I explain more about walls, floors, and ceilings, as well as other related topics. This is a continuation of my first video on walls/floors/ceilings [https://youtu.be/UnU7DJXiMAQ], as this video contains additions, clarifications, and corrections to that video. Note that since that first video covered all the basics, it's become much easier and efficient for me to discuss related topics that rely on that information.