void ScaleDownLooseHierarchy(InteractiveEdgeRouter interactiveEdgeRouter, Set<Shape> obstacleShapes) {
            var loosePolys = new List<Polyline>();
            foreach (var obstacleShape in obstacleShapes) {
                var tl = shapesToTightLooseCouples[obstacleShape];
                loosePolys.Add( InteractiveObstacleCalculator.LoosePolylineWithFewCorners(tl.TightPolyline, tl.Distance / BundleRouter.SuperLoosePaddingCoefficient));
            }

            interactiveEdgeRouter.LooseHierarchy=CreateLooseObstacleHierarachy(loosePolys);
                
            interactiveEdgeRouter.ClearActivePolygons();

            interactiveEdgeRouter.AddActivePolygons(loosePolys.Select(polyline => new Polygon(polyline)));         
        }