private static Point3dCollection GetNonRectClipBoundary(
Polyline2d polyline, Transaction tran)
{
Point3dCollection points = new Point3dCollection();
foreach (ObjectId vxId in polyline)
{
Vertex2d vx = (Vertex2d)tran.GetObject(vxId, OpenMode.ForRead);
points.Add(polyline.VertexPosition(vx));
}
return(points);
}