本例子說明以下問題：
1.如何聲明你自己的mesh類型MyMesh
2.如何向mesh對象添加節點和麪
3.如何通過IO函數將mesh寫至硬盤
利用OpenMesh進行開發，首先需要定義你自己的mesh類型MyMesh。OpenMesh支持一般的多邊形mesh和特殊的三角面mesh。在這個例子中，我們希望使用留個四邊形建立一個立方體，所以，我們選擇多邊形mesh。
OpenMesh也支持不同的mesh內核，指明所有的節點、邊緣和麪在內部如何存儲，這樣，內存必須提供數組形式的接口。本例中，我們使用內建的ArrayKernel。OpenMesh/src/OpenMesh/Core/Mesh中預定義了TriMesh/PolyMesh及其內核，我們使用PolyMesh_ArrayKernelT模板。
#include <OpenMesh/Core/Mesh/PolyMesh_ArrayKernelT.hh>
typedef OpenMesh::PolyMesh_ArrayKernelT<>MyMesh;
現在，我們已經聲明瞭我們自己的mesh類型MyMesh，下面，爲了建立立方體，我們還需要添加8個節點和6個四邊形，使用add_vertex函數實現。這個函數輸入座標，輸出爲節點句柄。由於需要使用它們來指定表面，我們使用數組存儲所有的句柄。
vhandle[0] = mesh.add_vertex(MyMesh::Point(-1,-1, 1));
vhandle[1] = mesh.add_vertex(MyMesh::Point(1, -1, 1));
vhandle[2] = mesh.add_vertex(MyMesh::Point(1, 1, 1));
vhandle[3] = mesh.add_vertex(MyMesh::Point(-1,1, 1));
爲了在mesh中添加表面，我們不得不建立一個vector，來存儲面的節點的索引。這個vector將被傳遞給add_face函數。下面的代碼使用前四個節點創建表面。
std::vector<MyMesh::VertexHandle>face_vhandles;
face_vhandles.clear();
face_vhandles.push_back(vhandle[0]);
face_vhandles.push_back(vhandle[1]);
face_vhandles.push_back(vhandle[2]);
face_vhandles.push_back(vhandle[3]);
mesh.add_face(face_vhandles);
面的方向由vector中存儲節點的順序指定：如果你從面的“前面”看，節點排列順序是逆時針的。創建完所有的6個面後，我們希望將我們剛剛創建的mesh進行標準化輸出。OpenMesh在命名空間OpenMesh：：IO中提供了一些基本的輸入/輸出函數。
if ( !OpenMesh::IO::write_mesh(mesh,"output.off") )
使用OpenMesh：：IO前，應當首先包含MeshIO.hh文件。.
#include <OpenMesh/Core/IO/MeshIO.hh>
#include<OpenMesh/Core/Mesh/PolyMesh_ArrayKernelT.hh>
完整的代碼如下：
/*========================================================================= *
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#include <iostream>
// -------------------- OpenMesh
#include <OpenMesh/Core/IO/MeshIO.hh>
#include<OpenMesh/Core/Mesh/PolyMesh_ArrayKernelT.hh>
// ----------------------------------------------------------------------------
typedef OpenMesh::PolyMesh_ArrayKernelT<>MyMesh;
//----------------------------------------------------------------------------
// Build a simple cube and write it tostd::cout
int main()
{
MyMesh mesh;
// generate vertices
MyMesh::VertexHandlevhandle[8];
vhandle[0] = mesh.add_vertex(MyMesh::Point(-1,-1, 1));
vhandle[1] = mesh.add_vertex(MyMesh::Point(1, -1, 1));
vhandle[2] = mesh.add_vertex(MyMesh::Point(1, 1, 1));
vhandle[3] = mesh.add_vertex(MyMesh::Point(-1,1, 1));
vhandle[4] = mesh.add_vertex(MyMesh::Point(-1,-1, -1));
vhandle[5] = mesh.add_vertex(MyMesh::Point(1, -1, -1));
vhandle[6] = mesh.add_vertex(MyMesh::Point(1, 1, -1));
vhandle[7] = mesh.add_vertex(MyMesh::Point(-1,1, -1));
// generate (quadrilateral) faces
std::vector<MyMesh::VertexHandle>face_vhandles;
face_vhandles.clear();
face_vhandles.push_back(vhandle[0]);
face_vhandles.push_back(vhandle[1]);
face_vhandles.push_back(vhandle[2]);
face_vhandles.push_back(vhandle[3]);
mesh.add_face(face_vhandles);
face_vhandles.clear();
face_vhandles.push_back(vhandle[7]);
face_vhandles.push_back(vhandle[6]);
face_vhandles.push_back(vhandle[5]);
face_vhandles.push_back(vhandle[4]);
mesh.add_face(face_vhandles);
face_vhandles.clear();
face_vhandles.push_back(vhandle[1]);
face_vhandles.push_back(vhandle[0]);
face_vhandles.push_back(vhandle[4]);
face_vhandles.push_back(vhandle[5]);
mesh.add_face(face_vhandles);
face_vhandles.clear();
face_vhandles.push_back(vhandle[2]);
face_vhandles.push_back(vhandle[1]);
face_vhandles.push_back(vhandle[5]);
face_vhandles.push_back(vhandle[6]);
mesh.add_face(face_vhandles);
face_vhandles.clear();
face_vhandles.push_back(vhandle[3]);
face_vhandles.push_back(vhandle[2]);
face_vhandles.push_back(vhandle[6]);
face_vhandles.push_back(vhandle[7]);
mesh.add_face(face_vhandles);
face_vhandles.clear();
face_vhandles.push_back(vhandle[0]);
face_vhandles.push_back(vhandle[3]);
face_vhandles.push_back(vhandle[7]);
face_vhandles.push_back(vhandle[4]);
mesh.add_face(face_vhandles);
// write mesh to output.obj
try
{
if ( !OpenMesh::IO::write_mesh(mesh,"output.off") )
{
std::cerr << "Cannot write mesh to file'output.off'"<< std::endl;
return 1;
}
}
catch( std::exception& x )
{
std::cerr << x.what() <<std::endl;
return 1;
}
return 0;
}