public void Remove(Selectable obj)
 {
     selectedObjects.Remove(obj);
     SelectionChanged.Invoke(this);
     ObjectsRemoved.Invoke(this, new Selectable[] { obj });
     CalculateCenter();
 }
 public void Clear()
 {
     if (selectedObjects.Count > 0)
     {
         var objs = selectedObjects.ToArray();
         selectedObjects.Clear();
         SelectionChanged.Invoke(this);
         ObjectsRemoved.Invoke(this, objs);
         Center = Vector3.zero;
     }
 }