RemoveHoles method doesn’t work

Hi everyone,

I am trying to close an inner hole with this script but it returns a null. Does anyone know what I am doing wrong?

Thank you!

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The general - explicit - case of this (any valid Brep List - where Brep can contain one or many BrepFaces with Outer/Inner Loops blah, blah) has as follows:

public DataTree<Brep> bTree;
  static double tol = RhinoDoc.ActiveDoc.ModelAbsoluteTolerance;
  static Random random = new Random();

  public void RemoveLoops(List<Brep> bList, int mode){

    for(int i = 0; i < bList.Count;i++){
      Brep brep = bList[i];
      List<Brep> newBrepFaces = new List<Brep>();
      for(int j = 0;j < brep.Faces.Count;j++){
        BrepFace face = brep.Faces[j];
        if(face.IsSurface){ // mode here has no meaning (for obvious reasons)
          Print("At: {0},{1} Face is Surface", i, j);

        Surface s = face.UnderlyingSurface();
        Brep sb = s.ToBrep(); BrepFace sbf = sb.Faces[0];

        List<Curve> splitCrvs = new List<Curve>();
        if(mode == 1) {
          foreach(BrepLoop loop in face.Loops){
            if (loop.LoopType == BrepLoopType.Inner){

        Brep newBrep = sbf.Split(splitCrvs, tol);
        newBrep = GetCorrectPiece(newBrep, face);

        if(newBrep != null) newBrepFaces.Add(newBrep);
        else Print("Split error at: {0},{1}", i, j);

        if(mode == 1) {
          bTree.AddRange(newBrepFaces, new GH_Path(i));
          Brep[] newBreps = Brep.JoinBreps(newBrepFaces, tol);
          if(newBreps != null && newBreps.Length > 0){
            bTree.AddRange(newBreps, new GH_Path(i));
      else Print("Major error at: {0}", i);

  public Brep GetCorrectPiece(Brep b, BrepFace face){
    u = face.Domain(0); v = face.Domain(1);
    foreach(BrepFace f in b.Faces){
      Point3d p = GetPoint(f);
      double up, vp; face.ClosestPoint(p, out up, out vp);
      PointFaceRelation pfr = face.IsPointOnFace(up, vp);
      if(pfr != PointFaceRelation.Exterior){
        return f.DuplicateFace(true);
    return null;

  public Interval u, v;

  private Point3d GetPoint(BrepFace face){
      double randu = u.ParameterAt(random.NextDouble());
      double randv = v.ParameterAt(random.NextDouble());
      if (face.IsPointOnFace(randu, randv) == PointFaceRelation.Interior)return face.PointAt(randu, randv);

So … If you can translate C# to P … notify

BTW: If a given Brep has Faces that are not a Surface AND you want to remove the Outer Loop … then Joining has no meaning … so you get a collection of Breps.

Isn’t the output supposed to be a =, not newBrep = ?
And y is the tolerance, so providing it 2 may be overkill.

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