fix primitive.material

Assets/VRM10/Runtime/IO/MeshAdapter.cs

@@ -316,7 +316,7 @@ namespace UniVRM10
                 var prim = new glTFPrimitives
                 {
                     mode = (int)mesh.Topology,
-                    material = materials.IndexOf(y.Material),
+                    material = y.Material,
                     indices = indicesAccessorIndex,
                     attributes = new glTFAttributes(),
                 };

Assets/VRM10/Runtime/IO/Vrm10Exporter.cs

@@ -162,12 +162,6 @@ namespace UniVRM10
                 Reserve(reserveBytes);
             }
 
-            // mesh
-            ExportMeshes(model.MeshGroups, model.Materials, option);
-
-            // node
-            ExportNodes(model.Root, model.Nodes, model.MeshGroups, option);
-
             // material
             var materialExporter = new Vrm10MaterialExporter();
             foreach (Material material in model.Materials)
@@ -176,6 +170,12 @@ namespace UniVRM10
                 Storage.Gltf.materials.Add(glTFMaterial);
             }
 
+            // mesh
+            ExportMeshes(model.MeshGroups, model.Materials, option);
+
+            // node
+            ExportNodes(model.Root, model.Nodes, model.MeshGroups, option);
+
             var (vrm, vrmSpringBone, thumbnailTextureIndex) = ExportVrm(root, model, converter, metaObject);
 
             // Extension で Texture が増える場合があるので最後に呼ぶ