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IDProjectCategoryView StatusDate SubmittedLast Update
0023463CommunityOCCT:Modeling Algorithmspublic2012-10-08 17:582012-10-08 17:58
ReporterVitezslav Zajic Assigned Tojgv 
PrioritynormalSeverityminor 
Status newResolutionopen 
PlatformWindowsOSVC++ 2010 
Product Version6.5.3 
Summary0023463: Boolean operations provide wrong results for solids with faces formed by bspline surfaces.
DescriptionBoolean operations (common, cut and fuse) on two same solids (one rotated by 90° around the z-axis, see attached solid.png for the picture of one of the solids) with faces made of simple bspline surfaces provide wrong results (no new solid is created even though there should be exactly one resulting solid for each of the operations). However, this happens only if both solids have their centers in the same point, if you translate one of the solids a little, boolean operations works fine.
Steps To ReproduceThe following code creates the described solids, then performs the boolean operation out checks the result:

  TColgp_Array2OfPnt poles(1, 2, 1, 2);
  poles.SetValue(1, 1, gp_Pnt(0.0, -5.0, 0.0));
  poles.SetValue(2, 1, gp_Pnt(5.0, 0.0, 0.0));
  poles.SetValue(1, 2, gp_Pnt(0.0, 0.0, 5.0));
  poles.SetValue(2, 2, gp_Pnt(0.0, 5.0, 0.0));
  TColStd_Array1OfReal uknots(1, 2);
  uknots.SetValue(1, 0.0);
  uknots.SetValue(2, 1.0);
  TColStd_Array1OfInteger umults(1, 2);
  umults.SetValue(1, 2);
  umults.SetValue(2, 2);
  TColStd_Array1OfReal vknots(1, 2);
  vknots.SetValue(1, 0.0);
  vknots.SetValue(2, 1.0);
  TColStd_Array1OfInteger vmults(1, 2);
  vmults.SetValue(1, 2);
  vmults.SetValue(2, 2);

  Handle(Geom_BSplineSurface) surface = new Geom_BSplineSurface(poles, uknots, vknots, umults, vmults, 1, 1);

  BRepBuilderAPI_MakeFace face1Builder(surface, 0.0);
  assert(face1Builder.IsDone());
  
  BRepBuilderAPI_MakeFace face2Builder(Handle(Geom_Surface)::DownCast(surface->Mirrored(gp_Ax2(gp_Pnt(0.0, 0.0, 0.0), gp_Dir(1.0, 0.0, 0.0)))), 0.0);
  assert(face2Builder.IsDone());

  BRepBuilderAPI_MakeFace face3Builder(Handle(Geom_Surface)::DownCast(surface->Mirrored(gp_Ax2(gp_Pnt(0.0, 0.0, 0.0), gp_Dir(0.0, 0.0, 1.0)))), 0.0);
  assert(face3Builder.IsDone());

  BRepBuilderAPI_MakeFace face4Builder(Handle(Geom_Surface)::DownCast(surface->Mirrored(gp_Ax1(gp_Pnt(0.0, 0.0, 0.0), gp_Dir(0.0, 1.0, 0.0)))), 0.0);
  assert(face4Builder.IsDone());

  BRepBuilderAPI_Sewing shellBuilder;
  shellBuilder.Add(face1Builder.Shape());
  shellBuilder.Add(face2Builder.Shape());
  shellBuilder.Add(face3Builder.Shape());
  shellBuilder.Add(face4Builder.Shape());
  shellBuilder.Perform();
  TopoDS_Shell shell = TopoDS::Shell(shellBuilder.SewedShape());

  BRepBuilderAPI_MakeSolid solidBuilder(shell);
  assert(solidBuilder.IsDone());
  TopoDS_Solid solid1 = solidBuilder.Solid();

  gp_Trsf rotation;
  rotation.SetRotation(gp_Ax1(gp_Pnt(0.0, 0.0, 0.0), gp_Dir(0.0, 0.0, 1.0)), M_PI / 2.0); // Change the rotation a little and boolean operations will start to work.
  gp_Trsf translation;
  translation.SetTranslation(gp_Vec(0.0, 0.0, 0.0)); // Change the translation to be non-zero and boolean operations will start to work.

  BRepBuilderAPI_Transform rotate(solid1, rotation);
  assert(rotate.IsDone());

  BRepBuilderAPI_Transform translate(rotate.Shape(), translation);
  assert(translate.IsDone());

  TopoDS_Solid solid2 = TopoDS::Solid(translate.Shape());

  BRepAlgo_Common common(solid1, solid2); // Fuse and cut also provide wrong results for this case.
  assert(common.IsDone());
  TopoDS_Shape shape = common.Shape();
  TopExp_Explorer exp(shape, TopAbs_SOLID);
  unsigned int count = 0;
  for ( ; exp.More(); exp.Next())
  {
    ++count;
  }
  std::cout << "Common created " << count << " of solids." << std::endl; // This prints zero, but the common should create one new solid.
TagsNo tags attached.
Test case number

Attached Files

  • solid.png (30,059 bytes)

Activities

Vitezslav Zajic

2012-10-08 17:58

reporter  

solid.png (30,059 bytes)

Issue History

Date Modified Username Field Change
2012-10-08 17:58 Vitezslav Zajic New Issue
2012-10-08 17:58 Vitezslav Zajic Assigned To => jgv
2012-10-08 17:58 Vitezslav Zajic File Added: solid.png