Add zero weight bone removal

functions/armature_modifying.py

@@ -0,0 +1,64 @@
+import bpy
+from ..core import common
+from bpy.types import Operator, Context, Mesh, Armature, EditBone, PoseBone
+from ..core.register import register_wrap
+from .translations import t
+
+@register_wrap
+class AvatarToolkit_RemoveZeroWeightBones(Operator):
+    bl_idname = "avatar_toolkit.remove_zero_weight_bones"
+    bl_label = t("Tools.remove_zero_weight_bones.label")
+    bl_description = t("Tools.remove_zero_weight_bones.desc")
+    bl_options = {'REGISTER', 'UNDO'}
+
+    threshold: bpy.props.FloatProperty(
+        default=0.01,
+        name=t("Tools.remove_zero_weight_bones.threshold.label"),
+        description=t("Tools.remove_zero_weight_bones.threshold.desc"),
+        min=0.0000001, 
+        max=0.9999999)
+
+    @classmethod
+    def poll(cls, context: Context) -> bool:
+        return common.get_selected_armature(context) is not None
+
+    def execute(self, context: Context) -> set[str]:
+        armature = common.get_selected_armature(context)
+        if not common.is_valid_armature(armature):
+            self.report({'ERROR'}, t("Tools.apply_transforms.invalid_armature"))
+            return {'CANCELLED'}
+
+        weighted_bones: list[str] = []
+
+
+        bpy.ops.object.mode_set(mode='OBJECT')
+        bpy.ops.object.select_all(action='DESELECT')
+
+        armature.select_set(True)
+        context.view_layer.objects.active = armature
+
+        meshes = common.get_all_meshes(context)
+        for mesh in meshes:
+            mesh_data: Mesh = mesh.data
+            for vertex in mesh_data.vertices:
+                for group in vertex.groups:
+                    if group.weight > self.threshold: 
+                        weighted_bones.append(mesh.vertex_groups[group.group].name) #add bone name to list of bones that are greater than the weight threshold
+        
+        bpy.ops.object.mode_set(mode='EDIT')
+        amature_data: Armature = armature.data
+        unweighted_bones: list[str] = []
+
+        #doing 2 loops to prevent modification of array during iteration
+        for bone in amature_data.edit_bones:
+            if bone.name not in weighted_bones:
+                unweighted_bones.append(bone.name) #add bones that arent in the list of bones that have weight into the list of bones that don't
+
+        for bone_name in unweighted_bones:
+            for edit_bone in amature_data.edit_bones[bone_name].children: 
+                edit_bone.use_connect = False #to fix randomly moving bones
+                edit_bone.parent = amature_data.edit_bones[bone_name].parent #to fix unparented bones.
+            amature_data.edit_bones.remove(amature_data.edit_bones[bone_name]) #delete list of unweighted bones from the armature
+
+        self.report({'INFO'}, t("Tools.remove_zero_weight_bones.success"))
+        return {'FINISHED'}