private static void toggleSpriteGroups(Human human, JointSprite sprite) {
    for (String groupName : ((JointModel) sprite.model()).groupNames()) {
      boolean valid = "Main Body".equals(groupName) ;
      final DeviceType DT = human.gear.deviceType() ;
      if (DT != null && DT.groupName.equals(groupName)) valid = true ;
      if (! valid) sprite.toggleGroup(groupName, false) ;
    }
  }