(Photo: Looking Glass Factory) Modern first-person shooters usually allow you to peek around corners, but the nearly 30-year-old Doom had no such feature. With the aid of a holographic display, however, corner peeking is now possible in id Software's classic game. As TweakTown reports, Twitter user Jan Kaiser shared a short video of Doom running on a holographic display (see below) developed by Looking Glass Factory. Kaiser walks up to a pillar in the game and then rotates the display to see what's hiding behind it. For playing the game it's unpractical, but as an experiment it's an impressive demonstration of the technology.