Please see fig. 5.7，here is a two-point perspective scene looking across the ground plane to the horizon in the distance. The parallel lines of the railroad tracks and box converge at a vanishing point at the far right on the horizon. The other lines of the box that are parallel with the railroad ties share the same vanishing point on the far left. All of the lines of this scene converge at either the left or right vanishing point, or are vertical lines.