feat(merge groups): Update merge group handling

This update overhauls the merge group system to have a more intuitive userinterface similar
to how Blender handles textures, materials etc. with a dropdown menu to select any existing
merge group as well as buttons for creating new merge groups, deleting merge groups, selecting
the root merge group root as well as a helper button for selecting all merge group objects for
a given merge group. **This new way of handling merge groups is entirely backwards compatible
and any existing merge groups using the old string format will be converted to the new format
when the file is loaded!**

Close #79 resolve #172

Co-authored-by: Kristian <[email protected]>

addon/i3dio/__init__.py

@@ -43,7 +43,6 @@
 
 
 def register():
-
     try:
         import lxml
     except ImportError as e:
@@ -77,10 +76,8 @@ def register():
     ui.user_attributes.register()
     ui.mesh.register()
     ui.light.register()
-
     bpy.types.TOPBAR_MT_file_export.append(ui.exporter.menu_func_export)
 
-
 def unregister():
     bpy.types.TOPBAR_MT_file_export.remove(ui.exporter.menu_func_export)
     ui.exporter.unregister()

addon/i3dio/exporter.py

@@ -18,6 +18,7 @@
 from .i3d import I3D
 from .node_classes.node import SceneGraphNode
 from .node_classes.skinned_mesh import SkinnedMeshRootNode
+from .node_classes.merge_group import MergeGroup
 
 logger = logging.getLogger(__name__)
 logger.debug(f"Loading: {__name__}")
@@ -181,9 +182,11 @@ def _add_object_to_i3d(i3d: I3D, obj: BlenderObject, parent: SceneGraphNode = No
                         break
 
             if node is None:
-                if 'MERGE_GROUPS' in i3d.settings['features_to_export'] and obj.i3d_merge_group.group_id != "":
-                    # Currently the check for a mergegroup relies solely on whether or not a name is set for it
-                    node = i3d.add_merge_group_node(obj, _parent)
+                if 'MERGE_GROUPS' in i3d.settings['features_to_export'] and obj.i3d_merge_group_index != -1:
+                    blender_merge_group = bpy.context.scene.i3dio_merge_groups[obj.i3d_merge_group_index]
+                    if obj.i3d_merge_group_index not in i3d.merge_groups:
+                        i3d.merge_groups[obj.i3d_merge_group_index] = MergeGroup(xml_i3d.merge_group_prefix + blender_merge_group.name)
+                    node = i3d.add_merge_group_node(obj, _parent, blender_merge_group.root is obj)
                 else:
                     # Default to a regular shape node
                     node = i3d.add_shape_node(obj, _parent)

addon/i3dio/i3d.py

@@ -41,7 +41,7 @@ def __init__(self, name: str, i3d_file_path: str, conversion_matrix: mathutils.M
         self.shapes: Dict[Union[str, int], IndexedTriangleSet] = {}
         self.materials: Dict[Union[str, int], Material] = {}
         self.files: Dict[Union[str, int], File] = {}
-        self.merge_groups: Dict[str, MergeGroup] = {}
+        self.merge_groups: Dict[int, MergeGroup] = {}
         self.skinned_meshes: Dict[str, SkinnedMeshRootNode] = {}
 
         self.i3d_mapping: List[SceneGraphNode] = []
@@ -72,34 +72,24 @@ def add_shape_node(self, mesh_object: bpy.types.Object, parent: SceneGraphNode =
         """Add a blender object with a data type of MESH to the scenegraph as a Shape node"""
         return self._add_node(ShapeNode, mesh_object, parent)
 
-    def add_merge_group_node(self, merge_group_object: bpy.types.Object, parent: SceneGraphNode = None) \
+    def add_merge_group_node(self, merge_group_object: bpy.types.Object, parent: SceneGraphNode = None, is_root: bool = False) \
             -> [SceneGraphNode, None]:
         self.logger.debug("Adding merge group node")
-        merge_group_id = merge_group_object.i3d_merge_group.group_id
-        merge_group_name = xml_i3d.merge_group_prefix + merge_group_id
-        node_to_return: [MergeGroupRoot or MergeGroupRoot] = None
-        if merge_group_name not in self.merge_groups:
-            self.logger.debug("New merge group")
-            merge_group = self.merge_groups[merge_group_name] = MergeGroup(merge_group_name)
-            if merge_group_object.i3d_merge_group.is_root:
+        merge_group = self.merge_groups[merge_group_object.i3d_merge_group_index]
+
+        node_to_return: [MergeGroupRoot or MergeGroupChild] = None
+
+        if is_root:
+            if merge_group.root_node is not None:
+                    self.logger.warning(f"Merge group '{merge_group.name}' already has a root node! "
+                                        f"The object '{merge_group_object.name}' will be ignored for export")
+            else:
                 node_to_return = self._add_node(MergeGroupRoot, merge_group_object, parent)
                 merge_group.set_root(node_to_return)
-            else:
-                node_to_return = self._add_node(MergeGroupChild, merge_group_object, parent)
-                merge_group.add_child(node_to_return)
         else:
-            self.logger.debug("Merge group already exists")
-            merge_group = self.merge_groups[merge_group_name]
-            if merge_group_object.i3d_merge_group.is_root:
-                if merge_group.root_node is not None:
-                    self.logger.warning(f"Merge group '{merge_group_id}' already has a root node! "
-                                        f"The object '{merge_group_object.name}' will be ignored for export")
-                else:
-                    node_to_return = self._add_node(MergeGroupRoot, merge_group_object, parent)
-                    merge_group.set_root(node_to_return)
-            else:
-                node_to_return = self._add_node(MergeGroupChild, merge_group_object, parent)
-                merge_group.add_child(node_to_return)
+            node_to_return = self._add_node(MergeGroupChild, merge_group_object, parent)
+            merge_group.add_child(node_to_return)
+
         return node_to_return
 
     def add_bone(self, bone_object: bpy.types.Bone, parent: Union[SkinnedMeshBoneNode, SkinnedMeshRootNode]) \

addon/i3dio/node_classes/merge_group.py

@@ -21,7 +21,7 @@ class MergeGroupRoot(ShapeNode):
 
     def __init__(self, id_: int, merge_group_object: [bpy.types.Object, None], i3d: I3D,
                  parent: [SceneGraphNode or None] = None):
-        self.merge_group_name = xml_i3d.merge_group_prefix + merge_group_object.i3d_merge_group.group_id
+        self.merge_group_name = i3d.merge_groups[merge_group_object.i3d_merge_group_index].name
         self.skin_bind_ids = f"{id_:d} "
         super().__init__(id_=id_, mesh_object=merge_group_object, i3d=i3d, parent=parent)
 

addon/i3dio/ui/exporter.py

@@ -31,7 +31,6 @@ def register(cls):
     classes.append(cls)
     return cls
 
-
 @register
 class I3DExportUIProperties(bpy.types.PropertyGroup):
     selection: EnumProperty(
@@ -168,7 +167,6 @@ class I3DExportUIProperties(bpy.types.PropertyGroup):
         default='CLEAN'
     )
 
-
 @register
 @orientation_helper(axis_forward='-Z', axis_up='Y')
 class I3D_IO_OT_export(Operator, ExportHelper):

addon/i3dio/ui/object.py

@@ -3,6 +3,8 @@
     Panel
 )
 
+from bpy.app.handlers import (persistent, save_pre, load_post)
+
 from bpy.props import (
     StringProperty,
     BoolProperty,
@@ -557,20 +559,40 @@ def draw(self, context):
             obj.i3d_attributes.property_unset('weather_required_mask')
             obj.i3d_attributes.property_unset('weather_prevent_mask')
 
-
 @register
-class I3DMergeGroupObjectData(bpy.types.PropertyGroup):
-    is_root: BoolProperty(
-        name="Root of merge group",
-        description="Check if this object is gonna be the root object holding the mesh",
-        default=False
-    )
-
-    group_id: StringProperty(name='Merge Group',
-                             description='The merge group this object belongs to',
-                             default=''
-                             )
+class I3DMergeGroupMemberObject(bpy.types.PropertyGroup):
+    object: PointerProperty(
+        name="Merge Group Member",
+        type=bpy.types.Object,
+		)
 
+@register
+class I3DMergeGroup(bpy.types.PropertyGroup):
+    def add_member(self, member_object):
+        self.members.add().object = member_object
+
+    def remove_member(self, member_object):
+        for idx,member in enumerate(self.members):
+            if member.object is member_object:
+                self.members.remove(idx)
+
+    name: StringProperty(
+        name='Merge Group Name',
+        description='The name of the merge group',
+        default='MergeGroup'
+    )
+
+    members: CollectionProperty(
+        name="Members",
+        description="Members of the merge group",
+        type=I3DMergeGroupMemberObject)
+
+    root: PointerProperty(
+        name="Merge Group Root Object",
+        description="The object acting as the root for the merge group",
+        type=bpy.types.Object,
+		)
+
 @register
 class I3D_IO_PT_merge_group_attributes(Panel):
     bl_space_type = 'PROPERTIES'
@@ -587,16 +609,162 @@ def draw(self, context):
         layout = self.layout
         layout.use_property_split = True
         layout.use_property_decorate = False
-        obj = bpy.context.active_object
+        obj = context.object
 
-        row = layout.row()
-        row.prop(obj.i3d_merge_group, 'is_root')
-        if obj.i3d_merge_group.group_id == '':  # Defaults to a default initialized placeholder
-            row.enabled = False
+        row = layout.row(align=True)
+        row.use_property_decorate = False
 
-        row = layout.row()
-        row.prop(obj.i3d_merge_group, 'group_id')
+        row.operator('i3dio.choose_merge_group', text="", icon='DOWNARROW_HLT')
+
+        col = row.column(align=True)
+        merge_group_index = obj.i3d_merge_group_index 
+        if merge_group_index == -1:
+            col.operator("i3dio.new_merge_group", text="New", icon="ADD")
+        else:
+            merge_group = context.scene.i3dio_merge_groups[merge_group_index]
+            col.prop(merge_group, "name", text="")
+            col = row.column(align=True)
+            col.operator('i3dio.select_merge_group_root', text="", icon="COLOR_RED")
+            col = row.column(align=True)
+            col.operator('i3dio.select_mg_objects', text="", icon='GROUP_VERTEX')
+            col = row.column(align=True)
+            col.operator('i3dio.new_merge_group', text="", icon='DUPLICATE')
+            col = row.column(align=True)
+            col.operator('i3dio.remove_merge_group', text="", icon='PANEL_CLOSE')
+
+
+@register
+class I3D_IO_OT_choose_merge_group(bpy.types.Operator):
+    bl_idname = "i3dio.choose_merge_group"
+    bl_label = "Choose Merge Group"
+    bl_description = "Choose a merge group to assign this object to"
+    bl_options = {'INTERNAL', 'UNDO'}
+    bl_property = "enum"
+
+    def get_enum_options(self, context):
+        merge_groups_item_list = sorted([(str(idx), mg.name, "") for idx,mg in enumerate(context.scene.i3dio_merge_groups)],key=lambda x: x[1])
+        return merge_groups_item_list
+
+    enum: EnumProperty(items=get_enum_options, name="Items")
+
+    def execute(self, context):
+        obj = context.object
+        selected_mg_index = int(self.enum)
+        if obj.i3d_merge_group_index != selected_mg_index:
+            context.scene.i3dio_merge_groups[obj.i3d_merge_group_index].remove_member(obj)
+            context.scene.i3dio_merge_groups[selected_mg_index].add_member(obj)
+            obj.i3d_merge_group_index = selected_mg_index
+            context.area.tag_redraw()
+        return {"FINISHED"}
+
+    def invoke(self, context, event):
+        context.window_manager.invoke_search_popup(self)
+        return {"RUNNING_MODAL"}
 
+@register
+class I3D_IO_OT_new_merge_group(bpy.types.Operator):
+    bl_idname = "i3dio.new_merge_group"
+    bl_label = "New Merge Group"
+    bl_description = "Create a new merge group"
+    bl_options = {'INTERNAL', 'UNDO'}
+
+    def execute(self, context):
+        MERGE_GROUP_DEFAULT_NAME = "MergeGroup"
+
+        obj = context.object
+        name = MERGE_GROUP_DEFAULT_NAME
+        count = 1
+        while context.scene.i3dio_merge_groups.find(name) != -1:
+            name = f"{MERGE_GROUP_DEFAULT_NAME}.{count:03d}"
+            count += 1
+        mg = context.scene.i3dio_merge_groups.add()
+        if obj.i3d_merge_group_index != -1:
+            context.scene.i3dio_merge_groups[obj.i3d_merge_group_index].remove_member(obj)
+        mg.name = name
+        mg.root = obj
+        mg.add_member(obj)
+        obj.i3d_merge_group_index = len(context.scene.i3dio_merge_groups) - 1
+        return {'FINISHED'}
+
+
+@register
+class I3D_IO_OT_remove_merge_group(bpy.types.Operator):
+    bl_idname = "i3dio.remove_merge_group"
+    bl_label = "Remove From Merge Group"
+    bl_description = "Remove this object from it's current merge group"
+    bl_options = {'INTERNAL', 'UNDO'}
+
+    def execute(self, context):
+        mg_index = context.object.i3d_merge_group_index
+        for member in context.scene.i3dio_merge_groups[mg_index].members:
+            member.object.i3d_merge_group_index = -1
+        context.scene.i3dio_merge_groups.remove(mg_index)
+        for mg in context.scene.i3dio_merge_groups[mg_index::]:
+            for member in mg.members:
+                member.object.i3d_merge_group_index -= 1
+        return {'FINISHED'}
+
+@register
+class I3D_IO_OT_select_merge_group_root(bpy.types.Operator):
+    bl_idname = "i3dio.select_merge_group_root"
+    bl_label = "Select Merge Group Root"
+    bl_description = "When greyed out it means that the current object is the merge group root"
+    bl_options = {'INTERNAL'}
+
+    @classmethod
+    def poll(cls, context):
+        return context.scene.i3dio_merge_groups[context.object.i3d_merge_group_index].root is not context.object
+
+    def execute(self, context):
+        context.scene.i3dio_merge_groups[context.object.i3d_merge_group_index].root = context.object
+        return {'FINISHED'}
+
+@register
+class I3D_IO_OT_select_mg_objects(bpy.types.Operator):
+    bl_idname = "i3dio.select_mg_objects"
+    bl_label = "Select Objects in MG"
+    bl_description = "Select all objects in the same merge group"
+    bl_options = {'UNDO'}
+
+    @classmethod
+    def poll(cls, context):
+        return context.object.i3d_merge_group_index != -1
+
+    def execute(self, context):
+        for member in context.scene.i3dio_merge_groups[context.object.i3d_merge_group_index].members:
+            if member.object is not None:
+                member.object.select_set(True)
+            else:
+                print("Deleted Member Object")
+        return {'FINISHED'}
+
+@persistent
+def prune_merge_groups(dummy):
+    for scene in bpy.data.scenes:
+        for mg in scene.i3dio_merge_groups:
+            for idx, member in reversed(list(enumerate(mg.members))):
+                if member.object is None:
+                    mg.members.remove(idx)
+
+@persistent
+def handle_old_merge_groups(dummy):
+    for scene in bpy.data.scenes:
+        for obj in scene.objects:
+            if (old_mg := obj.get('i3d_merge_group')) != None:
+                group_id = old_mg.get('group_id')
+                is_root = old_mg.get('is_root')
+                if group_id != None and group_id != "":
+                    if (mg_idx := scene.i3dio_merge_groups.find(group_id)) != -1:
+                        mg = scene.i3dio_merge_groups[mg_idx]
+                        obj.i3d_merge_group_index = mg_idx
+                    else:
+                        mg = scene.i3dio_merge_groups.add()
+                        mg.name = group_id
+                        obj.i3d_merge_group_index = len(scene.i3dio_merge_groups) - 1
+                    mg.add_member(obj)
+                    if is_root != None and is_root == 1:
+                        mg.root = obj
+                del obj['i3d_merge_group']
 
 @register
 class I3D_IO_PT_joint_attributes(Panel):
@@ -679,18 +847,22 @@ def draw(self, context):
         row = layout.row()
         row.prop(obj.i3d_mapping, 'mapping_name')
 
-
 def register():
     for cls in classes:
         bpy.utils.register_class(cls)
     bpy.types.Object.i3d_attributes = PointerProperty(type=I3DNodeObjectAttributes)
-    bpy.types.Object.i3d_merge_group = PointerProperty(type=I3DMergeGroupObjectData)
+    bpy.types.Object.i3d_merge_group_index = IntProperty(default = -1)
     bpy.types.Object.i3d_mapping = PointerProperty(type=I3DMappingData)
-
+    bpy.types.Scene.i3dio_merge_groups = CollectionProperty(type=I3DMergeGroup)
+    save_pre.append(prune_merge_groups)
+    load_post.append(handle_old_merge_groups)
 
 def unregister():
+    load_post.remove(handle_old_merge_groups)
+    save_pre.remove(prune_merge_groups)
+    del bpy.types.Scene.i3dio_merge_groups
     del bpy.types.Object.i3d_mapping
-    del bpy.types.Object.i3d_merge_group
+    del bpy.types.Object.i3d_merge_group_index
     del bpy.types.Object.i3d_attributes
 
     for cls in classes: