private void UpdateGeometry(Vertex v)
        {
            VertexData vd = mode.GetVertexData(v);

            foreach (KeyValuePair <Sector, bool> s in vd.UpdateAlso)
            {
                if (mode.VisualSectorExists(s.Key))
                {
                    BaseVisualSector vs = (BaseVisualSector)mode.GetVisualSector(s.Key);
                    vs.UpdateSectorGeometry(s.Value);
                }
            }
        }