public static Polyline ConvertToPolyline(this Polyline3d line3d) { var points = line3d.GetPoints().ToEnumerable().ToList(); Polyline pline = new Polyline(points.Count()); int i = 0; points.ForEach(p => { pline.AddVertexAt(i++, p); }); return(pline); /*Polyline pline = new Polyline(); * pline.ConvertFrom(line3d, false); * return pline*/ }