io_scene_fbx/export_fbx_bin.py

@@ -2548,19 +2548,22 @@ def fbx_data_from_scene(scene, depsgraph, settings):
         # There are 4 different cases for what we need to do with the original data of each Object:
         # 1) The original data can be used without changes.
         # 2) A copy of the original data needs to be made.
-        #  - If a mesh needs to be modified upon export, e.g. it needs triangulating.
+        #  - If an export option modifies the data, e.g. Triangulate Faces is enabled.
-        #  - If a mesh has Object-linked materials. This is to do with how materials are currently mapped to FBX.
+        #  - If the Object has Object-linked materials. This is because our current mapping of materials to FBX requires
-        # 3) A non-mesh needs to be converted to a mesh.
+        #    that multiple Objects sharing a single mesh must have the same materials.
+        # 3) The Object needs to be converted to a mesh.
+        #  - All mesh-like Objects that are not meshes need to be converted to a mesh in order to be exported.
         # 4) The Object needs to be evaluated and then converted to a mesh.
-        #  - Whenever use_mesh_modifiers is enabled and either there are modifiers to apply or the Object is not a mesh.
+        #  - Whenever use_mesh_modifiers is enabled and either there are modifiers to apply or the Object needs to be
+        #    converted to a mesh.
         # If multiple cases apply to an Object, then only the last applicable case is relevant.
-        do_copy = any(ms.link == 'OBJECT' for ms in ob.material_slots) or (ob.type == 'MESH' and settings.use_triangles)
+        do_copy = any(ms.link == 'OBJECT' for ms in ob.material_slots) or settings.use_triangles
         do_convert = ob.type in BLENDER_OTHER_OBJECT_TYPES
         do_evaluate = do_convert and settings.use_mesh_modifiers
 
         # If the Object is a mesh, and we're applying modifiers, check if there are actually any modifiers to apply.
-        # If there are then the mesh will need to be evaluated, and we may need to make some temporary changes before
+        # If there are then the mesh will need to be evaluated, and we may need to make some temporary changes to the
-        # evaluating the mesh.
+        # modifiers or scene before the mesh is evaluated.
         backup_pose_positions = []
         tmp_mods = []
         if ob.type == 'MESH' and settings.use_mesh_modifiers:
@@ -2608,8 +2611,8 @@ def fbx_data_from_scene(scene, depsgraph, settings):
             tmp_me = bpy.data.meshes.new_from_object(
                 ob_to_convert, preserve_all_data_layers=True, depsgraph=depsgraph)
 
-            # Usually the materials of the evaluated object will be the same, but modifiers, such as Geometry
+            # Usually the materials of the evaluated object will be the same, but modifiers, such as Geometry Nodes,
-            # Nodes, can change the materials.
+            # can change the materials.
             orig_mats = tuple(slot.material for slot in ob.material_slots)
             eval_mats = tuple(slot.material.original if slot.material else None
                               for slot in ob_to_convert.material_slots)
@@ -2619,8 +2622,7 @@ def fbx_data_from_scene(scene, depsgraph, settings):
         elif do_convert:
             tmp_me = bpy.data.meshes.new_from_object(ob, preserve_all_data_layers=True, depsgraph=depsgraph)
         elif do_copy:
-            # bpy.data.meshes.new_from_object always removes shape keys (see #104714), so create a direct copy of the
+            # bpy.data.meshes.new_from_object removes shape keys (see #104714), so create a copy of the mesh instead.
-            # mesh instead.
             tmp_me = ob.data.copy()
         else:
             tmp_me = None