diff --git a/src/Raw2Gltf.cpp b/src/Raw2Gltf.cpp
index 919803e..40739d4 100644
--- a/src/Raw2Gltf.cpp
+++ b/src/Raw2Gltf.cpp
@@ -751,7 +751,8 @@ ModelData *Raw2Gltf(
 
             std::shared_ptr<MaterialData> mData = gltf->materials.hold(
                 new MaterialData(
-                    material.name, isTransparent, normalTexture, occlusionTexture, emissiveTexture,
+                    material.name, isTransparent, material.info->shadingModel,
+                    normalTexture, occlusionTexture, emissiveTexture,
                     emissiveFactor * emissiveIntensity, khrCmnUnlitMat, pbrMetRough));
             materialsByName[materialHash(material)] = mData;
         }
diff --git a/src/glTF/MaterialData.cpp b/src/glTF/MaterialData.cpp
index 3fbad6e..4a28d26 100644
--- a/src/glTF/MaterialData.cpp
+++ b/src/glTF/MaterialData.cpp
@@ -79,13 +79,14 @@ void to_json(json &j, const PBRMetallicRoughness &d)
 }
 
 MaterialData::MaterialData(
-    std::string name,  bool isTransparent, const TextureData *normalTexture,
-    const TextureData *occlusionTexture,
+    std::string name, bool isTransparent, const RawShadingModel shadingModel, 
+    const TextureData *normalTexture, const TextureData *occlusionTexture,
     const TextureData *emissiveTexture, const Vec3f & emissiveFactor,
     std::shared_ptr<KHRCmnUnlitMaterial> const khrCmnConstantMaterial,
     std::shared_ptr<PBRMetallicRoughness> const pbrMetallicRoughness)
     : Holdable(),
       name(std::move(name)),
+      shadingModel(shadingModel),
       isTransparent(isTransparent),
       normalTexture(Tex::ref(normalTexture)),
       occlusionTexture(Tex::ref(occlusionTexture)),
@@ -98,7 +99,13 @@ json MaterialData::serialize() const
 {
     json result = {
         { "name", name },
-        { "alphaMode", isTransparent ? "BLEND" : "OPAQUE" }
+        { "alphaMode", isTransparent ? "BLEND" : "OPAQUE" },
+        { "extras", {
+            { "fromFBX", {
+                { "shadingModel", Describe(shadingModel) },
+                { "isTruePBR", shadingModel == RAW_SHADING_MODEL_PBR_MET_ROUGH }
+            }}
+        }}
     };
 
     if (normalTexture != nullptr) {
diff --git a/src/glTF/MaterialData.h b/src/glTF/MaterialData.h
index 4ff4f1a..170c093 100644
--- a/src/glTF/MaterialData.h
+++ b/src/glTF/MaterialData.h
@@ -44,8 +44,8 @@ struct PBRMetallicRoughness
 struct MaterialData : Holdable
 {
     MaterialData(
-        std::string name, bool isTransparent, const TextureData *normalTexture,
-        const TextureData *occlusionTexture,
+        std::string name, bool isTransparent, RawShadingModel shadingModel,
+        const TextureData *normalTexture, const TextureData *occlusionTexture,
         const TextureData *emissiveTexture, const Vec3f &emissiveFactor,
         std::shared_ptr<KHRCmnUnlitMaterial> const khrCmnConstantMaterial,
         std::shared_ptr<PBRMetallicRoughness> const pbrMetallicRoughness);
@@ -53,6 +53,7 @@ struct MaterialData : Holdable
     json serialize() const override;
 
     const std::string                name;
+    const RawShadingModel            shadingModel;
     const bool                       isTransparent;
     const std::unique_ptr<const Tex> normalTexture;
     const std::unique_ptr<const Tex> occlusionTexture;