void draw_2d_fit(RendererViewport r, OpticalSystem system, bool keep_aspect)
        {
            Vector3Pair b = system.get_bounding_box();

            r.set_window(Vector2Pair.from(b, 2, 1), keep_aspect);
            r.set_camera_direction(Vector3.vector3_100);
            r.set_camera_position(Vector3.vector3_0);

            r.set_feature_size(b.v1.y() - b.v0.y() / 20.0);
        }