Error in RhinoCommon API Brep Faces

Hello can anyone help me with the faces in the brep class. When generating it only 3 faces list. When baked into the gui it showns all faces in the brep object. It look like it is interpeting it als a folded single surface.

 Func<Brep> FindCut = () =>
                Brep brep = null;
                var tp = new Plane(this.Axis.PointAt(0.5), this.Plane.ZAxis, this.Plane.XAxis);
                Rhino.Geometry.Intersect.Intersection.BrepPlane(Container.Input, tp, 0.1, out Curve[x] crvs, out Point3d[x] pts);
                if (crvs != null && crvs.Count() > 0 && crvs[0].IsClosed)
                    Curve tc = crvs[0];
                    tc.Translate(-this.Axis.Direction / 2.0);

                    var lst = tc.DuplicateSegments().ToList();
                    ("crv count " + lst.Count).Show();
                 var bs =  tc.DuplicateSegments().ToList().ConvertAll(x =>
                       return Extrusion.CreateExtrusion(tc, Axis.Direction).ToBrep();

                    brep = Brep.JoinBreps(bs, 0.1)[0];
                    ("TEST2" + brep.Faces.Count).Show();
                    if (brep.SolidOrientation == BrepSolidOrientation.Inward) {brep.Flip();}

                return brep;

Hi @michael.sprinzl,

Can you explain what it is you want this code to do? And you also provide a model that has the geoemtry you are running this code against?

– Dale

Hi Dale,
Ok it is a part converter for rhino to tekla. What i try to find out cuts in profiles. The Problem is what the function
Extrusion.CreateExtrusion(tc, Axis.Direction).ToBrep();
Only gives me 1 Face when in Code. When baked into the DocObject it is ok. But I want to process this within the code. This must be a mistace in the RhinoCommon. Try to extrude a Polyline. And when look at the face count.


Ok I give you an example code which is more reasonable:

    public static void ErrorTest() 
        var i = new Interval(-50, 50);
        var p = new Rectangle3d(Rhino.Geometry.Plane.WorldXY, i, i).ToNurbsCurve();
        var r = new Line(new Point3d(0,0,0), new Point3d(0, 0, 500)).ToNurbsCurve();
        var b = Rhino.Geometry.Brep.CreateFromSweep(r, p, true, 0.1)[0];
        Rhino.RhinoApp.WriteLine("faces:" + b.Faces.Count);

Gives you this in Rhino:

But only one face, this should be at least 4 faces:

Hi @michael.sprinzl,

See if this is helpful:

protected override Result RunCommand(RhinoDoc doc, RunMode mode)
  var interval = new Interval(-50, 50);
  var rectangle = new Rectangle3d(Plane.WorldXY, interval, interval);
  var shape = new PolylineCurve(rectangle.ToPolyline());
  var rail = new LineCurve(new Point3d(0, 0, 0), new Point3d(0, 0, 500));
  var tolerance = RhinoDoc.ActiveDoc.ModelAbsoluteTolerance;
  var out_breps = Rhino.Geometry.Brep.CreateFromSweep(rail, shape, true, tolerance);
  if (null != out_breps && out_breps.Length > 0)
    var brep = out_breps[0];
    // The rail and shape curves are degree=1 curves. Thus, the underlying surface 
    // will have kinks. Because kinked surface can cause problems down stream, Rhino
    // always splits kinked surfaces when adding Breps to the document. Since
    // we are not adding this Brep to the document, lets split the kinked
    // surfaces ourself.
    RhinoApp.WriteLine("Face count: " + brep.Faces.Count);
  return Result.Success;

– Dale

Hi Dale, thank you very much. This helps.