diff --git a/Assets/VRM/Runtime/IO/VrmUtility.cs b/Assets/VRM/Runtime/IO/VrmUtility.cs
index 0a5ec9979..431ca1d1f 100644
--- a/Assets/VRM/Runtime/IO/VrmUtility.cs
+++ b/Assets/VRM/Runtime/IO/VrmUtility.cs
@@ -27,7 +27,12 @@ namespace VRM
                 try
                 {
                     var vrm = new VRMData(data);
-                    using (var loader = new VRMImporterContext(vrm, materialGenerator: materialGeneratorCallback(vrm.VrmExtension)))
+                    IMaterialDescriptorGenerator materialGen = default;
+                    if (materialGeneratorCallback != null)
+                    {
+                        materialGen = materialGeneratorCallback(vrm.VrmExtension);
+                    }
+                    using (var loader = new VRMImporterContext(vrm, materialGenerator: materialGen))
                     {
                         if (metaCallback != null)
                         {
diff --git a/Assets/VRM_Samples/RuntimeExporterSample/VRMRuntimeExporter.cs b/Assets/VRM_Samples/RuntimeExporterSample/VRMRuntimeExporter.cs
index 50c6fce21..0c39e342c 100644
--- a/Assets/VRM_Samples/RuntimeExporterSample/VRMRuntimeExporter.cs
+++ b/Assets/VRM_Samples/RuntimeExporterSample/VRMRuntimeExporter.cs
@@ -49,25 +49,11 @@ namespace VRM.RuntimeExporterSample
                 return;
             }
 
-            // GLB形式でJSONを取得しParseします
-            var data = new GlbFileParser(path).Parse();
-            // VRM extension を parse します
-            var vrm = new VRMData(data);
-            using (var context = new VRMImporterContext(vrm))
-            {
+            var loaded = await VrmUtility.LoadAsync(path);
 
-                // metaを取得(todo: thumbnailテクスチャのロード)
-                var meta = await context.ReadMetaAsync();
-                Debug.LogFormat("meta: title:{0}", meta.Title);
-
-                // ParseしたJSONをシーンオブジェクトに変換していく
-                var loaded = await context.LoadAsync();
-
-                loaded.ShowMeshes();
-                loaded.EnableUpdateWhenOffscreen();
-
-                OnLoaded(loaded.gameObject);
-            }
+            loaded.ShowMeshes();
+            loaded.EnableUpdateWhenOffscreen();
+            OnLoaded(loaded.gameObject);
         }
 
         void OnLoaded(GameObject go)