A while back I was working on a project for a client when I ran into some issues trying to implement a semi 3d design concept. When I did the sketches in photoshop I thought it was gonna be a breeze to implement, but after the design was approved by the client and the deadline was set, I really ran into some trouble. I can´t really go into specifics about this particular project, but the bottom line was that I needed to apply the rules of 3d perspective in some situations, while bending the same rules to fit a dynamic two dimensional layout in other. The result I was looking for just couldn´t be achieved by applying the built in 3d features of Flash 10, or any of the other open source 3d libraries like papervision3d or away3d. At least not without having a great deal of in depth knowledge of how these libraries work from the ground up. That is why I decided to get my hands dirty with the basics of 3d math.