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0028211: Modeling Algorithms - Boolean fuse operation produces incorrect result

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Correct procedure of initialization of BRepTopAdaptor_FClass2d and IntTools_FClass2d classifiers so as to produce more tight polygon in the case of self-intersections on very thin faces.

The idea is concluded in checking the condition:
defl < 2 * S / P, where S - is the surface area computed on produced polygon, P - its perimeter, defl - deflection computed on it.
If the condition is not true the polygon is discretized again using QuasiUniformDeflection tool.
This commit is contained in:
msv
2017-12-29 17:44:42 +03:00
committed by apn
parent 67b3d2a8ad
commit 2651bb324e
5 changed files with 246 additions and 6 deletions
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79
src/BRepTopAdaptor/BRepTopAdaptor_FClass2d.cxx
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@@ -30,6 +30,7 @@
#include <ElCLib.hxx>
#include <Geom2dInt_Geom2dCurveTool.hxx>
#include <GeomAbs_SurfaceType.hxx>
#include <GCPnts_QuasiUniformDeflection.hxx>
#include <gp_Pnt.hxx>
#include <gp_Pnt2d.hxx>
#include <Precision.hxx>
@@ -298,7 +299,7 @@ BRepTopAdaptor_FClass2d::BRepTopAdaptor_FClass2d(const TopoDS_Face& aFace,const
PClass(im1)=SeqPnt2d.Value(im1);
PClass(nbpnts)=SeqPnt2d.Value(nbpnts);
Standard_Real aPer = 0.;
// for(Standard_Integer ii=1; ii<nbpnts; ii++,im0++,im1++,im2++)
for(Standard_Integer ii=1; ii<nbpnts; ii++,im0++,im1++)
{
@@ -310,10 +311,86 @@ BRepTopAdaptor_FClass2d::BRepTopAdaptor_FClass2d(const TopoDS_Face& aFace,const
// Standard_Real N = A.Magnitude() * B.Magnitude();
square += (PClass(im0).X()-PClass(im1).X())*(PClass(im0).Y()+PClass(im1).Y())*.5;
aPer += (PClass(im0).XY() - PClass(im1).XY()).Modulus();
// if(N>1e-16){ Standard_Real a=A.Angle(B); angle+=a; }
}
Standard_Real anExpThick = Max(2. * Abs(square) / aPer, 1e-7);
Standard_Real aDefl = Max(FlecheU, FlecheV);
Standard_Real aDiscrDefl = Min(aDefl*0.1, anExpThick * 10.);
while (aDefl > anExpThick && aDiscrDefl > 1e-7)
{
// Deflection of the polygon is too much for this ratio of area and perimeter,
// and this might lead to self-intersections.
// Discretize the wire more tightly to eliminate the error.
firstpoint = 1;
SeqPnt2d.Clear();
FlecheU = 0.0;
FlecheV = 0.0;
for (WireExplorer.Init(TopoDS::Wire(FaceExplorer.Current()), Face);
WireExplorer.More(); WireExplorer.Next())
{
edge = WireExplorer.Current();
Or = edge.Orientation();
if (Or == TopAbs_FORWARD || Or == TopAbs_REVERSED)
{
Standard_Real pfbid, plbid;
BRep_Tool::Range(edge, Face, pfbid, plbid);
if (Abs(plbid - pfbid) < 1.e-9) continue;
BRepAdaptor_Curve2d C(edge, Face);
GCPnts_QuasiUniformDeflection aDiscr(C, aDiscrDefl);
if (!aDiscr.IsDone())
break;
Standard_Integer nbp = aDiscr.NbPoints();
Standard_Integer iStep = 1, i = 1, iEnd = nbp + 1;
if (Or == TopAbs_REVERSED)
{
iStep = -1;
i = nbp;
iEnd = 0;
}
if (firstpoint == 2)
i += iStep;
for (; i != iEnd; i += iStep)
{
gp_Pnt2d aP2d = C.Value(aDiscr.Parameter(i));
SeqPnt2d.Append(aP2d);
}
if (nbp > 2)
{
Standard_Integer ii = SeqPnt2d.Length();
gp_Lin2d Lin(SeqPnt2d(ii - 2), gp_Dir2d(gp_Vec2d(SeqPnt2d(ii - 2), SeqPnt2d(ii))));
Standard_Real ul = ElCLib::Parameter(Lin, SeqPnt2d(ii - 1));
gp_Pnt2d Pp = ElCLib::Value(ul, Lin);
Standard_Real dU = Abs(Pp.X() - SeqPnt2d(ii - 1).X());
Standard_Real dV = Abs(Pp.Y() - SeqPnt2d(ii - 1).Y());
if (dU > FlecheU) FlecheU = dU;
if (dV > FlecheV) FlecheV = dV;
}
firstpoint = 2;
}
}
nbpnts = SeqPnt2d.Length();
PClass.Resize(1, nbpnts, Standard_False);
im1 = nbpnts - 1;
im0 = 1;
PClass(im1) = SeqPnt2d.Value(im1);
PClass(nbpnts) = SeqPnt2d.Value(nbpnts);
square = 0.;
aPer = 0.;
for (Standard_Integer ii = 1; ii<nbpnts; ii++, im0++, im1++)
{
if (im1 >= nbpnts) im1 = 1;
PClass(ii) = SeqPnt2d.Value(ii);
square += (PClass(im0).X() - PClass(im1).X())*(PClass(im0).Y() + PClass(im1).Y())*.5;
aPer += (PClass(im0).XY() - PClass(im1).XY()).Modulus();
}
anExpThick = Max(2. * Abs(square) / aPer, 1e-7);
aDefl = Max(FlecheU, FlecheV);
aDiscrDefl = Min(aDiscrDefl * 0.1, anExpThick * 10.);
}
//-- FlecheU*=10.0;
//-- FlecheV*=10.0;