support KHR_materials_clearcoat during import

code/AssetLib/glTF2/glTF2Asset.h

@@ -47,6 +47,7 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  *   KHR_materials_unlit full
  *   KHR_lights_punctual full
  *   KHR_materials_sheen full
+ *   KHR_materials_clearcoat full
  */
 #ifndef GLTF2ASSET_H_INC
 #define GLTF2ASSET_H_INC
@@ -730,6 +731,14 @@ struct MaterialSheen {
     void SetDefaults();
 };
 
+struct MaterialClearcoat {
+    float clearcoatFactor = 0.f;
+    float clearcoatRoughnessFactor = 0.f;
+    TextureInfo clearcoatTexture;
+    TextureInfo clearcoatRoughnessTexture;
+    NormalTextureInfo clearcoatNormalTexture;
+};
+
 //! The material appearance of a primitive.
 struct Material : public Object {
     //PBR metallic roughness properties
@@ -750,6 +759,9 @@ struct Material : public Object {
     //extension: KHR_materials_sheen
     Nullable<MaterialSheen> materialSheen;
 
+    //extension: KHR_materials_clearcoat
+    Nullable<MaterialClearcoat> materialClearcoat;
+
     //extension: KHR_materials_unlit
     bool unlit;
 
@@ -1069,6 +1081,7 @@ public:
         bool KHR_lights_punctual;
         bool KHR_texture_transform;
         bool KHR_materials_sheen;
+        bool KHR_materials_clearcoat;
     } extensionsUsed;
 
     //! Keeps info about the required extensions

code/AssetLib/glTF2/glTF2Asset.inl

@@ -1055,6 +1055,20 @@ inline void Material::Read(Value &material, Asset &r) {
             }
         }
 
+        if (r.extensionsUsed.KHR_materials_clearcoat) {
+            if (Value *curMaterialClearcoat = FindObject(*extensions, "KHR_materials_clearcoat")) {
+                MaterialClearcoat clearcoat;
+
+                ReadMember(*curMaterialClearcoat, "clearcoatFactor", clearcoat.clearcoatFactor);
+                ReadTextureProperty(r, *curMaterialClearcoat, "clearcoatTexture", clearcoat.clearcoatTexture);
+                ReadMember(*curMaterialClearcoat, "clearcoatRoughnessFactor", clearcoat.clearcoatRoughnessFactor);
+                ReadTextureProperty(r, *curMaterialClearcoat, "clearcoatRoughnessTexture", clearcoat.clearcoatRoughnessTexture);
+                ReadTextureProperty(r, *curMaterialClearcoat, "clearcoatNormalTexture", clearcoat.clearcoatNormalTexture);
+
+                this->materialClearcoat = Nullable<MaterialClearcoat>(clearcoat);
+            }
+        }
+
         unlit = nullptr != FindObject(*extensions, "KHR_materials_unlit");
     }
 }
@@ -1751,6 +1765,7 @@ inline void Asset::ReadExtensionsUsed(Document &doc) {
     CHECK_EXT(KHR_lights_punctual);
     CHECK_EXT(KHR_texture_transform);
     CHECK_EXT(KHR_materials_sheen);
+    CHECK_EXT(KHR_materials_clearcoat);
 
 #undef CHECK_EXT
 }

code/AssetLib/glTF2/glTF2Importer.cpp

@@ -290,6 +290,17 @@ static aiMaterial *ImportMaterial(std::vector<int> &embeddedTexIdxs, Asset &r, M
         SetMaterialTextureProperty(embeddedTexIdxs, r, sheen.sheenColorTexture, aimat, AI_MATKEY_GLTF_MATERIAL_SHEEN_COLOR_TEXTURE);
         SetMaterialTextureProperty(embeddedTexIdxs, r, sheen.sheenRoughnessTexture, aimat, AI_MATKEY_GLTF_MATERIAL_SHEEN_ROUGHNESS_TEXTURE);
     }
+    //KHR_materials_clearcoat
+    if (mat.materialClearcoat.isPresent) {
+        MaterialClearcoat &clearcoat = mat.materialClearcoat.value;
+
+        aimat->AddProperty(&mat.materialClearcoat.isPresent, 1, AI_MATKEY_GLTF_MATERIAL_CLEARCOAT);
+        aimat->AddProperty(&clearcoat.clearcoatFactor, 1, AI_MATKEY_GLTF_MATERIAL_CLEARCOAT_FACTOR);
+        aimat->AddProperty(&clearcoat.clearcoatRoughnessFactor, 1, AI_MATKEY_GLTF_MATERIAL_CLEARCOAT_ROUGHNESS_FACTOR);
+        SetMaterialTextureProperty(embeddedTexIdxs, r, clearcoat.clearcoatTexture, aimat, AI_MATKEY_GLTF_MATERIAL_CLEARCOAT_TEXTURE);
+        SetMaterialTextureProperty(embeddedTexIdxs, r, clearcoat.clearcoatRoughnessTexture, aimat, AI_MATKEY_GLTF_MATERIAL_CLEARCOAT_ROUGHNESS_TEXTURE);
+        SetMaterialTextureProperty(embeddedTexIdxs, r, clearcoat.clearcoatNormalTexture, aimat, AI_MATKEY_GLTF_MATERIAL_CLEARCOAT_NORMAL_TEXTURE);
+    }
 
     return aimat;
 }

include/assimp/pbrmaterial.h

@@ -65,6 +65,12 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 #define AI_MATKEY_GLTF_MATERIAL_SHEEN_ROUGHNESS_FACTOR "$mat.gltf.materialSheen.sheenRoughnessFactor", 0, 0
 #define AI_MATKEY_GLTF_MATERIAL_SHEEN_COLOR_TEXTURE aiTextureType_UNKNOWN, 1
 #define AI_MATKEY_GLTF_MATERIAL_SHEEN_ROUGHNESS_TEXTURE aiTextureType_UNKNOWN, 2
+#define AI_MATKEY_GLTF_MATERIAL_CLEARCOAT "$mat.gltf.materialClearcoat", 0, 0
+#define AI_MATKEY_GLTF_MATERIAL_CLEARCOAT_FACTOR "$mat.gltf.materialClearcoat.clearcoatFactor", 0, 0
+#define AI_MATKEY_GLTF_MATERIAL_CLEARCOAT_ROUGHNESS_FACTOR "$mat.gltf.materialClearcoat.clearcoatRoughnessFactor", 0, 0
+#define AI_MATKEY_GLTF_MATERIAL_CLEARCOAT_TEXTURE aiTextureType_UNKNOWN, 3
+#define AI_MATKEY_GLTF_MATERIAL_CLEARCOAT_ROUGHNESS_TEXTURE aiTextureType_UNKNOWN, 4
+#define AI_MATKEY_GLTF_MATERIAL_CLEARCOAT_NORMAL_TEXTURE aiTextureType_NORMALS, 1
 
 #define _AI_MATKEY_GLTF_TEXTURE_TEXCOORD_BASE "$tex.file.texCoord"
 #define _AI_MATKEY_GLTF_MAPPINGNAME_BASE "$tex.mappingname"