Although our eyes register perspective effortlessly, reproducing the effects of perspective (a sense of space and depth) in a drawing requires knowledge of how perspective works and a grasp of perspective drawing techniques. Mechanical perspective techniques use geometry to plot points on a drawing replicating more or less accurately what we see in three dimension on a two-dimensional surface. When drawing from life, accurate results are possible without using mechanical techniques if certain facts about how we see objects in perspective are considered.
THE HORIZON LINE
The horizon line is an imaginary horizontal line across the drawing paper that represents the eye level of the viewer. (Horizon line and eye level are equivalents ...