small fixes to schema2

WIP trying to figure out morph transform (again)

src/SharpGLTF.Core/Schema2/gltf.Images.cs

@@ -84,6 +84,21 @@ namespace SharpGLTF.Schema2
         /// </summary>
         public bool IsWebp => GetImageContent()._IsWebpImage();
 
+        /// <summary>
+        /// Gets the filename extension of the image that can be retrieved with <see cref="GetImageContent"/>
+        /// </summary>
+        public string FileExtension
+        {
+            get
+            {
+                if (IsPng) return "png";
+                if (IsJpeg) return "jpg";
+                if (IsDds) return "dds";
+                if (IsWebp) return "webp";
+                return "raw";
+            }
+        }
+
         #endregion
 
         #region API

src/SharpGLTF.Core/Schema2/gltf.Node.cs

@@ -259,7 +259,7 @@ namespace SharpGLTF.Schema2
             set
             {
                 _weights.Clear();
-                _weights.AddRange(value.Select(item => (Double)item));
+                if (value != null) _weights.AddRange(value.Select(item => (Double)item));
             }
         }
 

src/SharpGLTF.Toolkit/Schema2/MeshExtensions.cs

@@ -333,7 +333,8 @@ namespace SharpGLTF.Schema2
 
             for (int i = 0; i < primitive.MorphTargetsCount; ++i)
             {
-                _CopyTo(primitive.GetMorphTargetAccessors(i), columns.AddMorphTarget());
+                var morphTarget = primitive.GetMorphTargetAccessors(i);
+                _CopyTo(morphTarget, columns.AddMorphTarget());
             }
 
             return columns;

tests/SharpGLTF.Tests/Schema2/LoadAndSave/LoadSampleTests.cs

@@ -238,7 +238,7 @@ namespace SharpGLTF.Schema2.LoadAndSave
             model.AttachToCurrentTest(path + ".glb");
 
             var triangles = model.DefaultScene
-                .Triangulate<Geometry.VertexTypes.VertexPosition, Geometry.VertexTypes.VertexEmpty>(null, 0)
+                .Triangulate<Geometry.VertexTypes.VertexPosition, Geometry.VertexTypes.VertexEmpty>()
                 .ToArray();            
 
             var anim = model.LogicalAnimations[0];
@@ -266,12 +266,49 @@ namespace SharpGLTF.Schema2.LoadAndSave
             var model = ModelRoot.Load(path);
             Assert.NotNull(model);
 
-            path = System.IO.Path.GetFileNameWithoutExtension(path);
-            model.AttachToCurrentTest(path + ".glb");
+            var anim = model.LogicalAnimations[0];
+            var node = model.LogicalNodes[0];
+
+            var acc_master = node.Mesh.Primitives[0].GetVertexAccessor("POSITION");
+            var acc_morph0 = node.Mesh.Primitives[0].GetMorphTargetAccessors(0)["POSITION"];
+            var acc_morph1 = node.Mesh.Primitives[0].GetMorphTargetAccessors(1)["POSITION"];
+
+            acc_morph0.AsVector3Array();
+
+            // pos_master
+
+            var pvrt = node.Mesh.Primitives[0].GetVertexColumns();
+
+            for (float t = 0; t < 5; t+=0.25f)
+            {
+                var nodexform = node.GetMeshWorldTransform(anim, t);
+
+                TestContext.WriteLine($"Animation at {t}");
+
+                if (t < anim.Duration)
+                {
+                    var mw = anim.GetMorphWeights(node, t);
+                    TestContext.WriteLine($"    Morph Weights: {mw[0]} {mw[1]}");
+                }
+
+                var msw = anim.GetSparseMorphWeights(node, t);
+                TestContext.WriteLine($"    Morph Sparse : {msw.Weight0} {msw.Weight1}");
+
+                var triangles = model.DefaultScene
+                    .Triangulate<Geometry.VertexTypes.VertexPosition, Geometry.VertexTypes.VertexEmpty>(anim, t)
+                    .ToList();
+
+                var vertices = triangles
+                    .SelectMany(item => new[] { item.Item1.Position, item.Item2.Position, item.Item3.Position })
+                    .Distinct()
+                    .ToList();
+
+                foreach (var v in vertices) TestContext.WriteLine($"{v}");
+
+                TestContext.WriteLine();
+            }
+
 
-            var triangles = model.DefaultScene
-                .Triangulate<Geometry.VertexTypes.VertexPosition, Geometry.VertexTypes.VertexEmpty>(null, 0)
-                .ToArray();
         }
     }
 }