Dividing and Multiplying Space in Perspective

Divide a surface in half (and again)

Draw both diagonals of a wall, a door or any rectangle in perspective. They cross at its true centre — which is not halfway across on paper, because the far half is foreshortened. A vertical through that point splits the wall into two equal halves; repeat in each half for quarters, eighths and so on.

Multiply: repeat equal spaces into the distance

1. Draw guide lines. Draw the top and bottom of the row of objects to the vanishing point, plus a line exactly halfway between them.
2. Draw the first two objects. Place the first two posts by eye; their gap sets the spacing.
3. Draw the diagonal. From the top of the first post, draw a straight line through the midpoint of the second post.
4. Find the next post. Where the diagonal hits the bottom guide line is the base of the third post.
5. Repeat. Continue from the top of post 2 through the middle of post 3, and so on.

Artist Paul Heaston's short video of this trick for railway ties spread widely online — it works for ties, columns, windows, street lamps and floor tiles alike.

Floor tiles

For a tiled floor, draw one row of tiles along the front, then a single long diagonal from a front corner toward the back. Wherever it crosses each depth line marks where the next row of tiles begins. This is the "diagonal measuring line" method used in many drawing courses.

Uneven spacing

For a pattern like door–window–window, mark the real proportions along a horizontal measuring line at the front, run each mark to a vanishing point and transfer them back with a diagonal.