internal static void MarkObstacleArea(List <Vector3> pts, CellManager cellMgr, byte obstacle)
        {
            List <CellPos> cells = cellMgr.GetCellsInPolygon(pts);

            foreach (CellPos cell in cells)
            {
                cellMgr.SetCellStatus(cell.row, cell.col, obstacle);
            }
        }