Google Cardboard

Google Cardboard is a virtual reality (VR) platform developed by Google for use with a head mount for a smartphone. Named for its fold-out cardboard viewer, the platform is intended as a low-cost system to encourage interest and development in VR applications. Users can either build their own viewer from simple, low-cost components using specifications published by Google, or purchase a pre-manufactured one. To use the platform, users run Cardboard-compatible applications on their phone, place the phone into the back of the viewer, and view content through the lenses. The platform was created by David Coz and Damien Henry, French Google engineers at the Google Cultural Institute in Paris, in their 20% 'Innovation Time Off'. It was introduced at the Google I/O 2014 developers conference, where a Cardboard viewer was given away to all attendees. The Cardboard software development kit (SDK) is available for the Android and iOS operating systems; the SDK's VR View allows developers to embed VR content on the web as well as in their mobile apps. Through March 2017, over 10 million Cardboard viewers had shipped and over 160 million Cardboard app downloads had been made. Following the success of the Cardboard platform, Google announced an enhanced VR platform, Daydream, at Google I/O 2016. Google Cardboard headsets are built out of simple, low-cost components. The headset specifications were designed by Google, which made the list of parts, schematics, and assembly instructions freely available on their website, allowing people to assemble Cardboard themselves from readily available parts. Pre-manufactured viewers were only available from third-party vendors until February 2016, when Google began selling their own through the Google Store. The parts that make up a Cardboard viewer are a piece of cardboard cut into a precise shape, 45 mm focal length lenses, magnets or capacitive tape, a hook and loop fastener (such as Velcro), a rubber band, and an optional near field communication (NFC) tag. Google provides extra recommendations for large scale manufacturing, and pre-assembled kits based on these plans are available for less than US$5 from multiple vendors, who have also created a number of Cardboard variations. Once the kit is assembled, a smartphone is inserted in the back of the device and held in place by the selected fastening device. A Google Cardboard–compatible app splits the smartphone display image into two, one for each eye, while also applying barrel distortion to each image to counter pincushion distortion from the lenses. The result is a stereoscopic ('3D') image with a wide field of view. The first version of Cardboard could fit phones with screens up to 5.7 inches (140 mm), and used magnets as input buttons, which required a compass sensor in the phone. An updated design released at Google I/O 2015 works with phones up to 6 inches (150 mm), and replaces the magnet switch with a conductive lever that triggers a touch event on the phone's screen for better compatibility across devices. Google provides three software development kits for developing Cardboard applications: one for the Android operating system using Java, one for the game engine Unity using C#, and one for the iOS operating system. After initially supporting only Android, Google announced iOS support for the Unity plugin in May 2015 at the Google I/O 2015 conference. Third-party apps with Cardboard support are available on the Google Play store and App Store for iOS. In addition to native Cardboard apps, there are Google Chrome VR Experiments implemented using WebGL; phones, including Apple's, that support WebGL can run Google's web experiments. A port of the Google Cardboard demonstration app to iOS was released at Google I/O 2015. In January 2016, Google announced that the software development kits would support spatial audio, a virtual reality effect intended to simulate audio coming from outside of the listener's head located anywhere in 3D space.