netgen/libsrc/meshing/smoothing2.cpp
2011-10-12 20:57:49 +00:00

904 lines
20 KiB
C++

#include <mystdlib.h>
#include "meshing.hpp"
#include <opti.hpp>
namespace netgen
{
static const double c_trig = 0.14433756; // sqrt(3.0) / 12
static const double c_trig4 = 0.57735026; // sqrt(3.0) / 3
inline double CalcTriangleBadness (double x2, double x3, double y3,
double metricweight, double h)
{
// badness = sqrt(3.0) / 12 * (\sum l_i^2) / area - 1
// p1 = (0, 0), p2 = (x2, 0), p3 = (x3, y3);
double cir_2 = (x2*x2 + x3*x3 + y3*y3 - x2*x3);
double area = x2 * y3;
if (area <= 1e-24 * cir_2)
return 1e10;
double badness = c_trig4 * cir_2 / area - 1;
if (metricweight > 0)
{
// add: metricweight * (area / h^2 + h^2 / area - 2)
double areahh = area / (h * h);
badness += metricweight * (areahh + 1 / areahh - 2);
}
return badness;
}
inline void CalcTriangleBadness (double x2, double x3, double y3, double metricweight,
double h, double & badness, double & g1x, double & g1y)
{
// old: badness = sqrt(3.0) /36 * circumference^2 / area - 1
// badness = sqrt(3.0) / 12 * (\sum l_i^2) / area - 1
// p1 = (0, 0), p2 = (x2, 0), p3 = (x3, y3);
double cir_2 = 2* (x2*x2 + x3*x3 + y3*y3 - x2*x3);
double area = 0.5 * x2 * y3;
if (area <= 1e-24 * cir_2)
{
g1x = 0;
g1y = 0;
badness = 1e10;
return;
}
badness = c_trig * cir_2 / area - 1;
double c1 = -2 * c_trig / area;
double c2 = 0.5 * c_trig * cir_2 / (area * area);
g1x = c1 * (x2 + x3) + c2 * y3;
g1y = c1 * (y3) + c2 * (x2-x3);
if (metricweight > 0)
{
// area = (x2 - x1) * (y3 - y1) - (x3 - x1) * (y2 - y1);
// add: metricweight * (area / h^2 + h^2 / area - 2)
area = x2 * y3;
double dareax1 = -y3;
double dareay1 = x3 - x2;
double areahh = area / (h * h);
double fac = metricweight * (areahh - 1 / areahh) / area;
badness += metricweight * (areahh + 1 / areahh - 2);
g1x += fac * dareax1;
g1y += fac * dareay1;
}
}
double CalcTriangleBadness (const Point3d & p1,
const Point3d & p2,
const Point3d & p3,
double metricweight,
double h)
{
// badness = sqrt(3.0) / 12 * (\sum l_i^2) / area - 1
// p1 = (0, 0), p2 = (x2, 0), p3 = (x3, y3);
Vec3d e12(p1,p2);
Vec3d e13(p1,p3);
Vec3d e23(p2,p3);
double l12_2 = e12.Length2();
double l13_2 = e13.Length2();
double l23_2 = e23.Length2();
double cir_2 = l12_2 + l13_2 + l23_2;
Vec3d area_v = Cross (e12, e13);
double area = 0.5 * area_v.Length();
if (area <= 1e-24 * cir_2)
return 1e10;
double badness = c_trig * cir_2 / area - 1;
if (metricweight > 0)
{
// area = (x2 - x1) * (y3 - y1) - (x3 - x1) * (y2 - y1);
// add: metricweight * (area / h^2 + h^2 / area - 2)
const double areahh = area / (h * h);
badness += metricweight * (areahh + 1 / areahh - 2);
}
return badness;
}
double CalcTriangleBadness (const Point3d & p1,
const Point3d & p2,
const Point3d & p3,
const Vec3d & n,
double metricweight,
double h)
{
Vec3d v1 (p1, p2);
Vec3d v2 (p1, p3);
Vec3d e1 = v1;
Vec3d e2 = v2;
e1 -= (e1 * n) * n;
e1 /= (e1.Length() + 1e-24);
e2 = Cross (n, e1);
return CalcTriangleBadness ( (e1 * v1), (e1 * v2), (e2 * v2),
metricweight, h);
}
class Opti2dLocalData
{
public:
const MeshOptimize2d * meshthis;
MeshPoint sp1;
PointGeomInfo gi1;
Vec<3> normal, t1, t2;
Array<SurfaceElementIndex> locelements;
Array<int> locrots;
Array<double> lochs;
// static int locerr2;
double locmetricweight;
double loch;
int surfi, surfi2;
int uselocalh;
public:
Opti2dLocalData ()
{
locmetricweight = 0;
}
};
class Opti2SurfaceMinFunction : public MinFunction
{
const Mesh & mesh;
Opti2dLocalData & ld;
public:
Opti2SurfaceMinFunction (const Mesh & amesh,
Opti2dLocalData & ald)
: mesh(amesh), ld(ald)
{ } ;
virtual double FuncGrad (const Vector & x, Vector & g) const;
virtual double FuncDeriv (const Vector & x, const Vector & dir, double & deriv) const;
virtual double Func (const Vector & x) const;
};
double Opti2SurfaceMinFunction ::
Func (const Vector & x) const
{
Vector g(x.Size());
return FuncGrad (x, g);
}
double Opti2SurfaceMinFunction ::
FuncGrad (const Vector & x, Vector & grad) const
{
Vec<3> n, vgrad;
Point<3> pp1;
double g1x, g1y;
double badness, hbadness;
vgrad = 0;
badness = 0;
ld.meshthis -> GetNormalVector (ld.surfi, ld.sp1, ld.gi1, n);
pp1 = ld.sp1 + x(0) * ld.t1 + x(1) * ld.t2;
// meshthis -> ProjectPoint (surfi, pp1);
// meshthis -> GetNormalVector (surfi, pp1, n);
for (int j = 0; j < ld.locelements.Size(); j++)
{
int roti = ld.locrots[j];
const Element2d & bel = mesh[ld.locelements[j]];
Vec<3> e1 = mesh[bel.PNumMod(roti + 1)] - pp1;
Vec<3> e2 = mesh[bel.PNumMod(roti + 2)] - pp1;
if (ld.uselocalh) ld.loch = ld.lochs[j];
double e1l = e1.Length();
if (Determinant(e1, e2, n) > 1e-8 * e1l * e2.Length())
{
e1 /= e1l;
double e1e2 = e1 * e2;
e2 -= e1e2 * e1;
double e2l = e2.Length();
CalcTriangleBadness ( e1l, e1e2, e2l, ld.locmetricweight, ld.loch,
hbadness, g1x, g1y);
badness += hbadness;
vgrad += g1x * e1 + (g1y/e2l) * e2;
}
else
{
// (*testout) << "very very bad badness" << endl;
badness += 1e8;
}
}
vgrad -= (vgrad * n) * n;
grad(0) = vgrad * ld.t1;
grad(1) = vgrad * ld.t2;
return badness;
}
double Opti2SurfaceMinFunction ::
FuncDeriv (const Vector & x, const Vector & dir, double & deriv) const
{
Vec<3> n, vgrad;
Point<3> pp1;
double g1x, g1y;
double badness, hbadness;
vgrad = 0;
badness = 0;
ld.meshthis -> GetNormalVector (ld.surfi, ld.sp1, ld.gi1, n);
pp1 = ld.sp1 + x(0) * ld.t1 + x(1) * ld.t2;
for (int j = 0; j < ld.locelements.Size(); j++)
{
int roti = ld.locrots[j];
const Element2d & bel = mesh[ld.locelements[j]];
Vec<3> e1 = mesh[bel.PNumMod(roti + 1)] - pp1;
Vec<3> e2 = mesh[bel.PNumMod(roti + 2)] - pp1;
if (ld.uselocalh) ld.loch = ld.lochs[j];
double e1l = e1.Length();
if (Determinant(e1, e2, n) > 1e-8 * e1l * e2.Length())
{
e1 /= e1l;
double e1e2 = e1 * e2;
e2 -= e1e2 * e1;
double e2l = e2.Length();
CalcTriangleBadness ( e1l, e1e2, e2l, ld.locmetricweight, ld.loch,
hbadness, g1x, g1y);
badness += hbadness;
vgrad += g1x * e1 + (g1y / e2l) * e2;
}
else
{
// (*testout) << "very very bad badness" << endl;
badness += 1e8;
}
}
vgrad -= (vgrad * n) * n;
deriv = dir(0) * (vgrad*ld.t1) + dir(1) * (vgrad*ld.t2);
return badness;
}
class Opti2EdgeMinFunction : public MinFunction
{
const Mesh & mesh;
Opti2dLocalData & ld;
public:
Opti2EdgeMinFunction (const Mesh & amesh,
Opti2dLocalData & ald)
: mesh(amesh), ld(ald) { } ;
virtual double FuncGrad (const Vector & x, Vector & g) const;
virtual double Func (const Vector & x) const;
};
double Opti2EdgeMinFunction :: Func (const Vector & x) const
{
Vector g(x.Size());
return FuncGrad (x, g);
}
double Opti2EdgeMinFunction :: FuncGrad (const Vector & x, Vector & grad) const
{
int j, rot;
Vec<3> n1, n2, v1, v2, e1, e2, vgrad;
Point<3> pp1;
Vec<2> g1;
double badness, hbadness;
vgrad = 0.0;
badness = 0;
pp1 = ld.sp1 + x(0) * ld.t1;
ld.meshthis -> ProjectPoint2 (ld.surfi, ld.surfi2, pp1);
for (j = 0; j < ld.locelements.Size(); j++)
{
rot = ld.locrots[j];
const Element2d & bel = mesh[ld.locelements[j]];
v1 = mesh[bel.PNumMod(rot + 1)] - pp1;
v2 = mesh[bel.PNumMod(rot + 2)] - pp1;
e1 = v1;
e2 = v2;
e1 /= e1.Length();
e2 -= (e1 * e2) * e1;
e2 /= e2.Length();
if (ld.uselocalh) ld.loch = ld.lochs[j];
CalcTriangleBadness ( (e1 * v1), (e1 * v2), (e2 * v2), ld.locmetricweight, ld.loch,
hbadness, g1(0), g1(1));
badness += hbadness;
vgrad += g1(0) * e1 + g1(1) * e2;
}
ld.meshthis -> GetNormalVector (ld.surfi, pp1, n1);
ld.meshthis -> GetNormalVector (ld.surfi2, pp1, n2);
v1 = Cross (n1, n2);
v1.Normalize();
grad(0) = (vgrad * v1) * (ld.t1 * v1);
return badness;
}
class Opti2SurfaceMinFunctionJacobian : public MinFunction
{
const Mesh & mesh;
Opti2dLocalData & ld;
public:
Opti2SurfaceMinFunctionJacobian (const Mesh & amesh,
Opti2dLocalData & ald)
: mesh(amesh), ld(ald)
{ } ;
virtual double FuncGrad (const Vector & x, Vector & g) const;
virtual double FuncDeriv (const Vector & x, const Vector & dir, double & deriv) const;
virtual double Func (const Vector & x) const;
};
double Opti2SurfaceMinFunctionJacobian ::
Func (const Vector & x) const
{
Vector g(x.Size());
return FuncGrad (x, g);
}
double Opti2SurfaceMinFunctionJacobian ::
FuncGrad (const Vector & x, Vector & grad) const
{
// from 2d:
int lpi, gpi;
Vec<3> n, vgrad;
Point<3> pp1;
Vec2d g1, vdir;
double badness, hbad, hderiv;
vgrad = 0;
badness = 0;
ld.meshthis -> GetNormalVector (ld.surfi, ld.sp1, ld.gi1, n);
pp1 = ld.sp1 + x(0) * ld.t1 + x(1) * ld.t2;
// meshthis -> ProjectPoint (surfi, pp1);
// meshthis -> GetNormalVector (surfi, pp1, n);
static Array<Point2d> pts2d;
pts2d.SetSize(mesh.GetNP());
grad = 0;
for (int j = 1; j <= ld.locelements.Size(); j++)
{
lpi = ld.locrots.Get(j);
const Element2d & bel =
mesh[ld.locelements.Get(j)];
gpi = bel.PNum(lpi);
for (int k = 1; k <= bel.GetNP(); k++)
{
PointIndex pi = bel.PNum(k);
pts2d.Elem(pi) = Point2d (ld.t1 * (mesh.Point(pi) - ld.sp1),
ld.t2 * (mesh.Point(pi) - ld.sp1));
}
pts2d.Elem(gpi) = Point2d (x(0), x(1));
for (int k = 1; k <= 2; k++)
{
if (k == 1)
vdir = Vec2d (1, 0);
else
vdir = Vec2d (0, 1);
hbad = bel.
CalcJacobianBadnessDirDeriv (pts2d, lpi, vdir, hderiv);
grad(k-1) += hderiv;
if (k == 1)
badness += hbad;
}
}
/*
vgrad.Add (-(vgrad * n), n);
grad.Elem(1) = vgrad * t1;
grad.Elem(2) = vgrad * t2;
*/
return badness;
}
double Opti2SurfaceMinFunctionJacobian ::
FuncDeriv (const Vector & x, const Vector & dir, double & deriv) const
{
// from 2d:
int j, k, lpi, gpi;
Vec<3> n, vgrad;
Point<3> pp1;
Vec2d g1, vdir;
double badness, hbad, hderiv;
vgrad = 0;
badness = 0;
ld.meshthis -> GetNormalVector (ld.surfi, ld.sp1, ld.gi1, n);
// pp1 = sp1;
// pp1.Add2 (x.Get(1), t1, x.Get(2), t2);
pp1 = ld.sp1 + x(0) * ld.t1 + x(1) * ld.t2;
static Array<Point2d> pts2d;
pts2d.SetSize(mesh.GetNP());
deriv = 0;
for (j = 1; j <= ld.locelements.Size(); j++)
{
lpi = ld.locrots.Get(j);
const Element2d & bel =
mesh[ld.locelements.Get(j)];
gpi = bel.PNum(lpi);
for (k = 1; k <= bel.GetNP(); k++)
{
PointIndex pi = bel.PNum(k);
pts2d.Elem(pi) = Point2d (ld.t1 * (mesh.Point(pi) - ld.sp1),
ld.t2 * (mesh.Point(pi) - ld.sp1));
}
pts2d.Elem(gpi) = Point2d (x(0), x(1));
vdir = Vec2d (dir(0), dir(1));
hbad = bel.
CalcJacobianBadnessDirDeriv (pts2d, lpi, vdir, hderiv);
deriv += hderiv;
badness += hbad;
}
return badness;
}
MeshOptimize2d dummy;
MeshOptimize2d :: MeshOptimize2d ()
{
SetFaceIndex (0);
SetImproveEdges (0);
SetMetricWeight (0);
SetWriteStatus (1);
}
void MeshOptimize2d :: SelectSurfaceOfPoint (const Point<3> & p,
const PointGeomInfo & gi)
{
;
}
void MeshOptimize2d :: ImproveMesh (Mesh & mesh, const MeshingParameters & mp)
{
if (!faceindex)
{
PrintMessage (3, "Smoothing");
for (faceindex = 1; faceindex <= mesh.GetNFD(); faceindex++)
{
ImproveMesh (mesh, mp);
if (multithread.terminate)
throw NgException ("Meshing stopped");
}
faceindex = 0;
return;
}
static int timer = NgProfiler::CreateTimer ("MeshSmoothing 2D");
static int timer1 = NgProfiler::CreateTimer ("MeshSmoothing 2D start");
NgProfiler::RegionTimer reg (timer);
NgProfiler::StartTimer (timer1);
CheckMeshApproximation (mesh);
Opti2dLocalData ld;
// SurfaceElementIndex sei;
Array<SurfaceElementIndex> seia;
mesh.GetSurfaceElementsOfFace (faceindex, seia);
bool mixed = 0;
for (int i = 0; i < seia.Size(); i++)
if (mesh[seia[i]].GetNP() != 3)
{
mixed = 1;
break;
}
int loci;
double fact;
int moveisok;
PointGeomInfo ngi;
Point3d origp;
Vec3d n1, n2;
Vector x(2), xedge(1);
Array<MeshPoint, PointIndex::BASE> savepoints(mesh.GetNP());
ld.uselocalh = mp.uselocalh;
Array<int, PointIndex::BASE> nelementsonpoint(mesh.GetNP());
nelementsonpoint = 0;
for (int i = 0; i < seia.Size(); i++)
{
const Element2d & el = mesh[seia[i]];
for (int j = 0; j < el.GetNP(); j++)
nelementsonpoint[el[j]]++;
}
TABLE<SurfaceElementIndex,PointIndex::BASE> elementsonpoint(nelementsonpoint);
for (int i = 0; i < seia.Size(); i++)
{
const Element2d & el = mesh[seia[i]];
for (int j = 0; j < el.GetNP(); j++)
elementsonpoint.Add (el[j], seia[i]);
}
ld.loch = mp.maxh;
ld.locmetricweight = metricweight;
ld.meshthis = this;
Opti2SurfaceMinFunction surfminf(mesh, ld);
Opti2EdgeMinFunction edgeminf(mesh, ld);
Opti2SurfaceMinFunctionJacobian surfminfj(mesh, ld);
OptiParameters par;
par.maxit_linsearch = 8;
par.maxit_bfgs = 5;
/*
int i, j, k;
if (improveedges)
for (i = 1; i <= mesh.GetNP(); i++)
if (mesh.PointType(i) == EDGEPOINT)
{
continue;
PrintDot ();
sp1 = mesh.Point(i);
locelements.SetSize(0);
locrots.SetSize (0);
lochs.SetSize (0);
surfi = surfi2 = surfi3 = 0;
for (j = 0; j < elementsonpoint[i].Size(); j++)
{
sei = elementsonpoint[i][j];
const Element2d * bel = &mesh[sei];
if (!surfi)
surfi = mesh.GetFaceDescriptor(bel->GetIndex()).SurfNr();
else if (surfi != mesh.GetFaceDescriptor(bel->GetIndex()).SurfNr())
{
if (surfi2 != 0 && surfi2 !=
mesh.GetFaceDescriptor(bel->GetIndex()).SurfNr())
surfi3 = mesh.GetFaceDescriptor(bel->GetIndex()).SurfNr();
else
surfi2 = mesh.GetFaceDescriptor(bel->GetIndex()).SurfNr();
}
locelements.Append (sei);
if (bel->PNum(1) == i)
locrots.Append (1);
else if (bel->PNum(2) == i)
locrots.Append (2);
else
locrots.Append (3);
if (uselocalh)
{
Point3d pmid = Center (mesh.Point(bel->PNum(1)),
mesh.Point(bel->PNum(2)),
mesh.Point(bel->PNum(3)));
lochs.Append (mesh.GetH(pmid));
}
}
if (surfi2 && !surfi3)
{
GetNormalVector (surfi, sp1, n1);
GetNormalVector (surfi2, sp1, n2);
t1 = Cross (n1, n2);
xedge = 0;
BFGS (xedge, edgeminf, par, 1e-6);
mesh.Point(i).X() += xedge.Get(1) * t1.X();
mesh.Point(i).Y() += xedge.Get(1) * t1.Y();
mesh.Point(i).Z() += xedge.Get(1) * t1.Z();
ProjectPoint2 (surfi, surfi2, mesh.Point(i));
}
}
*/
bool printeddot = 0;
char plotchar = '.';
int modplot = 1;
if (mesh.GetNP() > 1000)
{
plotchar = '+';
modplot = 10;
}
if (mesh.GetNP() > 10000)
{
plotchar = 'o';
modplot = 100;
}
int cnt = 0;
NgProfiler::StopTimer (timer1);
for (PointIndex pi = PointIndex::BASE; pi < mesh.GetNP()+PointIndex::BASE; pi++)
if (mesh[pi].Type() == SURFACEPOINT)
{
if (multithread.terminate)
throw NgException ("Meshing stopped");
cnt++;
if (cnt % modplot == 0 && writestatus)
{
printeddot = 1;
PrintDot (plotchar);
}
if (elementsonpoint[pi].Size() == 0)
continue;
ld.sp1 = mesh[pi];
Element2d & hel = mesh[elementsonpoint[pi][0]];
int hpi = 0;
for (int j = 1; j <= hel.GetNP(); j++)
if (hel.PNum(j) == pi)
{
hpi = j;
break;
}
ld.gi1 = hel.GeomInfoPi(hpi);
SelectSurfaceOfPoint (ld.sp1, ld.gi1);
ld.locelements.SetSize(0);
ld.locrots.SetSize (0);
ld.lochs.SetSize (0);
for (int j = 0; j < elementsonpoint[pi].Size(); j++)
{
SurfaceElementIndex sei = elementsonpoint[pi][j];
const Element2d & bel = mesh[sei];
ld.surfi = mesh.GetFaceDescriptor(bel.GetIndex()).SurfNr();
ld.locelements.Append (sei);
for (int k = 1; k <= bel.GetNP(); k++)
if (bel.PNum(k) == pi)
{
ld.locrots.Append (k);
break;
}
if (ld.uselocalh)
{
Point3d pmid = Center (mesh[bel[0]], mesh[bel[1]], mesh[bel[2]]);
ld.lochs.Append (mesh.GetH(pmid));
}
}
GetNormalVector (ld.surfi, ld.sp1, ld.gi1, ld.normal);
ld.t1 = ld.normal.GetNormal ();
ld.t2 = Cross (ld.normal, ld.t1);
// save points, and project to tangential plane
for (int j = 0; j < ld.locelements.Size(); j++)
{
const Element2d & el = mesh[ld.locelements[j]];
for (int k = 0; k < el.GetNP(); k++)
savepoints[el[k]] = mesh[el[k]];
}
for (int j = 0; j < ld.locelements.Size(); j++)
{
const Element2d & el = mesh[ld.locelements[j]];
for (int k = 0; k < el.GetNP(); k++)
{
PointIndex hhpi = el[k];
double lam = ld.normal * (mesh[hhpi] - ld.sp1);
mesh[hhpi] -= lam * ld.normal;
}
}
x = 0;
par.typx = ld.lochs[0];
if (mixed)
{
// (*testout) << "vorher : " << surfminfj.Func (x) << endl;
BFGS (x, surfminfj, par, 1e-6);
// (*testout) << "nachher: " << surfminfj.Func (x) << endl;
// (*testout) << "x = " << x << endl;
}
else
{
// (*testout) << "vorher : " << surfminf.Func (x) << endl;
BFGS (x, surfminf, par, 1e-6);
// (*testout) << "nachher: " << surfminf.Func (x) << endl;
// (*testout) << "x = " << x << endl;
}
origp = mesh[pi];
loci = 1;
fact = 1;
moveisok = 0;
// restore other points
for (int j = 0; j < ld.locelements.Size(); j++)
{
const Element2d & el = mesh[ld.locelements[j]];
for (int k = 0; k < el.GetNP(); k++)
{
PointIndex hhpi = el[k];
if (hhpi != pi) mesh[hhpi] = savepoints[hhpi];
}
}
//optimizer loop (if whole distance is not possible, move only a bit!!!!)
while (loci <= 5 && !moveisok)
{
loci ++;
/*
mesh[pi].X() = origp.X() + (x.Get(1) * t1.X() + x.Get(2) * t2.X())*fact;
mesh[pi].Y() = origp.Y() + (x.Get(1) * t1.Y() + x.Get(2) * t2.Y())*fact;
mesh[pi].Z() = origp.Z() + (x.Get(1) * t1.Z() + x.Get(2) * t2.Z())*fact;
*/
Vec<3> hv = x(0) * ld.t1 + x(1) * ld.t2;
Point3d hnp = origp + Vec3d (hv);
mesh[pi](0) = hnp.X();
mesh[pi](1) = hnp.Y();
mesh[pi](2) = hnp.Z();
fact = fact/2.;
// ProjectPoint (surfi, mesh[pi]);
// moveisok = CalcPointGeomInfo(surfi, ngi, mesh[pi]);
ngi = ld.gi1;
moveisok = ProjectPointGI (ld.surfi, mesh[pi], ngi);
// point lies on same chart in stlsurface
if (moveisok)
{
for (int j = 0; j < ld.locelements.Size(); j++)
mesh[ld.locelements[j]].GeomInfoPi(ld.locrots[j]) = ngi;
}
else
{
mesh[pi] = Point<3> (origp);
}
}
}
if (printeddot)
PrintDot ('\n');
CheckMeshApproximation (mesh);
mesh.SetNextTimeStamp();
}
void MeshOptimize2d :: GetNormalVector(INDEX /* surfind */, const Point<3> & p, Vec<3> & nv) const
{
nv = Vec<3> (0, 0, 1);
}
void MeshOptimize2d :: GetNormalVector(INDEX surfind, const Point<3> & p, PointGeomInfo & gi, Vec<3> & n) const
{
GetNormalVector (surfind, p, n);
}
}