topic Re: Polyline3d intersect in .NET Forum

Polyline3d intersect

Anonymous — Fri, 12 May 2006 02:49:02 GMT

Hello everyone,

1. How to get the intersection of 2 Polyline3d in different plane?
I tried using IntersectWith() but it return no intersection because the polylines lies in different plane.
2. How about Aparent Intersect? Is there anyone who can teach me how to implement this in my C# code?

Thank you.

GS

Re: Polyline3d intersect

Anonymous — Fri, 12 May 2006 13:08:35 GMT

What about create projections of those Polyline3d on single plan (with help of Polyline3d.GetProjectedCurve method)?
After than you can do IntersectWith() with projections.

Re: Polyline3d intersect

Anonymous — Sat, 13 May 2006 06:35:15 GMT

Dear Alexander Rivilis,

I'll do that. Thank you.

GS

Re: Polyline3d intersect

Anonymous — Sat, 13 May 2006 06:46:09 GMT

Dear Alexander Rivilis,

I'll appreciate if you can show me a snippet code how to do it.
Thank you in advance.

GS

Re: Polyline3d intersect

Anonymous — Sat, 13 May 2006 08:55:05 GMT

[code]
using System ;
using System.Collections;
using Autodesk.AutoCAD.Runtime ;
using Autodesk.AutoCAD.DatabaseServices;
using Autodesk.AutoCAD.Geometry;
using Autodesk.AutoCAD.EditorInput;
using Autodesk.AutoCAD.ApplicationServices;
using AcadApp = Autodesk.AutoCAD.ApplicationServices.Application;

[assembly: CommandClass(typeof(ClassLibrary.Class))]

namespace ClassLibrary
{
public class Class
{
[CommandMethod("IntPoly3d")]
static public void IntPoly3d()
{
Editor ed = Application.DocumentManager.MdiActiveDocument.Editor;
Polyline3d pl1 = SelectPoly3d("\nSelect first Polyline3d: ");
if (pl1 == null) return;
Polyline3d pl2 = SelectPoly3d("\nSelect second Polyline3d: ");
if (pl2 == null) return;
// We can project our plines in direction of Z axis of WCS,
// but you can use another project plane
Vector3d dir = new Vector3d(0,0,1);
Point3d orig = new Point3d (0,0,0);
// Plane of WCS
Plane planeWCS = new Plane(orig, dir);
Curve pl1_prj = pl1.GetProjectedCurve(planeWCS,dir); pl1.Dispose();
Curve pl2_prj = pl2.GetProjectedCurve(planeWCS,dir); pl2.Dispose();
Point3dCollection pts = new Point3dCollection();
pl1_prj.IntersectWith(pl2_prj,Intersect.OnBothOperands,pts,0,0);
if (pts.Count > 0)
{
ed.WriteMessage("\nNumber of intersection: {0}",pts.Count);
foreach (Point3d pt in pts) ed.WriteMessage("\n Point: {0}",pt);
}
else
{
ed.WriteMessage("\nNo intersection!");
}
pl1_prj.Dispose(); pl2_prj.Dispose();
}
static private Polyline3d SelectPoly3d(string str)
{
Editor ed = Application.DocumentManager.MdiActiveDocument.Editor;
Database db = HostApplicationServices.WorkingDatabase;
PromptEntityResult rs = ed.GetEntity(str);
if (rs.Status == PromptStatus.OK)
{
Transaction trans = db.TransactionManager.StartTransaction();
Entity ent = (Entity)trans.GetObject(rs.ObjectId, OpenMode.ForRead);
Polyline3d pl = ent as Polyline3d;
trans.Commit();
if (pl == null) ed.WriteMessage("\nIt is not Polyline3d!");
return pl;
}
return null;
}
}
}
[/code]

Re: Polyline3d intersect

Anonymous — Mon, 15 May 2006 04:36:40 GMT

Dear Alexander Rivilis,
Thank you so much to your help it helps me a lot however its my mistake that I was not able to inform you that I need also the value of Z coordinate. What should I do so that I get also get it like Apparent Intersect does?
Once again thank you.

GS