const float *m = &tracking_matrix.M[0][0];
const GL::Vector3 &base_look = base_camera.get_look_direction();
GL::Vector3 base_right = normalize(cross(base_look, base_camera.get_up_direction()));
GL::Vector3 base_up = normalize(cross(base_right, base_look));
const float *m = &tracking_matrix.M[0][0];
const GL::Vector3 &base_look = base_camera.get_look_direction();
GL::Vector3 base_right = normalize(cross(base_look, base_camera.get_up_direction()));
GL::Vector3 base_up = normalize(cross(base_right, base_look));