Tom Leathrum is Associate Professor of Mathematics at Jacksonville State University.In this third article in the series, I continue with the intent of encouraging working college math instructors to write their own applets, and to share their results with other developers, by providing mathematical incentives for learning how to write applets. This article continues the theme from the second article, looking at some of the interesting mathematics underlying three-dimensional graphics. The preceding article (see link at left) was about the linear and affine transformations that form the techniques for projecting a three-dimensional image onto the two-dimensional computer screen. Here I build on the terminology from that article (in particular, "view vectors") to consider finer geometrical problems involved in presenting surface graphs.