1 files changed, 35 insertions, 0 deletions
diff --git a/io_scene_gltf2/blender/exp/gltf2_blender_gather_materials_ior.py b/io_scene_gltf2/blender/exp/gltf2_blender_gather_materials_ior.py
new file mode 100644
index 00000000..fc219c01
--- /dev/null
+++ b/io_scene_gltf2/blender/exp/gltf2_blender_gather_materials_ior.py
@@ -0,0 +1,35 @@
+# SPDX-License-Identifier: Apache-2.0
+# Copyright 2018-2022 The glTF-Blender-IO authors.
+
+from io_scene_gltf2.io.com.gltf2_io_extensions import Extension
+from io_scene_gltf2.blender.exp import gltf2_blender_get
+from io_scene_gltf2.io.com.gltf2_io_constants import GLTF_IOR
+
+def export_ior(blender_material, extensions, export_settings):
+    ior_socket = gltf2_blender_get.get_socket(blender_material, 'IOR')
+
+    if not ior_socket:
+        return None
+
+    # We don't manage case where socket is linked, always check default value
+    if ior_socket.is_linked:
+        # TODOExt: add warning?
+        return None
+
+    if ior_socket.default_value == GLTF_IOR:
+        return None
+
+    # Export only if the following extensions are exported:
+    need_to_export_ior = [
+        'KHR_materials_transmission',
+        'KHR_materials_volume',
+        'KHR_materials_specular'
+    ]
+
+    if not any([e in extensions.keys() for e in need_to_export_ior]):
+        return None
+
+    ior_extension = {}
+    ior_extension['ior'] = ior_socket.default_value
+
+    return Extension('KHR_materials_ior', ior_extension, False)
+\ No newline at end of file