3D orientation of the Orion A GMC in Galactic cartesian coordinates (X positive toward the Galactic center, Y positive toward the Galactic east, Z positive toward the Galactic north). The orange dots represent the mean positions of YSOs per Δl (see Fig. 3), while only using those on top of high column-density. The gray shaded area shows an idealized 3D cloud shape in each projection at A_{K, Herschel}  ≳ 0.57 mag (A_V ≳ 5 mag), assuming a symmetric cylindrical shape, meaning that the filament is as deep as it is wide in the sky. For orientation, the black arrows indicate the line-of-sight from the Sun. Each arrow points toward (l, b)=(211.0, −19.5) plotted from d = 380 pc to 390 pc.