- next_unit = max((u.unit+1 for u in self.uv_layers if u.unit is not None), default=0)
- for u in self.uv_layers:
- if not u.unit:
- u.unit = next_unit
- next_unit += 1
+ missing_unit = [u for u in self.uv_layers if u.unit is None]
+ if missing_unit:
+ missing_unit = sorted(missing_unit, key=(lambda u: u.name))
+ used_units = [u.unit for u in self.uv_layers if u.unit is not None]
+ for u, n in zip(missing_unit, (i for i in itertools.count() if i not in used_units)):
+ u.unit = n
+
+ self.uv_layers = sorted(self.uv_layers, key=(lambda u: u.unit))
+
+ if mesh.use_uv=='UNIT0':
+ self.uv_layers = [self.uv_layers[0]]
+ if self.uv_layers[0].unit!=0:
+ self.uv_layers = []