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implement functionality to restrict meshsize in base class

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not yet used in any derived geometry
This commit is contained in:
Christopher Lackner 2019-10-28 19:58:35 +01:00
parent b5936543e9
commit a76d407979
2 changed files with 126 additions and 3 deletions
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111
libsrc/meshing/basegeom.cpp
View File

@ -10,6 +10,81 @@ namespace netgen
GeometryRegister :: ~GeometryRegister()
{ ; }
void GeometryFace :: RestrictHTrig(Mesh& mesh,
const PointGeomInfo& gi0,
const PointGeomInfo& gi1,
const PointGeomInfo& gi2,
const MeshingParameters& mparam,
int depth, double h) const
{
auto p0 = GetPoint(gi0);
auto p1 = GetPoint(gi1);
auto p2 = GetPoint(gi2);
auto longest = (p0-p1).Length();
int cutedge = 2;
if(auto len = (p0-p2).Length(); len > longest)
{
longest = len;
cutedge = 1;
}
if(auto len = (p1-p2).Length(); len > longest)
{
longest = len;
cutedge = 0;
}
PointGeomInfo gi_mid;
gi_mid.u = (gi0.u + gi1.u + gi2.u)/3;
gi_mid.v = (gi0.v + gi1.v + gi2.v)/3;
if(depth % 3 == 0)
{
double curvature = 0.;
curvature = max2(max2(curvature, GetCurvature(gi_mid)),
max3(GetCurvature(gi0), GetCurvature(gi1),
GetCurvature(gi2)));
if(curvature < 1e-3)
return;
double kappa = curvature * mparam.curvaturesafety;
h = mparam.maxh * kappa < 1 ? mparam.maxh : 1./kappa;
if(h < 1e-4 * longest)
return;
}
if(h < longest && depth < 10)
{
if(cutedge == 0)
{
PointGeomInfo gi_m;
gi_m.u = 0.5 * (gi1.u + gi2.u);
gi_m.v = 0.5 * (gi1.v + gi2.v);
RestrictHTrig(mesh, gi_m, gi2, gi0, mparam, depth+1, h);
RestrictHTrig(mesh, gi_m, gi0, gi1, mparam, depth+1, h);
}
else if(cutedge == 1)
{
PointGeomInfo gi_m;
gi_m.u = 0.5 * (gi0.u + gi2.u);
gi_m.v = 0.5 * (gi0.v + gi2.v);
RestrictHTrig(mesh, gi_m, gi1, gi2, mparam, depth+1, h);
RestrictHTrig(mesh, gi_m, gi0, gi1, mparam, depth+1, h);
}
else if(cutedge == 2)
{
PointGeomInfo gi_m;
gi_m.u = 0.5 * (gi0.u + gi1.u);
gi_m.v = 0.5 * (gi0.v + gi1.v);
RestrictHTrig(mesh, gi_m, gi1, gi2, mparam, depth+1, h);
RestrictHTrig(mesh, gi_m, gi2, gi0, mparam, depth+1, h);
}
}
else
{
auto pmid = GetPoint(gi_mid);
for(const auto& p : {p0, p1, p2, pmid})
mesh.RestrictLocalH(p, h);
}
}
void NetgenGeometry :: Analyse(Mesh& mesh,
const MeshingParameters& mparam) const
{
@ -21,7 +96,41 @@ namespace netgen
mparam.grading);
if(mparam.uselocalh)
RestrictLocalMeshsize(mesh, mparam);
{
double eps = 1e-12 * bounding_box.Diam();
// restrict meshsize on edges
for(const auto & edge : edges)
{
auto length = edge->GetLength();
// skip very short edges
if(length < eps)
continue;
static constexpr int npts = 20;
// restrict mesh size based on edge length
for(auto i : Range(npts+1))
mesh.RestrictLocalH(edge->GetPoint(double(i)/npts), length/mparam.segmentsperedge);
// restrict mesh size based on edge curvature
double t = 0.;
auto p_old = edge->GetPoint(t);
while(t < 1.-eps)
{
t += edge->CalcStep(t, 1./mparam.curvaturesafety);
if(t < 1.)
{
auto p = edge->GetPoint(t);
auto dist = (p-p_old).Length();
mesh.RestrictLocalH(p, dist);
p_old = p;
}
}
}
// restrict meshsize on faces
for(const auto& face : faces)
face->RestrictH(mesh, mparam);
}
mesh.LoadLocalMeshSize(mparam.meshsizefilename);
}

18
libsrc/meshing/basegeom.hpp
View File

@ -28,6 +28,8 @@ namespace netgen
virtual const GeometryVertex& GetEndVertex() const = 0;
virtual double GetLength() const = 0;
virtual Point<3> GetPoint(double t) const = 0;
// Calculate parameter step respecting edges sag value
virtual double CalcStep(double t, double sag) const = 0;
virtual bool OrientedLikeGlobal() const = 0;
virtual size_t GetHash() const = 0;
};
@ -42,10 +44,24 @@ namespace netgen
// Project point using geo info. Fast if point is close to
// parametrization in geo info.
virtual bool ProjectPointGI(Point<3>& p, PointGeomInfo& gi) const =0;
virtual Point<3> GetPoint(const PointGeomInfo& gi) const = 0;
virtual void CalcEdgePointGI(const GeometryEdge& edge,
double t,
EdgePointGeomInfo& egi) const = 0;
virtual Box<3> GetBoundingBox() const = 0;
// Get curvature in point from local coordinates in PointGeomInfo
virtual double GetCurvature(const PointGeomInfo& gi) const = 0;
virtual void RestrictH(Mesh& mesh, const MeshingParameters& mparam) const = 0;
protected:
void RestrictHTrig(Mesh& mesh,
const PointGeomInfo& gi0,
const PointGeomInfo& gi1,
const PointGeomInfo& gi2,
const MeshingParameters& mparam,
int depth = 0, double h = 0.) const;
};
class DLL_HEADER NetgenGeometry
@ -76,8 +92,6 @@ namespace netgen
virtual Mesh::GEOM_TYPE GetGeomType() const { return Mesh::NO_GEOM; }
virtual void Analyse(Mesh& mesh,
const MeshingParameters& mparam) const;
virtual void RestrictLocalMeshsize(Mesh& mesh,
const MeshingParameters& mparam) const {}
virtual void FindEdges(Mesh& mesh, const MeshingParameters& mparam) const;
virtual void MeshSurface(Mesh& mesh, const MeshingParameters& mparam) const;
virtual void OptimizeSurface(Mesh& mesh, const MeshingParameters& mparam) const;