fix: vrm 1.0 bone child object translation importing

src/io_scene_vrm/importer/abstract_base_vrm_importer.py

@@ -13,6 +13,7 @@
 import struct
 import tempfile
 from abc import ABC, abstractmethod
+from collections.abc import Iterator
 from pathlib import Path
 from typing import Optional
 
@@ -144,6 +145,42 @@ def load_bone_child_object_world_matrices(self, armature: Object) -> None:
                     obj.name
                 ].copy()
 
+    @staticmethod
+    @contextlib.contextmanager
+    def save_bone_child_object_transforms(
+        context: Context, armature: Object
+    ) -> Iterator[Armature]:
+        if not isinstance(armature.data, Armature):
+            message = f"{type(armature.data)} is not an Armature"
+            raise TypeError(message)
+
+        # 編集前のボーンの子オブジェクトのワールド行列を保存
+        context.view_layer.update()
+        bone_child_object_world_matrices: dict[str, Matrix] = {}
+        for obj in context.blend_data.objects:
+            if (
+                obj.parent_type == "BONE"
+                and obj.parent == armature
+                and obj.parent_bone in armature.data.bones
+            ):
+                bone_child_object_world_matrices[obj.name] = obj.matrix_world.copy()
+
+        try:
+            with save_workspace(context, armature, mode="EDIT"):
+                yield armature.data
+        finally:
+            # 編集前のボーンの子オブジェクトのワールド行列を復元
+            context.view_layer.update()
+            for name, matrix_world in bone_child_object_world_matrices.items():
+                restore_obj = context.blend_data.objects.get(name)
+                if (
+                    restore_obj
+                    and restore_obj.parent_type == "BONE"
+                    and restore_obj.parent == armature
+                    and restore_obj.parent_bone in armature.data.bones
+                ):
+                    restore_obj.matrix_world = matrix_world.copy()
+
     def use_fake_user_for_thumbnail(self) -> None:
         # サムネイルはVRMの仕様ではimageのインデックスとあるが、UniVRMの実装ではtexture
         # のインデックスになっている

src/io_scene_vrm/importer/vrm1/vrm_importer.py

@@ -452,11 +452,9 @@ def setup_vrm1_humanoid_bones(self) -> None:
                 # Missing required bones
                 return
 
-        previous_active = self.context.view_layer.objects.active
-        previous_cursor_matrix = self.context.scene.cursor.matrix
-        try:
-            self.context.view_layer.objects.active = armature
-
+        with self.save_bone_child_object_transforms(
+            self.context, armature
+        ) as armature_data:
             bone_name_to_human_bone_name: dict[str, HumanBoneName] = {}
             for (
                 human_bone_name,
@@ -468,8 +466,6 @@ def setup_vrm1_humanoid_bones(self) -> None:
                     human_bone_name
                 )
 
-            bpy.ops.object.mode_set(mode="EDIT")
-
             # ボーンの子が複数ある場合
             # そのボーン名からテールを向ける先の子ボーン名を拾えるdictを作る
             bone_name_to_main_child_bone_name: dict[str, str] = {}
@@ -487,7 +483,7 @@ def setup_vrm1_humanoid_bones(self) -> None:
                 if human_bone_name in [HumanBoneName.RIGHT_EYE, HumanBoneName.LEFT_EYE]:
                     continue
 
-                bone = self.armature_data.edit_bones.get(bone_name)
+                bone = armature_data.edit_bones.get(bone_name)
                 if not bone:
                     continue
                 last_human_bone_name = human_bone_name
@@ -550,7 +546,7 @@ def setup_vrm1_humanoid_bones(self) -> None:
             # ヒューマンボーンとその先祖ボーンを得る
             human_bone_tree_bone_names: set[str] = set()
             for bone_name in bone_name_to_human_bone_name:
-                bone = self.armature_data.edit_bones.get(bone_name)
+                bone = armature_data.edit_bones.get(bone_name)
                 while bone:
                     human_bone_tree_bone_names.add(bone.name)
                     bone = bone.parent
@@ -613,7 +609,7 @@ def setup_vrm1_humanoid_bones(self) -> None:
             # その先祖ボーンを優先したいので、それらを深さ優先で先に処理し、
             # その後その他のボーンを深さ優先で処理する
             unsorted_bones = [
-                bone for bone in self.armature_data.edit_bones if not bone.parent
+                bone for bone in armature_data.edit_bones if not bone.parent
             ]
             while unsorted_bones:
                 bone = unsorted_bones.pop()
@@ -760,13 +756,11 @@ def setup_vrm1_humanoid_bones(self) -> None:
                     )
                 bone_name_to_axis_translation[bone.name] = axis_translation
 
-            connect_parent_tail_and_child_head_if_very_close_position(
-                self.armature_data
-            )
+            connect_parent_tail_and_child_head_if_very_close_position(armature_data)
 
             bpy.ops.object.mode_set(mode="OBJECT")
             for bone_name, axis_translation in bone_name_to_axis_translation.items():
-                data_bone = self.armature_data.bones.get(bone_name)
+                data_bone = armature_data.bones.get(bone_name)
                 if not data_bone:
                     continue
                 data_bone.vrm_addon_extension.axis_translation = (
@@ -793,16 +787,6 @@ def setup_vrm1_humanoid_bones(self) -> None:
                             ),
                         )
                         break
-        finally:
-            if (
-                self.context.view_layer.objects.active
-                and self.context.view_layer.objects.active.mode != "OBJECT"
-            ):
-                bpy.ops.object.mode_set(mode="OBJECT")
-            self.context.view_layer.objects.active = previous_active
-            self.context.scene.cursor.matrix = previous_cursor_matrix
-
-        self.load_bone_child_object_world_matrices(armature)
 
     def translate_object_axis(self, obj: Object, axis_translation: str) -> None:
         if axis_translation != BoneExtension.AXIS_TRANSLATION_AUTO_ID: