The fold-your-own Google Cardboard virtual reality headset has hit the half-a-million units shipped mark. And to mark the occasion, there's now an official Cardboard SDK for both Android and Unity. The SDK is designed to make it easier to build apps for Cardboard, taking care of the heaving lifting for things like head-tracking, lens distortion, and side-by-side rendering.
In addition, Google's also pushing out updated open-source specs for Cardboard headsets. The new specs are designed with varying cutting tools in mind, so you can easily get one that's meant for chopping things out from a huge stack of cardboard with a laser or it's just you with a utility knife and a single sheet of that corrugated paper board.