glTF importer/exporter: Manage some official Khronos Extensions about Materials

    KHR_materials_ior
    KHR_materials_sheen
    KHR_materials_specular
    KHR_materials_transmission
    KHR_materials_variants
    KHR_materials_emissive_strength
    KHR_materials_volume

Documentation update is still in progress

3 files changed, 39 insertions, 1 deletions

diff --git a/io_scene_gltf2/io/com/gltf2_io_constants.py b/io_scene_gltf2/io/com/gltf2_io_constants.py
index 19ead516..175804a3 100755
--- a/io_scene_gltf2/io/com/gltf2_io_constants.py
+++ b/io_scene_gltf2/io/com/gltf2_io_constants.py
@@ -145,3 +145,5 @@ GLTF_DATA_TYPE_VEC4 = "VEC4"
 GLTF_DATA_TYPE_MAT2 = "MAT2"
 GLTF_DATA_TYPE_MAT3 = "MAT3"
 GLTF_DATA_TYPE_MAT4 = "MAT4"
+
+GLTF_IOR = 1.5
\ No newline at end of file
diff --git a/io_scene_gltf2/io/com/gltf2_io_variants.py b/io_scene_gltf2/io/com/gltf2_io_variants.py
new file mode 100644
index 00000000..3824fee4
--- /dev/null
+++ b/io_scene_gltf2/io/com/gltf2_io_variants.py
@@ -0,0 +1,29 @@
+# SPDX-License-Identifier: Apache-2.0
+# Copyright 2018-2022 The glTF-Blender-IO authors.
+
+from io_scene_gltf2.io.com.gltf2_io import from_dict, from_union, from_none, from_float, from_str, from_list
+from io_scene_gltf2.io.com.gltf2_io import to_float, to_class
+
+class Variant:
+    """defines variant for use with glTF 2.0."""
+    def __init__(self, name, extensions, extras):
+        self.name = name
+        self.extensions = extensions
+        self.extras = extras
+
+    @staticmethod
+    def from_dict(obj):
+        assert isinstance(obj, dict)
+        name = from_union([from_str, from_none], obj.get("name"))
+        extensions = from_union([lambda x: from_dict(lambda x: from_dict(lambda x: x, x), x), from_none],
+                                obj.get("extensions"))
+        extras = obj.get("extras")
+        return Variant(name, extensions, extras)
+
+    def to_dict(self):
+        result = {}
+        result["name"] = from_union([from_str, from_none], self.name)
+        result["extensions"] = from_union([lambda x: from_dict(lambda x: from_dict(lambda x: x, x), x), from_none],
+                                          self.extensions)
+        result["extras"] = self.extras
+        return result
diff --git a/io_scene_gltf2/io/imp/gltf2_io_gltf.py b/io_scene_gltf2/io/imp/gltf2_io_gltf.py
index 9f096e69..75ce7265 100755
--- a/io_scene_gltf2/io/imp/gltf2_io_gltf.py
+++ b/io_scene_gltf2/io/imp/gltf2_io_gltf.py
@@ -28,6 +28,7 @@ class glTFImporter():
         self.accessor_cache = {}
         self.decode_accessor_cache = {}
         self.import_user_extensions = import_settings['import_user_extensions']
+        self.variant_mapping = {} # Used to map between mgltf material idx and blender material, for Variants
 
         if 'loglevel' not in self.import_settings.keys():
             self.import_settings['loglevel'] = logging.ERROR
@@ -44,7 +45,13 @@ class glTFImporter():
             'KHR_texture_transform',
             'KHR_materials_clearcoat',
             'KHR_mesh_quantization',
-            'KHR_draco_mesh_compression'
+            'KHR_draco_mesh_compression',
+            'KHR_materials_variants',
+            'KHR_materials_emissive_strength',
+            'KHR_materials_transmission',
+            'KHR_materials_specular',
+            'KHR_materials_sheen',
+            'KHR_materials_ior'
         ]
 
         # Add extensions required supported by custom import extensions