Surface.IsCylinder

Rhino Developer
1

I check a face in my brepbody and it is detected as cylinder, after I translate the cylindrical surface, it
return face.IsCylinder as false why?

2

same here…

3 
RhinoDoc activeDoc = RhinoDoc.ActiveDoc;
    IEnumerable<RhinoObject> brepObjects = activeDoc.Objects.GetObjectList(ObjectType.Brep);
    RhinoObject object1 = brepObjects.ElementAt(0);

    bool hasBrepForm = object1.Geometry.HasBrepForm;

    if (hasBrepForm)
    {
      Brep brepBody = Brep.TryConvertBrep(object1.Geometry);
      brepBody.MakeDeformable();
      BrepFace face1 = brepBody.Faces.ElementAt(2);
      ComponentIndex index = face1.ComponentIndex();
      IEnumerable<ComponentIndex> componentIndices = new List<ComponentIndex> { index };
      BrepEdge edge1 = Get_edge(brepBody, face1);

      Cylinder cylinder;
      Plane plane;
      face1.TryGetCylinder(out cylinder);
      bool Isplane = face1.TryGetPlane(out plane);

      Transform transform;
      if (face1.IsCylinder())
      {
        Vector3d vector = cylinder.BasePlane.Normal;
        Plane plane1 = cylinder.BasePlane;

        double tolerance = 0;
        double timeLimit = 0.0;
        bool useMultipleThreads = false;
        double scalefactor = 2;

        Point3d point = cylinder.Center;
        transform = Transform.Scale(plane1, scalefactor, scalefactor, 1);
        //transform = Transform.Translation(20, 20, 1);

        brepBody.TransformComponent(componentIndices, transform, tolerance, timeLimit, useMultipleThreads);

      
        activeDoc.Views.Redraw();
        object1.CommitChanges();
      }
      else if (Isplane)
      {
        double tolerance = activeDoc.ModelAbsoluteTolerance;
        double timeLimit = 10.0;
        bool useMultipleThreads = true;
        //Transform transform = Transform.Translation(0, -10, 0);
        //brepBody.TransformComponent(componentIndices, transform, tolerance, timeLimit, useMultipleThreads);
        activeDoc.Views.Redraw();
        object1.CommitChanges();

      }
      //Pickup an outer surface





    }
    else
    {
      A = "its not a brep body";
    }

Here is the code to select a surface and if found cylindrical scale its diameter. When run first time though a script tag in grasshopper it increases the dia but when run again it dosent do the change thereafter if the same cylinderical surface is to be scaled.

4

Here is the file
filetosee2.3dm (818.8 KB)

5

Hi @Rushank,

This seems to work with your model:

protected override Result RunCommand(RhinoDoc doc, RunMode mode)
{
  var go = new GetObject
  {
    GeometryFilter = ObjectType.Surface,
    GeometryAttributeFilter = GeometryAttributeFilter.SubSurface
  };
  go.SetCommandPrompt("Select cylindrical face");
  go.Get();
  if (go.CommandResult() != Result.Success)
    return go.CommandResult();

  var brepFace = go.Object(0).Face();
  if (null == brepFace)
    return Result.Failure;

  var tol = doc.ModelAbsoluteTolerance;
  var rc = brepFace.IsCylinder(tol);
  if (rc)
  {
    RhinoApp.WriteLine("IsCylinder = {0}", rc);
    rc = brepFace.TryGetFiniteCylinder(out var cylinder, tol);
    if (rc)
    {
      var brep = Brep.CreateFromCylinder(cylinder, false, false);
      if (null != brep)
      {
        var id = doc.Objects.AddBrep(brep);
        var rhObj = doc.Objects.Find(id);
        rhObj?.Select(true);
      }
    }
  }
  doc.Views.Redraw();

  return Result.Success;
}

– Dale

6

Thanks Dale