this project covers a bit of the more _sane_ math behind this layered '3D' rendering method for complex 3D objects that don't require wide orbit angles
Update: This concept has been improved using my new "Reality" module, it does 3D processing for you. Nothing fancy, but works great for this. It is currently embedded in my new Demoscene: Goodbye. I'll unpack it and distribute it later as a plug-and-play kit.