This week’s posting will be a very straight forward one.  Andrew Loomis’ third example in this section of Successful Drawing shows how the artist can use diagonals to create a checkerboard pattern in perspective.  This is useful for drawing repeating windows of uniform size, or bricks on a wall receding into the distance.  The example I will use is of a brick wall.

This is how it is done.

1. Create the perspectival plane which will be the brick wall.  Locate the Vanishing Point. Use any angle that you wish.
2. Divide the near vertical edge of the wall into equal separations.  The size you choose will represent how tall each brick will be.
3. Cast lines to the V.P. from the points indicated by the vertical spacing you created with the brick heights in step 2.  We shall call these lines the Brick Height Lines.
4. Here is where the diagonal comes in.  Cast a diagonal line from corner to corner on the face of the wall you are drawing.  The diagonal can go up or down. 
5. Where the diagonal (blue line in this example) crosses each of the multiple Brick Height Lines, draw a 90 degree vertical from the bottom of the wall to its top.
6. Repeat this at each crossing point, and the wall plane will be divided perfectly in perspective.
7. Erase the guide lines to reveal the wall.

Uses

This method can be used for drawing multiple series of drawers, such as in a morgue or a bank vault, architectural or vehicular designs, it can be used as a grid for aiding the placement lettering or imagery on signage, or as a way of drawing bricks and checkers.

The diagonal is the key to being able to measure the depth of the sections.  Next week, I will explain how the diagonal can help in measuring, and thus correctly drawing a repeating panel section in perspective.

Thanks for reading, and I hope to see you next posting.