half subsampled sphere under curvature flow example

Polygon_mesh_processing/examples/Polygon_mesh_processing/curvature_flow_example.cpp

@@ -5,17 +5,43 @@
 #include <CGAL/Surface_mesh.h>
 
 #include <CGAL/Polygon_mesh_processing/smoothing.h>
+#include <CGAL/Polygon_mesh_processing/remesh.h>
 
 
 typedef CGAL::Exact_predicates_inexact_constructions_kernel K;
 typedef CGAL::Surface_mesh<K::Point_3> Mesh;
 
+typedef typename Mesh::vertex_index vertex_index;
+typedef typename Mesh::face_index face_index;
+typedef typename Mesh::halfedge_index halfedge_index;
+
+std::set<face_index> select(Mesh mesh, double x0)
+{
+    std::set<face_index> f_selection;
+
+    typedef typename boost::property_map<Mesh, CGAL::vertex_point_t>::type VertexPointMap;
+    VertexPointMap vpmap = get(CGAL::vertex_point, mesh);
+
+
+    for(face_index f : faces(mesh))
+    {
+        halfedge_index he = halfedge(f, mesh);
+        for(vertex_index v : vertices_around_face(he, mesh))
+        {
+            if(get(vpmap, v).x() < x0)
+                f_selection.insert(f);
+            continue;
+        }
+    }
+
+    return f_selection;
+}
 
 
 int main(int argc, char* argv[]){
 
 
-    const char* filename = "data/curved_polygon.off";
+    const char* filename = "data/sphere.off";
     std::ifstream input(filename);
 
     Mesh mesh;
@@ -24,13 +50,23 @@ int main(int argc, char* argv[]){
         return 1;
     }
 
+    std::cout<<"all faces: "<<faces(mesh).size()<<std::endl;
+    std::set<face_index> selected_faces = select(mesh, 0);
+    std::cout<<"selected faces: "<<selected_faces.size()<<std::endl;
 
+    CGAL::Polygon_mesh_processing::isotropic_remeshing(selected_faces, 0.05, mesh);
+
+    std::ofstream output;
+    /*
+    output.open("data/sphere_half-subsampled.off");
+    output << mesh;
+    output.close();
+    */
 
     CGAL::Polygon_mesh_processing::curvature_flow(mesh);
 
 
-
-    std::ofstream output("data/curved_polygon_smoothed.off");
+    output.open("data/sphere-half-subsampled_smoothed.off");
     output << mesh;
     output.close();