Cartoon showing the sensitivity of the reconstructed 3D magnetic field. The Galactic magnetic field, the Orion A cloud, and the reconstructed field are shown with the red vector, bent gray cylinder, and the blue 3D B (1) arrow, respectively. Top panel: Projection onto the plane of the sky. Middle and lower panels: Different viewing angles of the cloud. The black arrow in the middle panel illustrates the direction of rotation to obtain 3D B(2), which remains consistent with the observations and is semi-convex from the observer’s point of view.