Suppose you want to draw in perspective a row of posts of equal height spaced equally like this:
First we will follow the practice common in art and architecture of assuming that in our drawing the vertical directions remain vertical. So the first two posts look like this:
The Problem
The Problem is Simple. Given this much of the perspective drawing, how do you draw accurately the rest of the posts? You can stop when you have drawn half the posts if you get tired, but they should be spaced correctly as placed by a central projection.