As said, it's pretty much fake. It's the same mesh that's used two times in the scene. The second time with inversed culling and a tweaked rotation matrix (set to -1 at 1,1). There's a transparent plane between them to fake the floor. As said, lighting isn't correct with this approach. The mirrored dragon should actually be lit like the original one, but instead it's lit on its own. It should be possible to get this correctly by really seperating the two into two different worlds and rendering them both into one buffer, but for this benchmark, i haven't done it. The human eye is very forgiving concerning wrong lighting, so i think i can get away with this.