0031251: Add a new meshing parameter to enforce face linear deflection

Parameter has been renamed to ForceFaceDeflection. Added test case.

New parameter -force_face_def has been added to incmesh command.

src/BRepMesh/BRepMesh_Deflection.cxx

@@ -145,18 +145,22 @@ void BRepMesh_Deflection::ComputeDeflection (
   }
 
   Standard_Real aFaceDeflection = 0.0;
-  if (theDFace->WiresNb () > 0)
+  if (!theParameters.ForceFaceDeflection)
   {
-    for (Standard_Integer aWireIt = 0; aWireIt < theDFace->WiresNb(); ++aWireIt)
+    if (theDFace->WiresNb () > 0)
     {
-      aFaceDeflection += theDFace->GetWire(aWireIt)->GetDeflection();
+      for (Standard_Integer aWireIt = 0; aWireIt < theDFace->WiresNb (); ++aWireIt)
+      {
+        aFaceDeflection += theDFace->GetWire (aWireIt)->GetDeflection ();
+      }
+
+      aFaceDeflection /= theDFace->WiresNb ();
     }
 
-    aFaceDeflection /= theDFace->WiresNb ();
+    aFaceDeflection = Max (2. * BRepMesh_ShapeTool::MaxFaceTolerance (
+      theDFace->GetFace ()), aFaceDeflection);
   }
+  aFaceDeflection = Max (aDeflection, aFaceDeflection);
 
-  aFaceDeflection = Max(aDeflection, aFaceDeflection);
+  theDFace->SetDeflection (aFaceDeflection);
-
-  theDFace->SetDeflection (Max(2.* BRepMesh_ShapeTool::MaxFaceTolerance(
-    theDFace->GetFace()), aFaceDeflection));
 }

src/BRepMesh/BRepMesh_ShapeTool.cxx

@@ -72,7 +72,7 @@ Standard_Real BRepMesh_ShapeTool::MaxFaceTolerance(const TopoDS_Face& theFace)
   Standard_Real aMaxTolerance = BRep_Tool::Tolerance(theFace);
 
   Standard_Real aTolerance = Max(
-    MaxTolerance<TopAbs_EDGE, EdgeTolerance  >(theFace),
+    MaxTolerance<TopAbs_EDGE,   EdgeTolerance  >(theFace),
     MaxTolerance<TopAbs_VERTEX, VertexTolerance>(theFace));
 
   return Max(aMaxTolerance, aTolerance);

src/IMeshTools/IMeshTools_Parameters.hxx

@@ -34,7 +34,8 @@ struct IMeshTools_Parameters {
     InternalVerticesMode (Standard_True),
     ControlSurfaceDeflection (Standard_True),
     CleanModel (Standard_True),
-    AdjustMinSize (Standard_False)
+    AdjustMinSize (Standard_False),
+    ForceFaceDeflection (Standard_False)
   {
   }
 
@@ -83,6 +84,10 @@ struct IMeshTools_Parameters {
   //! Enables/disables local adjustment of min size depending on edge size.
   //! Disabled by default.
   Standard_Boolean                                 AdjustMinSize;
+
+  //! Enables/disables usage of shape tolerances for computing face deflection.
+  //! Disabled by default.
+  Standard_Boolean                                 ForceFaceDeflection;
 };
 
 #endif

src/MeshTest/MeshTest.cxx

@@ -88,7 +88,8 @@ options:\n\
         -surf_def_off   disables control of deflection of mesh from real\n\
                         surface (enabled by default)\n\
         -parallel       enables parallel execution (switched off by default)\n\
-        -adjust_min     enables local adjustment of min size depending on edge size (switched off by default)\n";
+        -adjust_min     enables local adjustment of min size depending on edge size (switched off by default)\n\
+        -force_face_def disables usage of shape tolerances for computing face deflection (switched off by default). \n";
     return 0;
   }
 
@@ -123,6 +124,8 @@ options:\n\
         aMeshParams.ControlSurfaceDeflection = Standard_False;
       else if (aOpt == "-adjust_min")
         aMeshParams.AdjustMinSize = Standard_True;
+      else if (aOpt == "-force_face_def")
+        aMeshParams.ForceFaceDeflection = Standard_True;
       else if (i < nbarg)
       {
         Standard_Real aVal = Draw::Atof(argv[i++]);

tests/bugs/mesh/bug31251

@@ -0,0 +1,30 @@
+puts "======="
+puts "0031251: Mesh - Add a parameter for IncrementalMesh to ignore face tolerance for face deflection"
+puts "======="
+puts ""
+
+pload XDE
+
+stepread [locate_data_file bug31251_Albatros_d2_elisa_a.STEP] a *
+renamevar a_1 result
+
+vinit
+vtop
+vsetdispmode 1
+vdefaults -autoTriang 0
+
+tclean result
+incmesh result 0.004 -a 14
+checktrinfo result -tri 70560 -nod 39946 -defl 0.22962869401103247
+
+vdisplay result -redisplay
+vfit
+checkview -screenshot -3d -path ${imagedir}/${test_image}_default.png
+
+tclean result
+incmesh result 0.004 -a 14 -force_face_def
+checktrinfo result -tri 292560 -nod 150946 -defl 0.04579460790575135
+
+vdisplay result -redisplay
+vfit
+checkview -screenshot -3d -path ${imagedir}/${test_image}_tightfit.png