Pretty much any set of 4 fp vectors that don&#x27;t share z coord will end up non-coplanar at some point (if you insist on going barycentric for texture iteration or if you plan on using halfplanes to do intersection or whatever). That&#x27;s why HW tends to use fixed point internal representation in such places. But yeah, whatever, it&#x27;s almost 1am and I shouldn&#x27;t be spending time convincing people online that GPU developers know a thing or two about GPU. :) But at the very least trust me on one thing: quads are dead. They&#x27;ve been dead for a long, long time now, low-end or high-end, quads make no sense at all.