glTF exporter: add general material hook for unlit materials

io_scene_gltf2/__init__.py

@@ -4,7 +4,7 @@
 bl_info = {
     'name': 'glTF 2.0 format',
     'author': 'Julien Duroure, Scurest, Norbert Nopper, Urs Hanselmann, Moritz Becher, Benjamin Schmithüsen, Jim Eckerlein, and many external contributors',
-    "version": (3, 2, 31),
+    "version": (3, 2, 32),
     'blender': (3, 1, 0),
     'location': 'File > Import-Export',
     'description': 'Import-Export as glTF 2.0',

io_scene_gltf2/blender/exp/gltf2_blender_gather_materials.py

@@ -41,6 +41,7 @@ def gather_material(blender_material, active_uvmap_index, export_settings):
 
     mat_unlit = __gather_material_unlit(blender_material, active_uvmap_index, export_settings)
     if mat_unlit is not None:
+        export_user_extensions('gather_material_hook', export_settings, mat_unlit, blender_material)
         return mat_unlit
 
     orm_texture = __gather_orm_texture(blender_material, export_settings)