The person who invented this way of inventing this 3D Penrose Triangle was Ulrich Schwanitz, who sent me some emails asking me to correct my post (which I did as soon as I got back to my laptop after a day at a conference), but he sent a much more substantial email to Thingiverse, a service that hosts 3D models: in this email, Mr Schwanitz accused Tchoukanov of violating his copyright and demanded that the model be removed from the Internet in accord with the Digital Millennium Copyright Act.
In so doing, Mr Schwanitz has become the first person in history to threaten Thingiverse with a copyright lawsuit.
I write books. My latest is a YA science fiction novel called Homeland (it's the sequel to Little Brother). More books: Rapture of the Nerds (a novel, with Charlie Stross); With a Little Help (short stories); and The Great Big Beautiful Tomorrow (novella and nonfic). I speak all over the place and I tweet and tumble, too.