To attempt to describe how perspective steps in would but end in a boring wordiness.
I hesitate before applying hard and fast rules to the drawing of those exquisite curves, seen on the human figure. In the same way curves on a horizontal plane, such as a winding river seen from a height, or the track of a road across the valley, might be sketched by short lengths each length successively tending to a V.P. We only have to remember our practice with roads inclining up or downhill (see able to correct a faulty drawing by a few lines (as in Fig. If this were so, then in the foreshortened view each length would recede towards a new V.P. These drawings suggest that a foreshortened curve might in Nature be made up of a number of short straight lengths. The former shows how the curves of the bridge and railing would look the latter the curves of a causeway. WE will now consider curves in another way.