What I don't like with "Unlimited Details" is that Dell refuses to say what the engine can't do yet. We know it's a work in progress. We (the internet) are excited about it because it's an experiment that's on scale with what we could expect from that branch of 3D graphics technology. Trillions of atoms, whatever. Show us what's still in progress because the internet is skeptical about this, this and this.

Hacking reflexion by duplicating the scene is a good way to start, because no one can say whether it's a good or a bad solution to a non-trivial problem - it gets the job done for now - but can you have multiple coexisting versions of the world? like a vertical mirror, a horizontal body of water and an underwater section?

To Dell: just stop handwaving the questions already, we get it that you ignored the state of the art and built your own thing, just tell us what it can't do yet, show us your current progress and you'll be met with much less skepticism, and even help, even if you keep your trade secrets, at least show us your specs! You won't be struck down by lightning if you talk - no one ever died from reinventing/copying the wheel and making it so good that the wheel can fly.