diff --git a/src/ObjCommon/XModel/Gltf/JsonGltf.h b/src/ObjCommon/XModel/Gltf/JsonGltf.h
index f7b18b12..2f3a15d4 100644
--- a/src/ObjCommon/XModel/Gltf/JsonGltf.h
+++ b/src/ObjCommon/XModel/Gltf/JsonGltf.h
@@ -206,9 +206,10 @@ namespace gltf
     {
     public:
         std::optional<JsonTextureInfo> baseColorTexture;
+        std::optional<float> metallicFactor;
     };
 
-    NLOHMANN_DEFINE_TYPE_EXTENSION(JsonPbrMetallicRoughness, baseColorTexture);
+    NLOHMANN_DEFINE_TYPE_EXTENSION(JsonPbrMetallicRoughness, baseColorTexture, metallicFactor);
 
     class JsonNormalTextureInfo
     {
diff --git a/src/ObjWriting/XModel/Gltf/GltfWriter.cpp b/src/ObjWriting/XModel/Gltf/GltfWriter.cpp
index ed640ba9..3feeada7 100644
--- a/src/ObjWriting/XModel/Gltf/GltfWriter.cpp
+++ b/src/ObjWriting/XModel/Gltf/GltfWriter.cpp
@@ -127,7 +127,13 @@ namespace
                 material.name = modelMaterial.name;
 
                 if (!modelMaterial.colorMapName.empty())
-                    material.pbrMetallicRoughness.emplace().baseColorTexture.emplace().index = CreateTexture(gltf, modelMaterial.colorMapName);
+                {
+                    material.pbrMetallicRoughness.emplace();
+                    material.pbrMetallicRoughness->baseColorTexture.emplace();
+
+                    material.pbrMetallicRoughness->baseColorTexture->index = CreateTexture(gltf, modelMaterial.colorMapName);
+                    material.pbrMetallicRoughness->metallicFactor = 0.0f;
+                }
 
                 if (!modelMaterial.normalMapName.empty())
                     material.normalTexture.emplace().index = CreateTexture(gltf, modelMaterial.colorMapName);