scripts-blender/addons/asset_pipeline_2/transfer_data/transfer_core.py

@@ -104,7 +104,6 @@ def apply_transfer_data(context: bpy.types.Context, transfer_data_map) -> None:
             if transfer_info.type == constants.VERTEX_GROUP_KEY:
                 print(f"Transfering Data {constants.VERTEX_GROUP_KEY}: {name}")
                 transfer_functions.transfer_vertex_group(
-                    context=context,
                     vertex_group_name=transfer_info.name,
                     target_obj=target_obj,
                     source_obj=source_obj,

scripts-blender/addons/asset_pipeline_2/transfer_data/transfer_functions.py

@@ -30,32 +30,56 @@ def init_vertex_groups(scene, obj):
 
 
 def transfer_vertex_group(
-    context,
     vertex_group_name: str,
     target_obj: bpy.types.Object,
     source_obj: bpy.types.Object,
 ):
+    # Adapted from https://stackoverflow.com/questions/40969164/how-to-add-vertex-groups-from-one-object-to-another-without-replacing-them
     if target_obj == source_obj:
         return
 
+    source_data = source_obj.data
+    target_data = target_obj.data
+
+    # sanity check: do source and target have the same amount of verts?
+    if len(source_data.vertices) != len(target_data.vertices):
+        print(
+            'ERROR: objects {} and {} have different vertex counts.'.format(
+                source_obj.name, target_obj.name
+            )
+        )
+        return
+
+    data = {}
+    for v in source_data.vertices:
+        vg = v.groups
+        vertex_index = v.index
+        if len(vg) > 0:
+            vgroup_collect = []
+            for i in range(0, len(vg)):
+                vgroup_collect.append((vg[i].group, vg[i].weight))
+            data[vertex_index] = vgroup_collect
+
+    # check if group already exists...
     if target_obj.vertex_groups.get(vertex_group_name):
         target_obj.vertex_groups.remove(target_obj.vertex_groups.get(vertex_group_name))
 
-    source_obj.vertex_groups.active = source_obj.vertex_groups[vertex_group_name]
-    # TODO Debug crashing / use context.temp_override(object=obj) style
-    override = context.copy()
-    override["selected_editable_objects"] = [target_obj, source_obj]
-    override["active_object"] = source_obj
-    override["object"] = source_obj
-    with context.temp_override(**override):
-        bpy.ops.object.data_transfer(
-            data_type="VGROUP_WEIGHTS",
-            use_create=True,
-            vert_mapping='POLYINTERP_NEAREST',
-            layers_select_src="ACTIVE",
-            layers_select_dst="NAME",
-            mix_mode="REPLACE",
-        )
+    # then add it
+    target_obj.vertex_groups.new(name=vertex_group_name)
+
+    # write weights
+    for v in target_data.vertices:
+        for vi_source, vgroupIndex_weight in data.items():
+            if v.index == vi_source:
+                for i in range(0, len(vgroupIndex_weight)):
+                    group = target_obj.vertex_groups
+                    for vgs in range(0, len(group)):
+                        if group[vgs].name == vertex_group_name:
+                            group[vgs].add(
+                                (v.index,),
+                                vgroupIndex_weight[i][1],
+                                "REPLACE",
+                            )
 
 
 # VERTEX COLORS