text: typedef Matrix<double,3,Dynamic> Matrix3Xd;
  Matrix3Xd M = Matrix3Xd::Random(3,5);
  Projective3d P(Matrix4d::Random());
  cout << "The matrix M is:" << endl << M << endl << endl;
  cout << "M.colwise().homogeneous():" << endl << M.colwise().homogeneous() << endl << endl;
  cout << "P * M.colwise().homogeneous():" << endl << P * M.colwise().homogeneous() << endl << endl;
  cout << "P * M.colwise().homogeneous().hnormalized(): " << endl << (P * M.colwise().homogeneous()).colwise().hnormalized() << endl << endl;