Custom root bone name setting

src/addons/send2ue/core/io/fbx_b3.py

@@ -348,7 +348,10 @@ def fbx_data_object_elements(root, ob_obj, scene_data):
             obj_type = b"Camera"
 
         if ob_obj.type == 'ARMATURE':
-            if bpy.context.scene.send2ue.export_object_name_as_root:
+            if bpy.context.scene.send2ue.export_custom_root_name:
+                # if the user has provided a custom name for a root bone, use this directly
+                ob_obj.name = bpy.context.scene.send2ue.export_custom_root_name
+            elif bpy.context.scene.send2ue.export_object_name_as_root:
                 # if the object is already named armature this forces the object name to root
                 if 'armature' == ob_obj.name.lower():
                     ob_obj.name = 'root'

src/addons/send2ue/core/io/fbx_b4.py

@@ -434,7 +434,10 @@ def fbx_data_object_elements(root, ob_obj, scene_data):
             obj_type = b"Camera"
 
         if ob_obj.type == 'ARMATURE':
-            if bpy.context.scene.send2ue.export_object_name_as_root:
+            if bpy.context.scene.send2ue.export_custom_root_name:
+                # if the user has provided a custom name for a root bone, use this directly
+                ob_obj.name = bpy.context.scene.send2ue.export_custom_root_name
+            elif bpy.context.scene.send2ue.export_object_name_as_root:
                 # if the object is already named armature this forces the object name to root
                 if 'armature' == ob_obj.name.lower():
                     ob_obj.name = 'root'

src/addons/send2ue/properties.py

@@ -286,6 +286,14 @@ class Send2UeSceneProperties(property_class):
                 "the first bone in the armature hierarchy is used as the root bone in unreal."
             )
         )
+        export_custom_root_name: bpy.props.StringProperty(
+            name="Custom root bone name",
+            default="",
+            description=(
+                "If specified, this adds a root bone by this name in Unreal. This overrides the "
+                "\"Export object name as root bone\" setting."
+            )
+        )
         export_custom_property_fcurves: bpy.props.BoolProperty(
             name="Export custom property fcurves",
             default=True,

src/addons/send2ue/ui/dialog.py

@@ -63,6 +63,7 @@ def draw_export_tab(self, layout):
         properties = bpy.context.scene.send2ue
         self.draw_property(properties, layout, 'use_object_origin')
         self.draw_property(properties, layout, 'export_object_name_as_root')
+        self.draw_property(properties, layout, 'export_custom_root_name', enabled=not properties.export_object_name_as_root)
 
         #  animation settings box
         self.draw_expanding_section(

tests/test_send2ue_cubes.py

@@ -23,6 +23,10 @@ def test_auto_stash_active_action_option(self):
     def test_export_object_name_as_root_option(self):
         pass
 
+    @unittest.skip
+    def test_custom_root_bone_name(self):
+        pass
+
     @unittest.skip
     def test_export_custom_property_fcurves_option(self):
         pass

tests/test_send2ue_mannequins.py

@@ -199,6 +199,19 @@ def test_export_object_name_as_root_option(self):
                 'frames': [2, 6, 11]
             }})
 
+    def test_custom_root_bone_name(self):
+        """
+        Tests custom root bone name option.
+        """
+        self.run_custom_root_bone_name_option_tests({
+            'SK_Mannequin_Female': {
+                'rig': 'female_root',
+                'animations': ['third_person_walk_01', 'third_person_run_01'],
+                'bones': ['spine_02', 'calf_l', 'lowerarm_r'],
+                'frames': [2, 6, 11],
+                'custom_name': 'my_test_root_bone',
+            }})
+
     def test_export_custom_property_fcurves_option(self):
         """
         Tests export custom property fcurves option.

tests/utils/base_test_case.py

@@ -691,7 +691,7 @@ def assert_curve(self, animation_name, curve_name, exists=True):
         else:
             self.assertFalse(result, f'Curve "{curve_name}" exists on animation "{animation_name}" when it should not!')
 
-    def assert_animation_hierarchy(self, rig_name, animation_name, bone_name, include_object=True):
+    def assert_animation_hierarchy(self, rig_name, animation_name, bone_name, include_object=True, custom_root_name=None):
         self.log(
             f'Checking the bone hierarchy of "{animation_name}" to see if "{bone_name}" has the same path '
             f'to the root bone...'
@@ -702,6 +702,9 @@ def assert_animation_hierarchy(self, rig_name, animation_name, bone_name, includ
         unreal_bone_path = self.unreal.get_bone_path_to_root(asset_path, bone_name)
         blender_bone_path = self.blender.get_bone_path_to_root(rig_name, bone_name, include_object)
 
+        if custom_root_name:
+            blender_bone_path.append(custom_root_name)
+
         self.assertEqual(
             collections.Counter(blender_bone_path),
             collections.Counter(unreal_bone_path),
@@ -1084,6 +1087,29 @@ def run_export_object_name_as_root_option_tests(self, objects_and_animations):
                     for frame in frames:
                         self.assert_animation_translation(rig_name, animation_name, bone_name, frame)
 
+    def run_custom_root_bone_name_option_tests(self, objects_and_animations):
+        self.blender.set_addon_property('scene', 'send2ue', 'export_all_actions', True)
+        self.blender.set_addon_property('scene', 'send2ue', 'import_animations', True)
+        # This option should be ignored as we're setting a custom name below.
+        self.blender.set_addon_property('scene', 'send2ue', 'export_object_name_as_root', True)
+
+        for object_name, data in objects_and_animations.items():
+            rig_name = data.get('rig')
+            animation_names = data.get('animations')
+            bone_names = data.get('bones')
+            frames = data.get('frames')
+            custom_root_bone_name = data.get('custom_name')
+            self.blender.set_addon_property('scene', 'send2ue', 'export_custom_root_name', custom_root_bone_name)
+            self.move_to_collection([object_name, rig_name], 'Export')
+            self.send2ue_operation()
+            self.assert_mesh_import(object_name)
+            # check that the animations are as expected
+            for animation_name in animation_names:
+                for bone_name in bone_names:
+                    self.assert_animation_hierarchy(rig_name, animation_name, bone_name, include_object=False, custom_root_name=custom_root_bone_name)
+                    for frame in frames:
+                        self.assert_animation_translation(rig_name, animation_name, bone_name, frame)
+
     def run_export_custom_property_fcurves_option_tests(self, objects_and_animations):
         self.blender.set_addon_property('scene', 'send2ue', 'export_all_actions', True)
         self.blender.set_addon_property('scene', 'send2ue', 'import_animations', True)
@@ -1168,6 +1194,9 @@ def test_export_object_name_as_root_option(self):
         """
         raise NotImplementedError('This test case must be implemented or skipped')
 
+    def test_custom_root_bone_name(self):
+        raise NotImplementedError('This test case must be implemented or skipped')
+
     def test_export_custom_property_fcurves_option(self):
         """
         Tests export custom property fcurves option.
@@ -1235,6 +1264,10 @@ def test_auto_stash_active_action_option(self):
     def test_export_object_name_as_root_option(self):
         pass
 
+    @unittest.skip
+    def test_custom_root_bone_name(self):
+        pass
+
     @unittest.skip
     def test_use_object_origin_option(self):
         pass