I'm using Python3 and Pygame, and so far have completed chapter 10 where you make the patterns. I'm having an issue with the checkered pattern on planes though. As you can see from the two images, the only difference is whenever I use a checkered pattern on a plane, it's a bit noisy. But it's not noisy on a sphere. I don't know if this has to do with an epsilon issue or not. Just wondering if someone has any ideas. Thanks and I'm loving the book!