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automatic 2d mesh-size control
This commit is contained in:
Joachim Schoeberl
parent
4dcae7ec4d
commit
2637b547b5
@ -9,51 +9,116 @@ namespace netgen
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void CalcPartition (const SplineSegExt & spline, double l,
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MeshingParameters & mp, double h, double h1, double h2,
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double hcurve, double elto0,
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Array<double> & points);
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void CalcPartition (const SplineSegExt & spline,
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// double l,
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MeshingParameters & mp, Mesh & mesh,
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// double h, double h1, double h2, double hcurve,
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double elto0, Array<double> & points)
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{
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double fperel, oldf, f;
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int n = 10000;
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Array<Point<2> > xi(n);
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Array<double> hi(n);
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for (int i = 0; i < n; i++)
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{
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xi[i] = spline.GetPoint ( (i+0.5) / n );
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hi[i] = mesh.GetH (Point<3> (xi[i](0), xi[i](1), 0));
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}
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// limit slope
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double gradh = 1/elto0;
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for (int i = 0; i < n-1; i++)
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{
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double hnext = hi[i] + gradh * (xi[i+1]-xi[i]).Length();
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hi[i+1] = min(hi[i+1], hnext);
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}
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for (int i = n-1; i > 1; i--)
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{
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double hnext = hi[i] + gradh * (xi[i-1]-xi[i]).Length();
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hi[i-1] = min(hi[i-1], hnext);
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}
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points.SetSize (0);
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double len = spline.Length();
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double dt = len / n;
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double sum = 0;
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for (int i = 1; i <= n; i++)
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{
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double t = (i-0.5)*dt;
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double fun = hi[i-1];
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sum += dt / fun;
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}
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int nel = int (sum+1);
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fperel = sum / nel;
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points.Append (0);
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int i = 1;
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oldf = 0;
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for (int j = 1; j <= n && i < nel; j++)
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{
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double t = (j-0.5)*dt;
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double fun = hi[j-1];
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f = oldf + dt / fun;
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while (i * fperel < f && i < nel)
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{
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points.Append ( dt * (j-1) + (i * fperel - oldf) * fun);
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i++;
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}
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oldf = f;
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t += dt;
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}
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points.Append (len);
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}
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// partitionizes spline curve
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void Partition (const SplineSegExt & spline,
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MeshingParameters & mp, double h, double elto0,
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Mesh & mesh, Point3dTree & searchtree, int segnr)
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{
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enum { D = 2 };
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int i, j;
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double l; // , r1, r2, ra;
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double lold, dt, frac;
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int n = 100;
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Point<D> p, pold, mark, oldmark;
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Point<2> mark, oldmark;
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Array<double> curvepoints;
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double edgelength, edgelengthold;
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l = spline.Length();
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double h1 = min (spline.StartPI().hmax, h/spline.StartPI().refatpoint);
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double h2 = min (spline.EndPI().hmax, h/spline.EndPI().refatpoint);
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double hcurve = min (spline.hmax, h/spline.reffak);
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CalcPartition (spline, mp, mesh, elto0, curvepoints);
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CalcPartition (spline, l, mp, h, h1, h2, hcurve, elto0, curvepoints);
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// cout << "curvepoints = " << curvepoints << endl;
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double dt = 1.0 / n;
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dt = 1.0 / n;
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int j = 1;
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l = 0;
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j = 1;
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pold = spline.GetPoint (0);
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lold = 0;
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Point<2> pold = spline.GetPoint (0);
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double lold = 0;
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oldmark = pold;
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edgelengthold = 0;
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Array<int> locsearch;
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for (i = 1; i <= n; i++)
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for (int i = 1; i <= n; i++)
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{
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p = spline.GetPoint (i*dt);
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l = lold + Dist (p, pold);
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Point<2> p = spline.GetPoint (i*dt);
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double l = lold + Dist (p, pold);
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while (j < curvepoints.Size() && (l >= curvepoints[j] || i == n))
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{
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frac = (curvepoints[j]-lold) / (l-lold);
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double frac = (curvepoints[j]-lold) / (l-lold);
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edgelength = i*dt + (frac-1)*dt;
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// mark = pold + frac * (p-pold);
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mark = spline.GetPoint (edgelength);
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@ -72,27 +137,12 @@ namespace netgen
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for (int k = 0; k < locsearch.Size(); k++)
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if ( mesh[PointIndex(locsearch[k])].GetLayer() == spline.layer)
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pi1 = locsearch[k];
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// if (locsearch.Size()) pi1 = locsearch[0];
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searchtree.GetIntersecting (mark3 - v, mark3 + v, locsearch);
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for (int k = 0; k < locsearch.Size(); k++)
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if ( mesh[PointIndex(locsearch[k])].GetLayer() == spline.layer)
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pi2 = locsearch[k];
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// if (locsearch.Size()) pi2 = locsearch[0];
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/*
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for (PointIndex pk = PointIndex::BASE;
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pk < mesh.GetNP()+PointIndex::BASE; pk++)
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{
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if (Dist (mesh[pk], oldmark3) < 1e-4 * h) pi1 = pk;
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if (Dist (mesh[pk], mark3) < 1e-4 * h) pi2 = pk;
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}
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*/
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// cout << "pi1 = " << pi1 << endl;
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// cout << "pi2 = " << pi2 << endl;
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if (pi1 == -1)
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{
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pi1 = mesh.AddPoint(oldmark3, spline.layer);
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@ -157,24 +207,52 @@ namespace netgen
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if (dom != 0) GetSpline(i).layer = GetDomainLayer (dom);
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}
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// mesh size restrictions ...
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for (int i = 0; i < splines.Size(); i++)
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{
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const SplineSegExt & spline = GetSpline(i);
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const GeomPoint<2> & p1 = spline.StartPI();
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const GeomPoint<2> & p2 = spline.EndPI();
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double h1 = min (p1.hmax, h/p1.refatpoint);
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mesh2d.RestrictLocalH (Point<3>(p1(0),p1(1),0), h1);
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double h2 = min (p2.hmax, h/p2.refatpoint);
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mesh2d.RestrictLocalH (Point<3>(p2(0),p2(1),0), h2);
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double len = spline.Length();
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mesh2d.RestrictLocalHLine (Point<3>(p1(0),p1(1),0),
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Point<3>(p2(0),p2(1),0), len/mp.segmentsperedge);
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double hcurve = min (spline.hmax, h/spline.reffak);
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double hl = GetDomainMaxh (spline.leftdom);
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if (hl > 0) hcurve = min2 (hcurve, hl);
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double hr = GetDomainMaxh (spline.rightdom);
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if (hr > 0) hcurve = min2 (hcurve, hr);
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int np = 1000;
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for (double t = 0.5/np; t < 1; t += 1.0/np)
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{
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Point<2> x = spline.GetPoint(t);
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double hc = 1.0/mp.curvaturesafety / (1e-99+spline.CalcCurvature (t));
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mesh2d.RestrictLocalH (Point<3> (x(0), x(1), 0), min2(hc, spline.hmax));
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}
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}
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for (int i = 0; i < splines.Size(); i++)
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if (GetSpline(i).copyfrom == -1)
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{
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// astrid - set boundary meshsize to domain meshsize h
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// if no domain mesh size is given, the max h value from the bounding box is used
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double minimum = min2 ( GetDomainMaxh ( GetSpline(i).leftdom ), GetDomainMaxh ( GetSpline(i).rightdom ) );
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double maximum = max2 ( GetDomainMaxh ( GetSpline(i).leftdom ), GetDomainMaxh ( GetSpline(i).rightdom ) );
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minimum = min2 ( minimum, h );
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maximum = min2 ( maximum, h);
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if ( minimum > 0 )
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// GetSpline(i).Partition(minimum, elto0, mesh2d, searchtree, i+1);
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Partition(GetSpline(i), mp, minimum, elto0, mesh2d, searchtree, i+1);
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else if ( maximum > 0 )
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// GetSpline(i).Partition(maximum, elto0, mesh2d, searchtree, i+1);
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Partition(GetSpline(i), mp, maximum, elto0, mesh2d, searchtree, i+1);
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else
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// GetSpline(i).Partition(h, elto0, mesh2d, searchtree, i+1);
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Partition(GetSpline(i), mp, h, elto0, mesh2d, searchtree, i+1);
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double hl = GetDomainMaxh ( GetSpline(i).leftdom );
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double hr = GetDomainMaxh ( GetSpline(i).rightdom );
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double useh = h;
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if (hl > 0) useh = min2 (h, hl);
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if (hr > 0) useh = min2 (h, hr);
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Partition(GetSpline(i), mp, useh, elto0, mesh2d, searchtree, i+1);
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}
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else
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{
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@ -298,6 +376,14 @@ namespace netgen
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mesh = new Mesh;
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mesh->SetDimension (2);
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Point3d pmin(bbox.PMin()(0), bbox.PMin()(1), -bbox.Diam());
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Point3d pmax(bbox.PMax()(0), bbox.PMax()(1), bbox.Diam());
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mesh->SetLocalH (pmin, pmax, mparam.grading);
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mesh->SetGlobalH (h);
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geometry.PartitionBoundary (mp, h, *mesh);
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@ -347,11 +433,6 @@ namespace netgen
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for (SegmentIndex si = 0; si < mesh->GetNSeg(); si++)
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(*mesh)[si].SetBCName ( (*mesh).GetBCNamePtr( (*mesh)[si].si-1 ) );
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Point3d pmin(bbox.PMin()(0), bbox.PMin()(1), -bbox.Diam());
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Point3d pmax(bbox.PMax()(0), bbox.PMax()(1), bbox.Diam());
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mesh->SetLocalH (pmin, pmax, mparam.grading);
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mesh->SetGlobalH (h);
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mesh->CalcLocalH(mparam.grading);
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@ -488,12 +569,7 @@ namespace netgen
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mparam.checkoverlap = 0;
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/*
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if (!mparam.quad)
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meshing.Delaunay (*mesh, domnr, mparam);
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else
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*/
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meshing.GenerateMesh (*mesh, mparam, h, domnr);
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for (SurfaceElementIndex sei = oldnf; sei < mesh->GetNSE(); sei++)
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@ -884,99 +884,6 @@ namespace netgen
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void CalcPartition (const SplineSegExt & spline, double l,
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MeshingParameters & mp, double h, double h1, double h2,
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double hcurve, double elto0, Array<double> & points)
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{
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double fperel, oldf, f;
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int n = 10000;
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Array<Point<2> > xi(n);
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Array<double> hi(n);
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hi = h;
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for (int i = 0; i < n; i++)
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{
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xi[i] = spline.GetPoint ( (i+0.5) / n );
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double hc = 1.0/mp.curvaturesafety / (1e-20+spline.CalcCurvature ( (i+0.5) / n ));
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// *testout << "t = " << (i+0.5)/n << ", xi = " << xi[i] << ", hi = " << hc << endl;
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hi[i] = min2(hi[i], hc);
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}
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hi[0] = min (hi[0], h1);
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hi[n-1] = min (hi[n-1], h2);
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if ( (spline.GetPoint(0)-spline.GetPoint(1)).Length() < 1e-12 )
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hi[0] = hi[n-1] = min2 (hi[0], hi[n-1]);
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// limit slope
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double gradh = 1/elto0;
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for (int i = 0; i < n-1; i++)
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{
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double hnext = hi[i] + gradh * (xi[i+1]-xi[i]).Length();
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hi[i+1] = min(hi[i+1], hnext);
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}
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for (int i = n-1; i > 1; i--)
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{
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double hnext = hi[i] + gradh * (xi[i-1]-xi[i]).Length();
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hi[i-1] = min(hi[i-1], hnext);
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}
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points.SetSize (0);
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double dt = l / n;
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double sum = 0;
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for (int i = 1; i <= n; i++)
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{
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double t = (i-0.5)*dt;
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/*
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double fun = min3 (hcurve, t/elto0 + h1, (l-t)/elto0 + h2);
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double curv = spline.CalcCurvature (t/l);
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cout << "curv = " << curv << endl;
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if (curv < 1e-10) curv = 1e-10;
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fun = min2 (fun, 0.1/curv);
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*/
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double fun = hi[i-1];
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sum += dt / fun;
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}
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int nel = int (sum+1);
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fperel = sum / nel;
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points.Append (0);
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int i = 1;
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oldf = 0;
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// t = 0.5 * dt;
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for (int j = 1; j <= n && i < nel; j++)
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{
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double t = (j-0.5)*dt;
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double fun = hi[j-1];
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/*
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double fun = min3 (hcurve, t/elto0 + h1, (l-t)/elto0 + h2);
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double curv = spline.CalcCurvature (t/l);
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if (curv < 1e-10) curv = 1e-10;
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fun = min2 (fun, 0.1/curv);
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*/
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f = oldf + dt / fun;
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while (i * fperel < f && i < nel)
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{
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points.Append ( dt * (j-1) + (i * fperel - oldf) * fun);
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i++;
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}
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oldf = f;
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t += dt;
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}
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points.Append (l);
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}
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