From 5f93b0584156b8e63cdcdb3574f14fb5ce4fd8d3 Mon Sep 17 00:00:00 2001
From: Jean-Francois Remacle <jean-francois.remacle@uclouvain.be>
Date: Fri, 18 Sep 2009 15:05:54 +0000
Subject: [PATCH] add an option to remove four-triangles vertices
---
Common/Context.h | 2 +-
Common/DefaultOptions.h | 2 +
Common/Options.cpp | 12 ++++
Common/Options.h | 1 +
Fltk/optionWindow.cpp | 6 ++
Mesh/meshGFace.cpp | 2 +
Mesh/meshGFaceOptimize.cpp | 132 ++++++++++++++++++++++++++++++++++---
Mesh/meshGFaceOptimize.h | 1 +
8 files changed, 147 insertions(+), 11 deletions(-)
diff --git a/Common/Context.h b/Common/Context.h
index 539f3677a1..4a00be4e9a 100644
--- a/Common/Context.h
+++ b/Common/Context.h
@@ -166,7 +166,7 @@ class CTX {
int points, lines, triangles, quadrangles, tetrahedra, hexahedra, prisms, pyramids;
int surfacesEdges, surfacesFaces, volumesEdges, volumesFaces, numSubEdges;
int pointsNum, linesNum, surfacesNum, volumesNum;
- int optimize, optimizeNetgen, refineSteps, qualityType, labelType;
+ int optimize, optimizeNetgen, refineSteps, qualityType, labelType, remove4triangles;
double normals, tangents, explode, angleSmoothNormals, allowSwapEdgeAngle;
double mshFileVersion, labelFrequency, pointSize, lineWidth;
double qualityInf, qualitySup, radiusInf, radiusSup;
diff --git a/Common/DefaultOptions.h b/Common/DefaultOptions.h
index cadc1fb5c3..39fec36ddf 100644
--- a/Common/DefaultOptions.h
+++ b/Common/DefaultOptions.h
@@ -1166,6 +1166,8 @@ StringXNumber MeshOptions_Number[] = {
"RandomFactor * size(triangle)/size(model) approaches machine accuracy)" },
{ F|O, "RefineSteps" , opt_mesh_refine_steps , 10 ,
"Number of refinement steps in the MeshAdapt-based 2D algorithms" },
+ { F|O, "Remove4Triangles" , opt_mesh_remove_4_triangles , 0 ,
+ "Try to remove nodes surrounded by 4 triangles in 2D triangular meshes" },
{ F|O, "ReverseAllNormals" , opt_mesh_reverse_all_normals , 0. ,
"Reverse all the mesh normals (for display)" },
diff --git a/Common/Options.cpp b/Common/Options.cpp
index 5a113c3ba8..a9324779f5 100644
--- a/Common/Options.cpp
+++ b/Common/Options.cpp
@@ -4693,6 +4693,18 @@ double opt_mesh_optimize_netgen(OPT_ARGS_NUM)
#endif
return CTX::instance()->mesh.optimizeNetgen;
}
+double opt_mesh_remove_4_triangles(OPT_ARGS_NUM)
+{
+ if(action & GMSH_SET)
+ CTX::instance()->mesh.remove4triangles = (int)val;
+#if defined(HAVE_FLTK)
+ if(FlGui::available() && (action & GMSH_GUI))
+ FlGui::instance()->options->mesh.butt[25]->value
+ (CTX::instance()->mesh.remove4triangles);
+#endif
+ return CTX::instance()->mesh.remove4triangles;
+
+}
double opt_mesh_refine_steps(OPT_ARGS_NUM)
{
diff --git a/Common/Options.h b/Common/Options.h
index 5d33eb1d85..1d2e060a11 100644
--- a/Common/Options.h
+++ b/Common/Options.h
@@ -446,6 +446,7 @@ double opt_geometry_match_geom_and_mesh(OPT_ARGS_NUM);
double opt_mesh_label_frequency(OPT_ARGS_NUM);
double opt_mesh_optimize(OPT_ARGS_NUM);
double opt_mesh_optimize_netgen(OPT_ARGS_NUM);
+double opt_mesh_remove_4_triangles(OPT_ARGS_NUM);
double opt_mesh_refine_steps(OPT_ARGS_NUM);
double opt_mesh_normals(OPT_ARGS_NUM);
double opt_mesh_num_sub_edges(OPT_ARGS_NUM);
diff --git a/Fltk/optionWindow.cpp b/Fltk/optionWindow.cpp
index 87fd8894c1..d372f09d25 100644
--- a/Fltk/optionWindow.cpp
+++ b/Fltk/optionWindow.cpp
@@ -400,6 +400,7 @@ static void mesh_options_ok_cb(Fl_Widget *w, void *data)
opt_mesh_lc_extend_from_boundary(0, GMSH_SET, o->mesh.butt[16]->value());
opt_mesh_optimize(0, GMSH_SET, o->mesh.butt[2]->value());
opt_mesh_optimize_netgen(0, GMSH_SET, o->mesh.butt[24]->value());
+ opt_mesh_remove_4_triangles(0,GMSH_SET, o->mesh.butt[25]->value());
opt_mesh_order(0, GMSH_SET, o->mesh.value[3]->value());
opt_mesh_smooth_internal_edges(0, GMSH_SET, o->mesh.butt[3]->value());
opt_mesh_second_order_incomplete(0, GMSH_SET, o->mesh.butt[4]->value());
@@ -1985,6 +1986,11 @@ optionWindow::optionWindow(int deltaFontSize)
(L + 2 * WB, 2 * WB + 6 * BH, BW, BH, "Optimize high order mesh (2D-plane only)");
mesh.butt[3]->type(FL_TOGGLE_BUTTON);
mesh.butt[3]->callback(mesh_options_ok_cb);
+
+ mesh.butt[25] = new Fl_Check_Button
+ (L + 2 * WB, 2 * WB + 7 * BH, BW, BH, "Try to remove 4 triangles nodes");
+ mesh.butt[25]->type(FL_TOGGLE_BUTTON);
+ mesh.butt[25]->callback(mesh_options_ok_cb);
o->end();
}
diff --git a/Mesh/meshGFace.cpp b/Mesh/meshGFace.cpp
index 94598e5b3b..ed91872a29 100644
--- a/Mesh/meshGFace.cpp
+++ b/Mesh/meshGFace.cpp
@@ -663,6 +663,8 @@ static bool gmsh2DMeshGenerator(GFace *gf, int RECUR_ITER,
sprintf(name, "param%d.pos", gf->tag());
outputScalarField(m->triangles, name,1);
}
+ if(CTX::instance()->mesh.remove4triangles)
+ removeFourTrianglesNodes(gf,false);
// delete the mesh
delete m;
diff --git a/Mesh/meshGFaceOptimize.cpp b/Mesh/meshGFaceOptimize.cpp
index a7f3b14645..c837123716 100644
--- a/Mesh/meshGFaceOptimize.cpp
+++ b/Mesh/meshGFaceOptimize.cpp
@@ -205,6 +205,128 @@ void parametricCoordinates(MElement *t, GFace *gf, double u[4], double v[4])
}
}
+double surfaceTriangleUV(MElement *t,GFace *gf){
+ double u[4],v[4];
+ parametricCoordinates(t,gf,u,v);
+ return 0.5*fabs((u[1]-u[0])*(v[2]-v[0])-(u[2]-u[0])*(v[1]-v[0]));
+}
+
+double surfaceTriangleUV(MVertex *v1, MVertex *v2, MVertex *v3,
+ const std::vector<double> &Us,
+ const std::vector<double> &Vs)
+{
+ const double v12[2] = {Us[v2->getIndex()] - Us[v1->getIndex()],
+ Vs[v2->getIndex()] - Vs[v1->getIndex()]};
+ const double v13[2] = {Us[v3->getIndex()] - Us[v1->getIndex()],
+ Vs[v3->getIndex()] - Vs[v1->getIndex()]};
+ return 0.5 * fabs (v12[0] * v13[1] - v12[1] * v13[0]);
+}
+
+int _removeFourTrianglesNodes(GFace *gf,bool replace_by_quads)
+{
+
+ v2t_cont adj;
+ buildVertexToElement(gf->triangles,adj);
+ v2t_cont :: iterator it = adj.begin();
+ int n=0;
+ std::set<MElement*> touched;
+ while (it != adj.end()) {
+ bool skip=false;
+ double surfaceRef=0;
+ if(it->second.size()==4) {
+ const std::vector<MElement*> < = it->second;
+ MVertex* edges[4][2];
+ for(int i=0;i<4;i++) {
+ if(touched.find(lt[i])!=touched.end() || lt[i]->getNumVertices()!=3){
+ skip=true;
+ break;
+ }
+ int j;
+
+ surfaceRef+=surfaceTriangleUV(lt[i],gf);
+ for(j=0;j<3;j++) {
+ if(lt[i]->getVertex(j)==it->first) {
+ edges[i][0] = lt[i]->getVertex((j+1)%3);
+ edges[i][1] = lt[i]->getVertex((j+2)%3);
+ break;
+ }
+ }
+ if(j==3)
+ throw;
+ }
+ if(skip){
+ it++;
+ continue;
+ }
+
+ for(int i=1;i<3;i++) {
+ for(int j=i+1;j<4;j++) {
+ if(edges[j][0]==edges[i-1][1]){
+ MVertex *buf[2]={edges[i][0],edges[i][1]};
+ edges[i][0]=edges[j][0];
+ edges[i][1]=edges[j][1];
+ edges[j][0]=buf[0];
+ edges[j][1]=buf[1];
+ break;
+ }
+ }
+ }
+ if(edges[0][1]==edges[1][0] && edges[1][1]==edges[2][0] && edges[2][1] == edges[3][0] && edges[3][1]==edges[0][0]) {
+ if(replace_by_quads){
+ gf->quadrangles.push_back(new MQuadrangle(edges[0][0],edges[1][0],edges[2][0],edges[3][0]));
+ }else{
+ MTriangle *newt[4];
+ double surf[4],qual[4];
+ for(int i=0;i<4;i++){
+ newt[i] = new MTriangle(edges[i][0],edges[(i+1)%4][0],edges[(i+2)%4][0]);
+ surf[i]=surfaceTriangleUV(newt[i],gf);
+ qual[i]=qmTriangle(newt[i],QMTRI_RHO);
+ }
+ double q02=(fabs((surf[0]+surf[2]-surfaceRef)/surfaceRef)<1e-8) ? std::min(qual[0],qual[2]) : -1;
+ double q13=(fabs((surf[1]+surf[3]-surfaceRef)/surfaceRef)<1e-8) ? std::min(qual[1],qual[3]) : -1;
+ if(q02>q13 && q02 >0) {
+ delete newt[1];
+ delete newt[3];
+ gf->triangles.push_back(newt[0]);
+ gf->triangles.push_back(newt[2]);
+ } else if (q13 >0) {
+ delete newt[0];
+ delete newt[2];
+ gf->triangles.push_back(newt[1]);
+ gf->triangles.push_back(newt[3]);
+ } else {
+ it++;
+ throw;
+ continue;
+ }
+ }
+ for(int i=0;i<4;i++) {
+ touched.insert(lt[i]);
+ }
+ n++;
+ }
+ }
+ it++;
+ }
+ std::vector<MTriangle*> triangles2;
+ for(unsigned int i = 0; i < gf->triangles.size(); i++){
+ if(touched.find(gf->triangles[i]) == touched.end()){
+ triangles2.push_back(gf->triangles[i]);
+ }
+ else {
+ delete gf->triangles[i];
+ }
+ }
+ gf->triangles = triangles2;
+ Msg::Debug("%i four-triangles vertices removed",n);
+ return n;
+}
+
+void removeFourTrianglesNodes(GFace *gf,bool replace_by_quads)
+{
+ while(_removeFourTrianglesNodes(gf,replace_by_quads));
+}
+
void laplaceSmoothing(GFace *gf)
{
v2t_cont adj;
@@ -252,16 +374,6 @@ void laplaceSmoothing(GFace *gf)
}
}
-double surfaceTriangleUV(MVertex *v1, MVertex *v2, MVertex *v3,
- const std::vector<double> &Us,
- const std::vector<double> &Vs)
-{
- const double v12[2] = {Us[v2->getIndex()] - Us[v1->getIndex()],
- Vs[v2->getIndex()] - Vs[v1->getIndex()]};
- const double v13[2] = {Us[v3->getIndex()] - Us[v1->getIndex()],
- Vs[v3->getIndex()] - Vs[v1->getIndex()]};
- return 0.5 * fabs (v12[0] * v13[1] - v12[1] * v13[0]);
-}
bool gmshEdgeSwap(std::set<swapquad> &configs, MTri3 *t1, GFace *gf, int iLocalEdge,
std::vector<MTri3*> &newTris, const gmshSwapCriterion &cr,
diff --git a/Mesh/meshGFaceOptimize.h b/Mesh/meshGFaceOptimize.h
index 67f7fa2f00..6c65013e6c 100644
--- a/Mesh/meshGFaceOptimize.h
+++ b/Mesh/meshGFaceOptimize.h
@@ -41,6 +41,7 @@ int edgeSplitPass(double maxLC, GFace *gf,
std::vector<double> &Vs,
std::vector<double> &vSizes ,
std::vector<double> &vSizesBGM);
+void removeFourTrianglesNodes(GFace *gf, bool replace_by_quads);
int edgeCollapsePass(double minLC, GFace *gf,
std::set<MTri3*, compareTri3Ptr> &allTris,
std::vector<double> &Us,
--
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