometryDelta geometryDelta, VertexMaterialDelta materialDelta);
 

src/SharpGLTF.Toolkit/Geometry/VertexBufferColumns.cs

@@ -169,10 +169,12 @@ private void _ApplyTransform(Transforms.IGeometryTransform transform)
             this.Positions = _IsolateColumn(this.Positions); // Position, normal and tangent can be modified by morphing and skinning
             this.Normals = _IsolateColumn(this.Normals);
             this.Tangents = _IsolateColumn(this.Tangents);
-            this.Colors0 = _IsolateColumn(this.Colors0);     // colors0,1 and texCoords0,1 can be modified by morphing
+            this.Colors0 = _IsolateColumn(this.Colors0);     // colors0,1 and texCoords 0,1,2,3 can be modified by morphing
             this.Colors1 = _IsolateColumn(this.Colors1);
             this.TexCoords0 = _IsolateColumn(this.TexCoords0);
             this.TexCoords1 = _IsolateColumn(this.TexCoords1);
+            this.TexCoords2 = _IsolateColumn(this.TexCoords2);
+            this.TexCoords3 = _IsolateColumn(this.TexCoords3);
 
             // prepare animation data, if available
 
@@ -185,6 +187,8 @@ private void _ApplyTransform(Transforms.IGeometryTransform transform)
             Vector4[] morphColors1 = null;
             Vector2[] morphTexcrd0 = null;
             Vector2[] morphTexcrd1 = null;
+            Vector2[] morphTexcrd2 = null;
+            Vector2[] morphTexcrd3 = null;
 
             if (_MorphTargets != null)
             {
@@ -195,6 +199,8 @@ private void _ApplyTransform(Transforms.IGeometryTransform transform)
                 if (_MorphTargets.All(item => item.Colors1 != null)) morphColors1 = new Vector4[this.MorphTargets.Count];
                 if (_MorphTargets.All(item => item.TexCoords0 != null)) morphTexcrd0 = new Vector2[this.MorphTargets.Count];
                 if (_MorphTargets.All(item => item.TexCoords1 != null)) morphTexcrd1 = new Vector2[this.MorphTargets.Count];
+                if (_MorphTargets.All(item => item.TexCoords2 != null)) morphTexcrd2 = new Vector2[this.MorphTargets.Count];
+                if (_MorphTargets.All(item => item.TexCoords3 != null)) morphTexcrd3 = new Vector2[this.MorphTargets.Count];
             }
 
             // loop over every vertex
@@ -252,6 +258,18 @@ private void _ApplyTransform(Transforms.IGeometryTransform transform)
                         _FillMorphData(morphTexcrd1, vc => vc.TexCoords1[i]);
                         TexCoords1[i] = morphMaterial.MorphTexCoord(TexCoords1[i], morphTexcrd1);
                     }
+
+                    if (this.TexCoords2 != null)
+                    {
+                        _FillMorphData(morphTexcrd2, vc => vc.TexCoords2[i]);
+                        TexCoords1[2] = morphMaterial.MorphTexCoord(TexCoords2[i], morphTexcrd2);
+                    }
+
+                    if (this.TexCoords3 != null)
+                    {
+                        _FillMorphData(morphTexcrd3, vc => vc.TexCoords3[i]);
+                        TexCoords3[2] = morphMaterial.MorphTexCoord(TexCoords3[i], morphTexcrd3);
+                    }
                 }
             }
 
@@ -318,11 +336,8 @@ public VertexBufferColumns AddMorphTarget()
         #endregion
 
         #region API - Vertex indexing
-
-        #if NET6_0_OR_GREATER
-        [return: System.Diagnostics.CodeAnalysis.DynamicallyAccessedMembers(System.Diagnostics.CodeAnalysis.DynamicallyAccessedMemberTypes.PublicConstructors)]
-        #endif
-        public Type GetCompatibleVertexType()
+
+        public (Type BuilderType, Func<IVertexBuilder> BuilderFactory) GetCompatibleVertexType()
         {
             var hasNormals = Normals != null;
             var hasTangents = hasNormals && Tangents != null;
@@ -394,21 +409,15 @@ private TvS GetVertexSkinning<TvS>(int index)
             }
 
             return s;
-        }
+        }        
 
-        public IVertexBuilder GetVertex
-            (
-            #if NET6_0_OR_GREATER
-            [System.Diagnostics.CodeAnalysis.DynamicallyAccessedMembers(System.Diagnostics.CodeAnalysis.DynamicallyAccessedMemberTypes.PublicConstructors)]
-            #endif
-            Type vertexType,
-            int index)
+        public IVertexBuilder GetVertex(Func<IVertexBuilder> factory, int index)
         {
             var g = GetVertexGeometry<VertexPositionNormalTangent>(index);
             var m = GetVertexMaterial<VertexColor2Texture2>(index);
             var s = GetVertexSkinning<VertexJoints8>(index);
 
-            return new VertexBuilder(g, m, s).ConvertToType(vertexType);
+            return new VertexBuilder(g, m, s).ConvertToType(factory);
         }
 
         public VertexBuilder<TvG, TvM, VertexEmpty> GetVertex<TvG, TvM>(int index)

src/SharpGLTF.Toolkit/Geometry/VertexBuilder.cs

@@ -33,6 +33,9 @@ public interface IVertexBuilder
         /// </summary>
         /// <param name="skinning">A <see cref="IVertexSkinning"/> set.</param>
         void SetSkinning(IVertexSkinning skinning);
+
+
+        IMeshBuilder<TMaterial> CreateCompatibleMesh<TMaterial>(string name = null);
     }
 
     /// <summary>
@@ -331,6 +334,11 @@ public static MeshBuilder<TvG, TvM, TvS> CreateCompatibleMesh(string name = null
             return new MeshBuilder<TvG, TvM, TvS>(name);
         }
 
+        IMeshBuilder<TMaterial> IVertexBuilder.CreateCompatibleMesh<TMaterial>(string name)
+        {
+            return new MeshBuilder<TMaterial, TvG, TvM, TvS>(name);
+        }
+
         #pragma warning restore CA1000 // Do not declare static members on generic types
 
         readonly IVertexGeometry IVertexBuilder.GetGeometry() { return this.Geometry; }
@@ -449,7 +457,7 @@ public readonly VertexBuilder<TvG, TvM, TvS> WithSkinning(IEnumerable<(int Index
             v.Skinning.SetBindings(sparse);
 
             return v;
-        }
+        }        
 
         #endregion
     }
@@ -496,17 +504,11 @@ public VertexBuilder(IVertexGeometry g, IVertexMaterial m, IVertexSkinning s)
 
         public void SetMaterial(IVertexMaterial material) { this.Material = material; }
 
-        public void SetSkinning(IVertexSkinning skinning) { this.Skinning = skinning; }
+        public void SetSkinning(IVertexSkinning skinning) { this.Skinning = skinning; }        
 
-        public readonly IVertexBuilder ConvertToType
-            (
-            #if NET6_0_OR_GREATER
-            [System.Diagnostics.CodeAnalysis.DynamicallyAccessedMembers(System.Diagnostics.CodeAnalysis.DynamicallyAccessedMemberTypes.PublicConstructors)]
-            #endif
-            Type vertexType
-            )
+        public readonly IVertexBuilder ConvertToType(Func<IVertexBuilder> factory)
         {
-            var v = (IVertexBuilder)Activator.CreateInstance(vertexType);
+            var v = factory.Invoke();
 
             v.SetGeometry(Geometry);
             v.SetMaterial(Material);
@@ -515,6 +517,11 @@ Type vertexType
             return v;
         }
 
+        IMeshBuilder<TMaterial> IVertexBuilder.CreateCompatibleMesh<TMaterial>(string name)
+        {
+            throw new NotImplementedException();
+        }
+
         #endregion
     }
 }