How to visualize a 3D polyhedron

[wyqsnddd]

I want to visualize a three-dimensional polyhedron through its vertices ( i.e., the V-representation ).

By investigating the support polygon, I noticed that we could feed vertices to a Polygon through the following snippet:

if(mDisplayPolygon)
  {
    mVertices->resize(poly.size());
    mFaces->resize(poly.size());
    for(std::size_t i=0; i < poly.size(); ++i)
    {
      const Eigen::Vector3d& v = axes.first*poly[i][0] + axes.second*poly[i][1]
                                  + up*mElevation;
      (*mVertices)[i] = ::osg::Vec3(v[0], v[1], v[2]);
      (*mFaces)[i] = i;
    }

    mPolygonGeom->setVertexArray(mVertices);
    mPolygonGeom->setPrimitiveSet(0, mFaces);
  }

This example only manages to visualize planar polygon no matter how much I tweak it. Could anyone give me a solution?