topic Find all the points inside a polyline in .NET Forum

Find all the points inside a polyline

Anonymous — Mon, 05 Jun 2017 14:40:04 GMT

Hi, I am looking for a way to find all the points inside a polyline, enclosed and not enclosed. Thanks!

Re: Find all the points inside a polyline

ActivistInvestor — Mon, 05 Jun 2017 15:24:33 GMT

Search this discussion group for the keyword "PointContainment"

Re: Find all the points inside a polyline

_gile — Mon, 05 Jun 2017 15:35:38 GMT

Hi,

As @ActivistInvestor (is it you Tony?) said, you'll find some ways to evaluate if a point is inside a polyline from this thread.

Anyway, if the polyline does not have bulges (i.e., a polygon) you can also try a more trivial way using a polygonal selection.

        [CommandMethod("TEST")]
        public void Test()
        {
            var doc = Application.DocumentManager.MdiActiveDocument;
            var db = doc.Database;
            var ed = doc.Editor;

            var options = new PromptEntityOptions("\nSelect a polyline: ");
            options.SetRejectMessage("\nSelected object is not a polyline.");
            options.AddAllowedClass(typeof(Polyline), true);
            var result = ed.GetEntity(options);
            if (result.Status != PromptStatus.OK)
                return;

            var polygon = new Point3dCollection();
            var ucs = ed.CurrentUserCoordinateSystem;
            Extents3d extents;
            using (var tr = db.TransactionManager.StartOpenCloseTransaction())
            {
                var pline = (Polyline)tr.GetObject(result.ObjectId, OpenMode.ForRead);
                extents = pline.GeometricExtents;
                for (int i = 0; i < pline.NumberOfVertices; i++)
                {
                    polygon.Add(pline.GetPoint3dAt(i).TransformBy(ucs));
                }
                tr.Commit();
            }

            var filter = new SelectionFilter(new[] { new TypedValue(0, "POINT") });
            dynamic acadApp = Application.AcadApplication;
            acadApp.ZoomWindow(extents.MinPoint.ToArray(), extents.MaxPoint.ToArray());
            var selection = ed.SelectCrossingPolygon(polygon, filter);
            acadApp.ZoomPrevious();
            if (selection.Status == PromptStatus.OK)
                ed.SetImpliedSelection(selection.Value);
        }

Re: Find all the points inside a polyline

Anonymous — Mon, 05 Jun 2017 20:45:16 GMT

Thanks _gile!

The link you directed me to worked really well. Code worked very well if I am picking the point manually but in our case we have to find enclosed or intersecting entity inside a enclosed polyline.

Suppose EntA is enclosed structure, EntB is inside or on the border. EntB can be closed or not closed object.

Instead of me selecting a point manually if I can know all the points on EntB I can really use this code. Or if there is any other suggestion you have it is greatly appreciated.

Re: Find all the points inside a polyline

_gile — Mon, 05 Jun 2017 20:58:19 GMT

Did you read / try the code I provided upper?

Re: Find all the points inside a polyline

BKSpurgeon — Tue, 06 Jun 2017 00:13:14 GMT

why not calculate the intersection points of the two entities and then incorporate that into Gilles' code?

Re: Find all the points inside a polyline

Anonymous — Tue, 06 Jun 2017 13:39:03 GMT

Yes I did. My selection is empty. Here's the screen shot.

Re: Find all the points inside a polyline

_gile — Tue, 06 Jun 2017 14:53:47 GMT

The code I puposed make a filtered selection of the points (DBPoint entities) inside the polyline becaus it was my understanding of your first message.

If you want to select anothe type of entities, modify the selection filter to suit your needs.

Re: Find all the points inside a polyline

Anonymous — Thu, 08 Jun 2017 15:24:37 GMT

Thank you _gile this discussion was very helpful!