Schematic view of the geometry of the Serpens filament. The left panel gives a perspective view of its 3D geometry, and the right panels represent the projection on to the x-y, x-z, and y-z planes. The midplane and its parallel surfaces have the same distances to observers, and the line of sight is along the z direction. The local velocity gradients that are associated with blueshifted and redshifted flows are indicated by the blue and red arrows, while the magnetic field is indicated bygreen dashed lines.