+ const GL::Vector3 &up_dir = base_camera.get_up_direction();
+ GL::Vector3 right_dir = normalize(cross(base_camera.get_look_direction(), up_dir));
+ GL::Vector4 columns[4];
+ columns[0] = compose(right_dir, 0.0f);
+ columns[1] = compose(up_dir, 0.0f);
+ columns[2] = compose(cross(right_dir, up_dir), 0.0f);
+ columns[3] = compose(base_camera.get_position(), 1.0f);
+ GL::Matrix matrix = GL::Matrix::from_columns(columns)*hmd_matrix;