0032307: Modeling Algorithms - Empty result of offset operation in mode "Complete" Joint type "Intersection"

Make sure the vertices created by pairwise intersection of edges connected in the same vertex are unified correctly.

src/BRepOffset/BRepOffset_Inter2d.cxx

@@ -64,6 +64,7 @@
 #include <gp_Pnt.hxx>
 #include <IntRes2d_IntersectionPoint.hxx>
 #include <IntRes2d_IntersectionSegment.hxx>
+#include <IntTools_Tools.hxx>
 #include <Precision.hxx>
 #include <TColGeom2d_SequenceOfCurve.hxx>
 #include <TColgp_Array1OfPnt2d.hxx>
@@ -278,6 +279,14 @@ static void Store(const TopoDS_Edge& theEdge,
                   Handle(BRepAlgo_AsDes) theAsDes2d,
                   TopTools_IndexedDataMapOfShapeListOfShape& theDMVV)
 {
+  // Update vertices
+  TopTools_ListIteratorOfListOfShape aIt(theLV);
+  for (; aIt.More(); aIt.Next()) {
+    const TopoDS_Vertex& aV = TopoDS::Vertex(aIt.Value());
+    BRep_Builder().UpdateVertex(aV, theTol);
+  }
+
+  // Get vertices already added to the edge and check the distances to the new ones
   const TopTools_ListOfShape& aLVEx = theAsDes2d->Descendant(theEdge);
   if (!IsToUpdate && aLVEx.IsEmpty()) {
     if (theLV.Extent()) theAsDes2d->Add(theEdge, theLV);
@@ -285,21 +294,23 @@ static void Store(const TopoDS_Edge& theEdge,
   }
   //
   GeomAPI_ProjectPointOnCurve aProjPC;
+  Standard_Real aTolE = 0.0;
   if (IsToUpdate) {
     Standard_Real aT1, aT2;
     const Handle(Geom_Curve)& aC = BRep_Tool::Curve(theEdge, aT1, aT2);
     aProjPC.Init(aC, aT1, aT2);
+    aTolE = BRep_Tool::Tolerance(theEdge);
   }
   //
   TopTools_MapOfShape aMV;
-  TopTools_ListIteratorOfListOfShape aIt(theLV);
+  for (aIt.Init(theLV); aIt.More(); aIt.Next()) {
-  for (; aIt.More(); aIt.Next()) {
     const TopoDS_Vertex& aV = TopoDS::Vertex(aIt.Value());
     if (!aMV.Add(aV)) {
       continue;
     }
     //
     const gp_Pnt& aP = BRep_Tool::Pnt(aV);
+    const Standard_Real aTol = BRep_Tool::Tolerance(aV);
     //
     TopTools_ListOfShape aLVC;
     TopTools_ListIteratorOfListOfShape aItEx(aLVEx);
@@ -309,7 +320,8 @@ static void Store(const TopoDS_Edge& theEdge,
         break;
       }
       const gp_Pnt& aPEx = BRep_Tool::Pnt(aVEx);
-      if (aP.IsEqual(aPEx, theTol)) {
+      const Standard_Real aTolVEx = BRep_Tool::Tolerance(aVEx);
+      if (aP.IsEqual(aPEx, aTol + aTolVEx)) {
         aLVC.Append(aVEx);
       }
     }
@@ -325,16 +337,13 @@ static void Store(const TopoDS_Edge& theEdge,
         continue;
       }
       //
-      if (aProjPC.LowerDistance() > theTol) {
+      if (aProjPC.LowerDistance() > aTol + aTolE) {
         continue;
       }
       //
       Standard_Real aT = aProjPC.LowerDistanceParameter();
       TopoDS_Shape aLocalShape = aV.Oriented(TopAbs_INTERNAL);
-      BRep_Builder().UpdateVertex(TopoDS::Vertex(aLocalShape), aT, theEdge, theTol);
+      BRep_Builder().UpdateVertex(TopoDS::Vertex(aLocalShape), aT, theEdge, aTol);
-    }
-    else {
-      BRep_Builder().UpdateVertex(aV, theTol);
     }
     //
     if (aLVC.Extent()) {
@@ -672,7 +681,7 @@ static void RefEdgeInter(const TopoDS_Face&              F,
     return;
 
   Standard_Real f[3],l[3];
-  Standard_Real TolDub = 1.e-7;
+  Standard_Real TolDub = 1.e-7, TolLL = 0.0;
   Standard_Integer i;
 
   //BRep_Tool::Range(E1, f[1], l[1]);
@@ -689,9 +698,6 @@ static void RefEdgeInter(const TopoDS_Face&              F,
   BRepLib::BuildCurve3d(E1);
   BRepLib::BuildCurve3d(E2);
 
-  Standard_Real TolSum = BRep_Tool::Tolerance(E1) + BRep_Tool::Tolerance(E2);
-  TolSum = Max( TolSum, 1.e-5 );
-
   TColgp_SequenceOfPnt   ResPoints;
   TColStd_SequenceOfReal ResParamsOnE1, ResParamsOnE2;
   gp_Pnt DegPoint;
@@ -721,11 +727,19 @@ static void RefEdgeInter(const TopoDS_Face&              F,
       (GAC2.GetType() == GeomAbs_Line))
   {
     // Just quickly check if lines coincide
-    if (GAC1.Line().Direction().IsParallel (GAC2.Line().Direction(), 1.e-8))
+    Standard_Real anAngle = Abs(GAC1.Line().Direction().Angle(GAC2.Line().Direction()));
+    if (anAngle <= 1.e-8 || M_PI - anAngle <= 1.e-8)
     {
       theCoincide = Standard_True;
       return;
     }
+    else
+    {
+      // Take into account the intersection range of line-line intersection
+      // (the smaller angle between curves, the bigger range)
+      TolLL = IntTools_Tools::ComputeIntRange(TolDub, TolDub, anAngle);
+      TolLL = Min (TolLL, 1.e-5);
+    }
   }
   
   Geom2dInt_GInter Inter2d( GAC1, GAC2, TolDub, TolDub );
@@ -943,10 +957,12 @@ static void RefEdgeInter(const TopoDS_Face&              F,
       else
         theImageVV.Bind (theVref.Oriented(TopAbs_FORWARD), aNewVertex);
     }
-      
+
 ////-----------------------------------------------------
     Standard_Real TolStore = BRep_Tool::Tolerance(E1) + BRep_Tool::Tolerance(E2);
     TolStore = Max (TolStore, Tol);
+    // Compare to Line-Line tolerance
+    TolStore = Max (TolStore, TolLL);
     Store (E1,E2,LV1,LV2,TolStore,AsDes, aDMVV);
   }
 }

src/BRepOffset/BRepOffset_MakeOffset_1.cxx

@@ -195,6 +195,12 @@ static
                          BRepOffset_DataMapOfShapeMapOfShape& theLocValidEdges,
                          BRepOffset_DataMapOfShapeMapOfShape& theNeutralEdges);
 
+static
+  void  MakeInvertedEdgesInvalid(const TopTools_ListOfShape& theLFOffset,
+                                 const TopTools_IndexedDataMapOfShapeListOfShape& theFImages,
+                                 const TopTools_MapOfShape& theInvertedEdges,
+                                 TopTools_IndexedMapOfShape& theInvEdges);
+
 static
   void FindInvalidFaces(TopTools_ListOfShape& theLFImages,
                         const TopTools_IndexedMapOfShape& theInvEdges,
@@ -1030,6 +1036,10 @@ void BuildSplitsOfFaces(const TopTools_ListOfShape& theLF,
   FindInvalidEdges (aLFDone, theFImages, theFacesOrigins, theAnalyse,
                     theInvEdges, theValidEdges, aDMFMIE, aDMFMVE, aDMFMNE);
 
+  // Additional step to mark inverted edges located inside loops
+  // of invalid edges as invalid as well
+  MakeInvertedEdgesInvalid(aLFDone, theFImages, theInvertedEdges, theInvEdges);
+
 #ifdef OFFSET_DEBUG
   // show invalid edges
   TopoDS_Compound aCEInv1;
@@ -2180,6 +2190,82 @@ void FindInvalidEdges (const TopTools_ListOfShape& theLFOffset,
   }
 }
 
+//=======================================================================
+//function : MakeInvertedEdgesInvalid
+//purpose  : Makes inverted edges located inside loop of invalid edges, invalid as well
+//=======================================================================
+void MakeInvertedEdgesInvalid(const TopTools_ListOfShape& theLFOffset,
+                              const TopTools_IndexedDataMapOfShapeListOfShape& theFImages,
+                              const TopTools_MapOfShape& theInvertedEdges,
+                              TopTools_IndexedMapOfShape& theInvEdges)
+{
+  if (theInvEdges.IsEmpty() || theInvertedEdges.IsEmpty())
+    return;
+
+  // Map all invalid edges
+  TopoDS_Compound aCBEInv;
+  BRep_Builder().MakeCompound(aCBEInv);
+  for (Standard_Integer i = 1; i <= theInvEdges.Extent(); ++i)
+  {
+    BRep_Builder().Add(aCBEInv, theInvEdges(i));
+  }
+
+  // Make loops of invalid edges
+  TopTools_ListOfShape aLCB;
+  BOPTools_AlgoTools::MakeConnexityBlocks(aCBEInv, TopAbs_VERTEX, TopAbs_EDGE, aLCB);
+
+  // Analyze each loop on closeness and use only closed ones
+  TopTools_DataMapOfShapeShape aDMVCB;
+
+  for (TopTools_ListOfShape::Iterator itLCB(aLCB); itLCB.More(); itLCB.Next())
+  {
+    const TopoDS_Shape& aCB = itLCB.Value();
+
+    TopTools_IndexedDataMapOfShapeListOfShape aDMVE;
+    TopExp::MapShapesAndAncestors(aCB, TopAbs_VERTEX, TopAbs_EDGE, aDMVE);
+    Standard_Boolean isClosed = Standard_True;
+    for (Standard_Integer iV = 1; iV <= aDMVE.Extent(); ++iV)
+    {
+      if (aDMVE(iV).Extent() != 2)
+      {
+        isClosed = Standard_False;
+        break;
+      }
+    }
+    if (!isClosed)
+      continue;
+
+    // Bind loop to each vertex of the loop
+    for (Standard_Integer iV = 1; iV <= aDMVE.Extent(); ++iV)
+    {
+      aDMVCB.Bind(aDMVE.FindKey(iV), aCB);
+    }
+  }
+
+  // Check if any inverted edges of offset faces are locked inside the loops of invalid edges.
+  // Make such edges invalid as well.
+  for (TopTools_ListOfShape::Iterator itLF(theLFOffset); itLF.More(); itLF.Next())
+  {
+    const TopTools_ListOfShape& aLFIm = theFImages.FindFromKey(itLF.Value());
+    for (TopTools_ListOfShape::Iterator itLFIm(aLFIm); itLFIm.More(); itLFIm.Next())
+    {
+      for (TopExp_Explorer expE(itLFIm.Value(), TopAbs_EDGE); expE.More(); expE.Next())
+      {
+        const TopoDS_Edge& aE = TopoDS::Edge(expE.Current());
+        if (!theInvEdges.Contains(aE) && theInvertedEdges.Contains(aE))
+        {
+          const TopoDS_Shape* pCB1 = aDMVCB.Seek (TopExp::FirstVertex(aE));
+          const TopoDS_Shape* pCB2 = aDMVCB.Seek (TopExp::LastVertex(aE));
+          if (pCB1 && pCB2 && pCB1->IsSame(*pCB2))
+          {
+            theInvEdges.Add(aE);
+          }
+        }
+      }
+    }
+  }
+}
+
 //=======================================================================
 //function : FindInvalidFaces
 //purpose  : Looking for the invalid faces by analyzing their invalid edges

src/LDOM/LDOMParser.cxx

@@ -55,13 +55,14 @@ inline
 #endif
         LDOM_XmlReader::RecordType ReadRecord (LDOM_XmlReader&  aReader,
                                                Standard_IStream& theIStream,
-                                               LDOM_OSStream&   aData)
+                                               LDOM_OSStream&   aData,
+                                               Standard_Boolean& theDocStart)
 {
 #ifdef LDOM_PARSER_TRACE
   static aCounter = 0;
   ++ aCounter;
 #endif
-  const LDOM_XmlReader::RecordType aType = aReader.ReadRecord (theIStream, aData);
+  const LDOM_XmlReader::RecordType aType = aReader.ReadRecord (theIStream, aData, theDocStart);
 #ifdef LDOM_PARSER_TRACE
   static FILE * ff = NULL;
   TCollection_AsciiString aTraceFileName;
@@ -172,11 +173,13 @@ Standard_Boolean LDOMParser::ParseDocument (std::istream& theIStream, const Stan
   Standard_Boolean      isDoctype = Standard_False;
 
   Standard_Boolean      isInsertFictRootElement = Standard_False;
+  Standard_Boolean      aDocStart = Standard_True;
+
 
   for(;;) {
     LDOM_XmlReader::RecordType aType = (theWithoutRoot && !isInsertFictRootElement ?
                                         LDOM_XmlReader::XML_START_ELEMENT : 
-                                        ReadRecord (*myReader, theIStream, myCurrentData));
+                                        ReadRecord (*myReader, theIStream, myCurrentData, aDocStart));
     switch (aType) {
     case LDOM_XmlReader::XML_HEADER:
       if (isDoctype || isElement) {
@@ -234,7 +237,7 @@ Standard_Boolean LDOMParser::ParseDocument (std::istream& theIStream, const Stan
           myError = "User abort at startElement()";
           break;
         }
-        isError = ParseElement (theIStream);
+        isError = ParseElement (theIStream, aDocStart);
         if (isError) break;
         continue;
       }
@@ -266,7 +269,7 @@ Standard_Boolean LDOMParser::ParseDocument (std::istream& theIStream, const Stan
 //purpose  : parse one element, given the type of its XML presentation
 //=======================================================================
 
-Standard_Boolean LDOMParser::ParseElement (Standard_IStream& theIStream)
+Standard_Boolean LDOMParser::ParseElement (Standard_IStream& theIStream, Standard_Boolean& theDocStart)
 {
   Standard_Boolean  isError = Standard_False;
   const LDOM_BasicElement * aParent = &myReader->GetElement();
@@ -275,7 +278,7 @@ Standard_Boolean LDOMParser::ParseElement (Standard_IStream& theIStream)
     LDOM_Node::NodeType aLocType;
     LDOMBasicString     aTextValue;
     char *aTextStr;
-    LDOM_XmlReader::RecordType aType = ReadRecord (* myReader, theIStream, myCurrentData);
+    LDOM_XmlReader::RecordType aType = ReadRecord (* myReader, theIStream, myCurrentData, theDocStart);
     switch (aType) {
     case LDOM_XmlReader::XML_UNKNOWN:
       isError = Standard_True;
@@ -300,7 +303,7 @@ Standard_Boolean LDOMParser::ParseElement (Standard_IStream& theIStream)
         myError = "User abort at startElement()";
         break;
       }
-      isError = ParseElement (theIStream);
+      isError = ParseElement (theIStream, theDocStart);
       break;
     case LDOM_XmlReader::XML_END_ELEMENT:
       {

src/LDOM/LDOMParser.hxx

@@ -86,7 +86,7 @@ class LDOMParser
   // ---------- PRIVATE METHODS ----------
   Standard_Boolean      ParseDocument   (Standard_IStream& theIStream, const Standard_Boolean theWithoutRoot = Standard_False);
 
-  Standard_Boolean      ParseElement    (Standard_IStream& theIStream);
+  Standard_Boolean      ParseElement    (Standard_IStream& theIStream, Standard_Boolean& theDocStart);
 
   // ---------- PRIVATE (PROHIBITED) METHODS ----------
 

src/LDOM/LDOM_XmlReader.cxx

@@ -84,7 +84,8 @@ LDOM_XmlReader::LDOM_XmlReader (
 //=======================================================================
 
 LDOM_XmlReader::RecordType LDOM_XmlReader::ReadRecord (Standard_IStream& theIStream,
-                                        LDOM_OSStream& theData)
+                                                       LDOM_OSStream& theData,
+                                                       Standard_Boolean& theDocStart)
 {
   theData.Clear();
   myError.Clear();
@@ -93,7 +94,6 @@ LDOM_XmlReader::RecordType LDOM_XmlReader::ReadRecord (Standard_IStream& theIStr
   LDOMBasicString anAttrName, anAttrValue;
   char anAttDelimiter = '\0';
   Standard_Boolean aHasRead = Standard_False;
-  Standard_Boolean isFileStart = !myEOF && theIStream.tellg() == std::iostream::pos_type(0);
 
   for(;;) {
     //  Check if the current file buffer is exhausted
@@ -155,9 +155,9 @@ LDOM_XmlReader::RecordType LDOM_XmlReader::ReadRecord (Standard_IStream& theIStr
         myBuffer[aBytesRest + aNBytes] = '\0';
       }
     }
-    if (isFileStart)
+    if (theDocStart && !myEOF)
     {
-      isFileStart = Standard_False;
+      theDocStart = Standard_False;
       // check for BOM block
       Standard_Utf8UChar aFirstChar = Standard_Utf8UChar(myPtr[0]);
       switch(aFirstChar) {

src/LDOM/LDOM_XmlReader.hxx

@@ -53,17 +53,19 @@ class LDOM_XmlReader
   // Constructor - takes a file descriptor for input
   // Constructor - takes an std::istream for input
 
-  RecordType            ReadRecord      (Standard_IStream& theIStream, LDOM_OSStream& theData);
+  RecordType ReadRecord (Standard_IStream& theIStream,
+                         LDOM_OSStream& theData,
+                         Standard_Boolean& theDocStart);
   // reading a markup or other element of XML format
 
-  LDOM_BasicElement&    GetElement      () const        { return * myElement; }
+  LDOM_BasicElement& GetElement() const { return * myElement; }
   // get the last element retrieved from the stream
 
   void CreateElement (const char *theName, const Standard_Integer theLen);
 
-  static Standard_Boolean getInteger    (LDOMBasicString&       theValue,
+  static Standard_Boolean getInteger (LDOMBasicString&       theValue,
-                                         const char             * theStart,
+                                      const char             * theStart,
-                                         const char             * theEnd);
+                                      const char             * theEnd);
   // try convert string theStart to LDOM_AsciiInteger, return False on success
 
   // Returns the byte order mask defined at the start of a stream

tests/offset/shape_type_i_c/XY1

@@ -0,0 +1,34 @@
+puts "============================================================================================="
+puts "0032088: Modeling Algorithms - Empty result of offset operation in mode \"Complete\" join type \"Intersection\""
+puts "============================================================================================="
+puts ""
+
+restore [locate_data_file bug32088_trimmed.brep] s
+
+set ref_values { { 23829.6 171246      13 13 } \
+                 { 25781.5 196049      14 14 } \
+                 { 27762.8 222816      14 14 } \
+                 { 29808.5 251596      12 12 } \
+                 { 31919.5 282455      12 12 } \
+                 { 34088.4 315454      12 12 } \
+                 { 36315.3 350651      12 12 } \
+                 { 38600   388104      12 12 } \
+                 { 40942.8 427870      12 12 } \
+                 { 43343.5 470009      12 12 } \
+                 { 45802.1 514577      12 12 } \
+                 { 48318.6 561632      12 12 } \
+                 { 50893.1 611233      12 12 } \
+                 { 53525.6 663438      12 12 } \
+                 { 56215.9 718304      12 12 } \
+                 { 58964.3 775889      12 12 } \
+                 { 61770.5 836251      12 12 } \
+                 { 64634.7 899449      12 12 } \
+                 { 67556.9 965540      12 12 } \
+                 { 70537   1.03458e+06 12 12 } }
+
+perform_offset_increasing s 1 20 1 $ref_values
+
+copy r5 result
+copy r5_unif result_unif
+
+checkview -display result_unif -2d -path ${imagedir}/${test_image}.png

tests/offset/shape_type_i_c/XY2

@@ -0,0 +1,17 @@
+puts "============================================================================================="
+puts "0032088: Modeling Algorithms - Empty result of offset operation in mode \"Complete\" join type \"Intersection\""
+puts "============================================================================================="
+puts ""
+
+restore [locate_data_file bug32088_input.brep] s
+
+offsetparameter 1e-7 c i r
+offsetload s 5
+offsetperform result
+
+checkprops result -s 3.47344e+06 -v 4.06389e+07
+
+unifysamedom result_unif result
+checknbshapes result_unif -wire 962 -face 962 -shell 1 -solid 1
+
+checkview -display result_unif -2d -path ${imagedir}/${test_image}.png

tests/offset/shape_type_i_c/XY3

@@ -0,0 +1,17 @@
+puts "============================================================================================="
+puts "0032088: Modeling Algorithms - Empty result of offset operation in mode \"Complete\" join type \"Intersection\""
+puts "============================================================================================="
+puts ""
+
+restore [locate_data_file bug32088_input.brep] s
+
+offsetparameter 1e-7 c i r
+offsetload s 8
+offsetperform result
+
+checkprops result -s 3.35577e+06 -v 5.12413e+07
+
+unifysamedom result_unif result
+checknbshapes result_unif -wire 755 -face 755 -shell 1 -solid 1
+
+checkview -display result_unif -2d -path ${imagedir}/${test_image}.png

tests/offset/shape_type_i_c/XY4

@@ -0,0 +1,17 @@
+puts "============================================================================================="
+puts "0032088: Modeling Algorithms - Empty result of offset operation in mode \"Complete\" join type \"Intersection\""
+puts "============================================================================================="
+puts ""
+
+restore [locate_data_file bug32088_input.brep] s
+
+offsetparameter 1e-7 c i r
+offsetload s 10
+offsetperform result
+
+checkprops result -s 3.1312e+06 -v 5.77267e+07
+
+unifysamedom result_unif result
+checknbshapes result_unif -wire 492 -face 492 -shell 1 -solid 1
+
+checkview -display result_unif -2d -path ${imagedir}/${test_image}.png

tests/offset/shape_type_i_c/XY5

@@ -0,0 +1,17 @@
+puts "============================================================================================="
+puts "0032088: Modeling Algorithms - Empty result of offset operation in mode \"Complete\" join type \"Intersection\""
+puts "============================================================================================="
+puts ""
+
+restore [locate_data_file bug32088_input.brep] s
+
+offsetparameter 1e-7 c i r
+offsetload s 11
+offsetperform result
+
+checkprops result -s 2.75287e+06 -v 6.08747e+07
+
+unifysamedom result_unif result
+checknbshapes result_unif -wire 234 -face 234 -shell 1 -solid 1
+
+checkview -display result_unif -2d -path ${imagedir}/${test_image}.png

tests/offset/shape_type_i_c/XY6

@@ -0,0 +1,17 @@
+puts "============================================================================================="
+puts "0032088: Modeling Algorithms - Empty result of offset operation in mode \"Complete\" join type \"Intersection\""
+puts "============================================================================================="
+puts ""
+
+restore [locate_data_file bug32088_input.brep] s
+
+offsetparameter 1e-7 c i r
+offsetload s 13
+offsetperform result
+
+checkprops result -s 2.84681e+06 -v 6.64723e+07
+
+unifysamedom result_unif result
+checknbshapes result_unif -wire 234 -face 234 -shell 1 -solid 1
+
+checkview -display result_unif -2d -path ${imagedir}/${test_image}.png

tests/offset/shape_type_i_c/XY7

@@ -0,0 +1,17 @@
+puts "============================================================================================="
+puts "0032088: Modeling Algorithms - Empty result of offset operation in mode \"Complete\" join type \"Intersection\""
+puts "============================================================================================="
+puts ""
+
+restore [locate_data_file bug32088_input.brep] s
+
+offsetparameter 1e-7 c i r
+offsetload s 15
+offsetperform result
+
+checkprops result -s 2.7281e+06 -v 7.20465e+07
+
+unifysamedom result_unif result
+checknbshapes result_unif -wire 104 -face 104 -shell 1 -solid 1
+
+checkview -display result_unif -2d -path ${imagedir}/${test_image}.png

tests/offset/shape_type_i_c/XZ1

@@ -0,0 +1,17 @@
+puts "============================================================================================="
+puts "0032307: Modeling Algorithms - Empty result of offset operation in mode \"Complete\" Joint type \"Intersection\""
+puts "============================================================================================="
+puts ""
+
+restore [locate_data_file bug32307.brep] s
+
+offsetparameter 1e-7 c i r
+offsetload s 20
+offsetperform result
+
+checkprops result -s 1.29992e+07 -v 8.09132e+08
+
+# number of shapes should not change
+checknbshapes result -ref [nbshapes s]
+
+checkview -display result -2d -path ${imagedir}/${test_image}.png

tests/offset/shape_type_i_c/XZ2

@@ -0,0 +1,24 @@
+puts "============================================================================================="
+puts "0032307: Modeling Algorithms - Empty result of offset operation in mode \"Complete\" Joint type \"Intersection\""
+puts "============================================================================================="
+puts ""
+
+restore [locate_data_file bug32307.brep] s
+
+offsetparameter 1e-7 c i r
+offsetload s 0
+foreach f [explode s f] {
+  mksurface surf $f
+  regexp {Axis   :([-0-9.+eE]*), ([-0-9.+eE]*), ([-0-9.+eE]*)} [dump surf] full x y z
+  if {abs($z) > 1.e-7 || (abs($y) < 1.e-7 && abs($x) > 1.e-7)} {
+    offsetonface $f 20
+  }
+}
+offsetperform result
+
+checkprops result -s 1.20298e+07 -v 7.1394e+08
+
+# number of shapes should not change
+checknbshapes result -ref [nbshapes s]
+
+checkview -display result -2d -path ${imagedir}/${test_image}.png