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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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114
src/IntTools/IntTools_FClass2d.cxx
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@@ -26,6 +26,7 @@
#include <Geom2dInt_Geom2dCurveTool.hxx>
#include <GeomAbs_SurfaceType.hxx>
#include <GeomInt.hxx>
#include <GCPnts_QuasiUniformDeflection.hxx>
#include <gp_Pnt.hxx>
#include <gp_Pnt2d.hxx>
#include <IntTools_FClass2d.hxx>
@@ -44,6 +45,13 @@
#include <TopoDS_Wire.hxx>
#include <stdio.h>
//#define DEBUG_PCLASS_POLYGON
#ifdef DEBUG_PCLASS_POLYGON
#include <DrawTrSurf.hxx>
#include <Geom2d_BSplineCurve.hxx>
#endif
//=======================================================================
//function : IntTools_FClass2d:IntTools:_FClass2d
//purpose :
@@ -386,7 +394,6 @@ void IntTools_FClass2d::Init(const TopoDS_Face& aFace,
Standard_Integer im2=nbpnts-2;
Standard_Integer im1=nbpnts-1;
Standard_Integer im0=1;
Standard_Integer ii;
Standard_Real angle = 0.0;
Standard_Real aX0, aY0, aX1, aY1, aS;
//
@@ -397,7 +404,9 @@ void IntTools_FClass2d::Init(const TopoDS_Face& aFace,
PClass(im2)=SeqPnt2d.Value(im2);
PClass(im1)=SeqPnt2d.Value(im1);
PClass(nbpnts)=SeqPnt2d.Value(nbpnts);
for(ii=1; ii<nbpnts; ii++,im0++,im1++,im2++) {
Standard_Real aPer = 0.;
for (Standard_Integer ii = 1; ii<nbpnts; ii++, im0++, im1++, im2++)
{
if(im2>=nbpnts) im2=1;
if(im1>=nbpnts) im1=1;
PClass(ii)=SeqPnt2d.Value(ii);
@@ -408,6 +417,7 @@ void IntTools_FClass2d::Init(const TopoDS_Face& aFace,
aP2D0.Coord(aX0, aY0);
aP2D1.Coord(aX1, aY1);
aS=aS+(aY0+aY1)*(aX1-aX0);
aPer += aP2D1.Distance(aP2D0);
gp_Vec2d A(PClass(im2),PClass(im1));
gp_Vec2d B(PClass(im1),PClass(im0));
@@ -455,6 +465,106 @@ void IntTools_FClass2d::Init(const TopoDS_Face& aFace,
if (!iFlag) {
angle = 0.;
}
#ifdef DEBUG_PCLASS_POLYGON
TColStd_Array1OfReal aKnots(1, nbpnts);
TColStd_Array1OfInteger aMults(1, nbpnts);
for (int i = 1; i <= nbpnts; i++)
{
aKnots(i) = i;
aMults(i) = 1;
}
aMults(1) = aMults(nbpnts) = 2;
Handle(Geom2d_BSplineCurve) aPol = new Geom2d_BSplineCurve(PClass, aKnots, aMults, 1);
DrawTrSurf::Set("pol", aPol);
#endif
Standard_Real anExpThick = Max(2. * Abs(aS) / 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 (aWExp.Init(TopoDS::Wire(aExpF.Current()), Face);
aWExp.More(); aWExp.Next())
{
edge = aWExp.Current();
Or = edge.Orientation();
if (Or == TopAbs_FORWARD || Or == TopAbs_REVERSED)
{
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);
aS = 0.;
aPer = 0.;
for (Standard_Integer ii = 1; ii<nbpnts; ii++, im0++, im1++)
{
if (im1 >= nbpnts) im1 = 1;
PClass(ii) = SeqPnt2d.Value(ii);
aS += (PClass(im1).X() - PClass(im0).X())*(PClass(im0).Y() + PClass(im1).Y())*.5;
aPer += (PClass(im0).XY() - PClass(im1).XY()).Modulus();
}
#ifdef DEBUG_PCLASS_POLYGON
TColStd_Array1OfReal aKnots(1, nbpnts);
TColStd_Array1OfInteger aMults(1, nbpnts);
for (int i = 1; i <= nbpnts; i++)
{
aKnots(i) = i;
aMults(i) = 1;
}
aMults(1) = aMults(nbpnts) = 2;
Handle(Geom2d_BSplineCurve) aPol = new Geom2d_BSplineCurve(PClass, aKnots, aMults, 1);
DrawTrSurf::Set("pol1", aPol);
#endif
anExpThick = Max(2. * Abs(aS) / aPer, 1e-7);
aDefl = Max(FlecheU, FlecheV);
aDiscrDefl = Min(aDiscrDefl * 0.1, anExpThick * 10.);
}
if(aS>0.){
myIsHole=Standard_False;
}