COLLADAの穴(ポリゴン分割)

使われていないほうのポリゴン分割法
これでは穴があかない?

d:/COLLADA/viewer/Triangulation.c(308):

// Stupid triangulation
//
   Polygon->Triangulation = Cv_TriangleArrayAlloc(Polygon->NumOfVertexNodes-2);
   for(i=0;i<Polygon->NumOfVertexNodes-2;++i)
   {
    Polygon->Triangulation.Triangles[i].Vertex[0]=i;
    Polygon->Triangulation.Triangles[i].Vertex[1]=i+1;
    Polygon->Triangulation.Triangles[i].Vertex[2]=i+2;
   }      

こちらが本物のようです

d:/COLLADA/viewer/Triangulation.c(318):

NgonTriangulate(Polygon, Vertices, NumOfVertices);