HiddenLineDrawingSegment not supporting Clipped segments?

It seems that “Rhino.Geometry.HiddenLineDrawingSegment.Visibility.Clipped” type is currently not supported.
Whenever I define a clipping plane and Compute, only visible and hidden segments are returned, but never clipped segments.
@DavidRutten also excluded the clipped curves as outputs of the “Make2D” grasshopper component.
Does that mean that “Clipped” segments are currently not supported by “HiddenLineDrawingSegment” class?

@djordje what do you need the HiddenLineDrawingSegment.Visibility.Clipped segments for?
Are you trying to find ClippingPlane intersections with your geometry?

Hi @rajaa,

Yes. I have an object in the perspective view, and I would like to “identify” the clipping plane Make2D lines. But the “HiddenLineDrawingSegment.Visibility.Clipped” seens to not work.

Ok, I’ll put together a sample for you to extract intersection curves with the clipping plane.

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This code will select objects and use active clipping plane to output Make2D curves.
Is that what you are looking for?

      var _go = new GetObject();
      _go.SetCommandPrompt("Select objects to test Make2D");
      _go.GeometryFilter = ObjectType.Point | ObjectType.Surface | ObjectType.PolysrfFilter;
      _go.GroupSelect = true;
      _go.GetMultiple(1, 0);
      if (_go.CommandResult() != Result.Success)
        return _go.CommandResult();
      var _obj_refs = _go.Objects();
      var _view = doc.Views.ActiveView;
      //Set Make2D Parameters
      var _hld_params = new HiddenLineDrawingParameters
        AbsoluteTolerance = doc.ModelAbsoluteTolerance,
        IncludeTangentEdges = false,
        IncludeHiddenCurves = true

      //add objects to hld_param
      foreach (var obj_ref in _obj_refs)
        if (null == obj_ref)
        var obj = obj_ref.Object();
        if (null == obj)
        _hld_params.AddGeometry(obj.Geometry, Transform.Identity, obj.Id);

      //Add active clipping planes
      var clipping_planes = doc.Objects.GetObjectsByType<ClippingPlaneObject>().ToArray();
      foreach (var clipping_plane in clipping_planes)
        if (clipping_plane.ClippingPlaneGeometry.ViewportIds().Contains(_view.ActiveViewport.Id))
          var plane = clipping_plane.ClippingPlaneGeometry.Plane;

      //perform HLD calculation
      var _hld = HiddenLineDrawing.Compute(_hld_params, true);
      if (_hld != null)
        //transform and add to doc
        var flatten = Transform.PlanarProjection(Plane.WorldXY);
        BoundingBox page_box = _hld.BoundingBox(true);
        var delta2D = new Vector2d(0, 0);
        delta2D = delta2D - new Vector2d(page_box.Min.X, page_box.Min.Y);
        var delta3D = Transform.Translation(new Vector3d(delta2D.X, delta2D.Y, 0.0));
        flatten = delta3D * flatten;
        //add curves to doc
        var h_attribs = new ObjectAttributes();
        h_attribs.Name = "H";
        h_attribs.ColorSource = ObjectColorSource.ColorFromObject;
        h_attribs.ObjectColor = System.Drawing.Color.Cyan;
        var v_attribs = new ObjectAttributes();
        v_attribs.Name = "V";
        var cv_attribs = new ObjectAttributes();
        cv_attribs.Name = "CutV";
        cv_attribs.ColorSource = ObjectColorSource.ColorFromObject;
        cv_attribs.ObjectColor = System.Drawing.Color.Red;
        var ch_attribs = new ObjectAttributes();
        ch_attribs.Name = "CutH";
        ch_attribs.ColorSource = ObjectColorSource.ColorFromObject;
        ch_attribs.ObjectColor = System.Drawing.Color.Pink;
        foreach (HiddenLineDrawingSegment hld_curve in _hld.Segments)
          if (hld_curve == null || hld_curve.ParentCurve == null || hld_curve.ParentCurve.SilhouetteType == SilhouetteType.None)
          var crv = hld_curve.CurveGeometry.DuplicateCurve();
          if (crv != null)
            if (hld_curve.SegmentVisibility == HiddenLineDrawingSegment.Visibility.Visible)
              if (hld_curve.ParentCurve.SilhouetteType == SilhouetteType.SectionCut)
                doc.Objects.AddCurve(crv, cv_attribs);
                doc.Objects.AddCurve(crv, v_attribs);
            else if (hld_curve.SegmentVisibility == HiddenLineDrawingSegment.Visibility.Hidden)
              if (hld_curve.ParentCurve.SilhouetteType == SilhouetteType.SectionCut)
                doc.Objects.AddCurve(crv, ch_attribs);
                doc.Objects.AddCurve(crv, h_attribs);
        //add points to doc
        foreach (HiddenLineDrawingPoint hld_pt in _hld.Points)
          if (hld_pt == null)
          var pt = hld_pt.Location;
          if (pt != null)
            if (hld_pt.PointVisibility == HiddenLineDrawingPoint.Visibility.Visible)
              doc.Objects.AddPoint(pt, v_attribs);
            else if (hld_pt.PointVisibility == HiddenLineDrawingPoint.Visibility.Hidden)
              doc.Objects.AddPoint(pt, h_attribs);
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