从CGAL 3D网格物体生成获取-6.27744e + 66的顶点坐标：mesh_implicit_sphere示例

`````` vector<CGAL::Mesh_complex_3_in_triangulation_3<Tr>::Facet_iterator> Facets;
for (CGAL::Mesh_complex_3_in_triangulation_3<Tr>::Facet_iterator it = c3t3.facets_begin(); it!=c3t3.facets_end() ; it++)
{
Facets.push_back(it);
}
``````

``````CGAL::Mesh_complex_3_in_triangulation_3<Tr>::Facet_iterator fct = Facets[0];
cout << "Vertex 0 has coordinate: \n";
cout << fct->first->vertex(0)->point().x() << ", "
<< fct->first->vertex(0)->point().y() << ", "
<< fct->first->vertex(0)->point().z() << endl<<endl;

cout<< "Vertex 1 has coordinate: \n";
cout << fct->first->vertex(1)->point().x() << ", "
<< fct->first->vertex(1)->point().y() << ", "
<< fct->first->vertex(1)->point().z() << endl<<endl;

cout << "Vertex 2 has coordinate: \n";
cout << fct->first->vertex(2)->point().x() << ", "
<< fct->first->vertex(2)->point().y() << ", "
<< fct->first->vertex(2)->point().z() << endl<<endl;

cout << "Vertex 3 has coordinate: \n";
cout << fct->first->vertex(3)->point().x() << ", "
<< fct->first->vertex(3)->point().y() << ", "
<< fct->first->vertex(3)->point().z() << endl<<endl<<endl;
``````

（假设我正确理解了数据结构）fct指向包含（c，i）的std :: pair，这意味着：单元c中以fct表示的面和索引为i的顶点都属于单元c，它们满足： fct与顶点i相反。所以我的代码应该显示单元格fct-> first的顶点坐标（这是一个四面体，因此有四个顶点）。

Vertex3的坐标显然不正确，我搜索了这个问题，发现-6.27744e + 66通常来自喜欢访问未初始化矢量的事物。但是，即使是这种情况，我应该怎么做才能获得正确的值？或者，有人可以告诉我哪里出了问题吗？