# INSTRUCTIONAL DRAWINGS IN RE-RE-REVERSE

My name is Paul Peng and my algorithm is better than yours. Observe:

To create a drawing:

1. Draw a land-shaped region (i.e., fairly random) on the piece of paper using an erasable material. You may use the edges of the paper or pre-existing lines as part of the edge of the region
2. To fill in this region, follow instructions below on how to properly fill in a region
3. One the region has been completely filled in, erase the outer edge of the region
4. Repeat steps 1-3 about two more times, although more if desired

To properly fill in a region:

1. If you feel that the region you are filling in is already as full as it needs to be in the context of any larger regions it resides within, stop.
2. If the region that you are filling in has straight edges other than those defined by the edge of the paper or any straight lines from other regions of which the region you are filling in is not a part of (i.e., your region is part of a larger one), you are to draw a line splitting the region in two that is roughly parallel, but not necessarily exactly parallel, to one of the straight edges.
3. If your region contains no straight edges other than those defined by the edge of the paper or unaffiliated regions (i.e., your region is not part of any larger one (i.e., you just started filling this region in)), you are to draw a line splitting the region in two in any direction you want, preferably one that has not been used in any other part of the drawing before.
4. Regardless of whether you have drawn a line described by step 2 or step 3, you are to select a random point on the line and draw another line, roughly perpendicular but not necessarily exactly perpendicular to the previously drawn one, from that point to the edge of the region.
5. These two lines will have divided your region into three parts. These three parts can be considered regions in their own right, although part of the larger region, and are to be filled in with these directions recursively called upon them until they or all of the smaller regions they create are sufficiently full as expressed in step 1 of this sub-procedure.

Sexy, no? Here is a drawing my roommate created using these instructions. He studies mathematics and music technology and is not very good at drawing at all.

His last region was the rightmost one. You can kind of tell.

In addition to his contribution, I also gave a test run of my drawing algorithm to see how effective it was at replicating the original drawing. Here is mine:

i drew this based on an earlier version of the algorithm so instead of land-shaped regions I just had blobs. :/

Overall it turned out pretty good four and a half hearts out of five <3<3<3<3<

# One comment

1. paulpeng

If you are viewing this on a bad screen I invite you to look at the drawings at an angle since you get all sorts of cool jpeg artifacts that I never noticed before.