tweak_lattice.py

@@ -193,6 +193,47 @@ class TWEAKLAT_OT_Create(Operator):
         return {'FINISHED'}
 
 
+
+class TWEAKLAT_OT_Duplicate(Operator):
+    """Duplicate this Tweak Lattice set-up"""
+    bl_idname = "lattice.duplicate_tweak_setup"
+    bl_label = "Duplicate Tweak Lattice"
+    bl_options = {'REGISTER', 'UNDO', 'INTERNAL'}
+
+    def execute(self, context):
+        hook, lattice, root = get_tweak_setup(context.object)
+        bpy.ops.object.select_all(action='DESELECT')
+
+        affected_objects = get_objects_of_lattice(hook)
+
+        visibilities = {}
+        for ob in [hook, lattice, root]:
+            ob.hide_set(False)
+            visibilities[ob] = ob.hide_viewport
+            ob.hide_viewport = False
+            if not ob.visible_get():
+                self.report({'ERROR'}, f'Object "{ob.name}" could not be made visible, cancelling.')
+                return {'CANCELLED'}
+            ob.select_set(True)
+
+        context.view_layer.objects.active = hook
+
+        bpy.ops.object.duplicate()
+        new_hook, new_lattice, new_root = get_tweak_setup(context.object)
+
+        for key, value in new_hook.items():
+            if key.startswith("object_"):
+                del new_hook[key]
+
+        add_objects_to_lattice(new_hook, affected_objects)
+
+        # Restore visibilities
+        for ob, new_ob in zip((hook, lattice, root), (new_hook, new_lattice, new_root)):
+            ob.hide_viewport = new_ob.hide_viewport = visibilities[ob]
+
+        return {'FINISHED'}
+
+
 class TWEAKLAT_OT_Falloff(Operator):
     """Adjust falloff of the hook vertex group of a Tweak Lattice"""
     bl_idname = "lattice.tweak_lattice_adjust_falloww"
@@ -385,16 +426,6 @@ class TWEAKLAT_OT_Remove_Object(Operator):
         return {'FINISHED'}
 
 
-class TWEAKLAT_OT_Duplicate(Operator):
-    """Duplicate this Tweak Lattice set-up"""
-    bl_idname = "lattice.duplicate_tweak_setup"
-    bl_label = "Duplicate Tweak Lattice"
-    bl_options = {'REGISTER', 'UNDO', 'INTERNAL'}
-
-    def execute(self, context):
-        pass
-
-
 class TWEAKLAT_PT_Main(Panel):
     bl_space_type = 'VIEW_3D'
     bl_region_type = 'UI'
@@ -405,7 +436,7 @@ class TWEAKLAT_PT_Main(Panel):
     def poll(cls, context):
         hook, _lattice, _root = get_tweak_setup(context.object)
 
-        return context.object.type == 'MESH' or hook
+        return context.object and context.object.type == 'MESH' or hook
 
     def draw(self, context):
         layout = self.layout
@@ -427,6 +458,8 @@ class TWEAKLAT_PT_Main(Panel):
         layout.separator()
         layout.operator(TWEAKLAT_OT_Delete.bl_idname,
                         text='Delete Tweak Lattice', icon='TRASH')
+        layout.operator(TWEAKLAT_OT_Duplicate.bl_idname,
+                        text='Duplicate Tweak Lattice', icon='DUPLICATE')
 
         layout.separator()
         layout.label(text="Helper Objects")
@@ -497,6 +530,9 @@ class TWEAKLAT_PT_Main(Panel):
 
 def get_tweak_setup(obj: Object) -> Tuple[Object, Object, Object]:
     """Based on either the hook, lattice or root, return all three."""
+    if not obj:
+        return [None, None, None]
+
     if obj.type == 'EMPTY':
         if 'Root' and 'Lattice' in obj:
             return obj, obj['Lattice'], obj['Root']
@@ -560,10 +596,10 @@ def add_radius_constraint(obj, hook, target):
 
 def get_objects_of_lattice(hook: Object) -> List[Object]:
     objs = []
-    ob_count = 0
+    for key, value in hook.items():
-    ob_prop_name = "object_"+str(ob_count)
+        if key.startswith("object_") and value:
-    while ob_prop_name in hook:
+            objs.append(value)
-        objs.append(hook[ob_prop_name])
+
     return objs
 
 
@@ -579,20 +615,20 @@ def add_objects_to_lattice(
         objects: List[Object]):
     lattice_ob = hook['Lattice']
 
-    # Check for existing
-    offset = 0
-    while "object_"+str(offset) in hook:
-        offset += 1
-
     for i, o in enumerate(objects):
         o.select_set(False)
         if o.type != 'MESH' or o in hook.values():
-            offset -= 1
             continue
-        m = o.modifiers.new(name="Tweak Lattice", type='LATTICE')
+        m = o.modifiers.new(name=lattice_ob.name, type='LATTICE')
         m.object = lattice_ob
+
+        # Make sure the property name is available.
+        offset = 0
+        while "object_"+str(offset) in hook:
+            offset += 1
         hook["object_"+str(i+offset)] = o
-        # Add driver to the modifier influence
+
+        # Add driver to the modifier influence.
         simple_driver(m, 'strength', hook, '["Tweak Lattice"]')
 
 
@@ -628,6 +664,7 @@ def remove_objects_from_lattice(hook, objects):
 
 classes = [
     TWEAKLAT_OT_Create,
+    TWEAKLAT_OT_Duplicate,
     TWEAKLAT_OT_Delete,
     TWEAKLAT_OT_Falloff,
     TWEAKLAT_OT_Add_Objects,