This was kind of interesting. Some illustration editing for my client in Florida, the problem was that the illustrations that the contractor uses to show houses had shingle roofs, and he only provides metal roofs now. At first I thought that I could probably just find a metal roof texture from a stock image site but, that didn’t turn out to be the case, so I made up a vector pattern for them, and then masked them onto the roofs. The edges didn’t look very good and you couldn’t tell the separate sections. So then I made up some little ridges for them.