Fumitaka Kotani writes from Japan:
Hello. I bought your book “Perspective! for Comic Book Artists” 3 years ago, and I have drawn many drawings using your guide book, but still I can’t understand the three-point perspective part, especially when you say “lines can be used as horizontal line and each grid can be used 3-ways”.
David Chelsea is reading:
Tubes: A Journey to the Center of the Internet
by Andrew Blum
In this section after you say that, you show 5 examples, bedroom,bathroom,laundry room, bed+bath+laundry room, and one more example (I can’t understand what I should say to describe 5th room). What I can’t understand is what you are trying to show in this part. All rooms look the same to me. Could you tell me what you intend to tell in this section?

Dear Mr. Kotani,
I agree that this particular section could have been clearer. What I meant by using each grid three ways, is that with three horizons and three vanishing points, there are three ways to position the grid with a horizon at top and a vanishing point at the bottom, and therefore three different angles of view one can get from a single drawing.(the green circle represents a 60° cone surrounding the center of vision). The drawing at bottom shows how I draw the same object from three different angles using the grid.
The idea is to save the extra work of constructing three-point perspective grids by using the same grid multiple ways. However, my newest book, EXTREME PERSPECTIVE!, eliminates the need to construct perspective at all, by including a disc of computer-generated grids which can be used a background element in digital drawing or printed out as hard copies to sketch over. The book has appeared in English, Korean, and Japanese editions.
Thank you for your letter,
David Chelsea.
This particular letter gave me an opportunity to try something new. Ordinarily I would have either drawn the diagram for him on paper or in Adobe Illustrator, which has infinitely stretchable lines and endlessly expandable visual area that make it ideal for perspective construction. However, instead I decided to draw it start to finish in Photoshop, which is the application I use for most digital art. I will outline the steps I used in a later post.