How does one measure off rows of windows on a building or skyscraper in three-point perspective? It's easy enough using vertical and horizontal scales of equal distance to measure in one and two-point, but that method doesn't seem to work for three-point. All the perspective books I own somehow avoid the issue of measuring in three-point perspective.
I asked this question in another forum and was told to "eye-ball" it, but I would rather prefer to do it the correct way. So, how's it done?