When 3-D printing first emerged, it inspired visions of a world where we could print any real-life object with the click of a button. And hype hasn't yet subsided...just click over to HBO's hit show Westworld, where the technology plays a key role in a futuristic vision of near-real robotic human (and animal) "hosts" designed for recreation. In the real world, however, 3-D printing is still very much in its evolutionary phase.