Much like Google Cardboard enabled cheap and easy access to VR applications, an augmented reality (AR) kit called HoloKit is now providing low-cost access to the world of AR.
HoloKit made its debut this June at the Augmented World Expo USA, the world’s largest AR and VR conference and vendor exhibition. When paired with AR apps and a smartphone (currently supporting iPhone7 and Tango), HoloKit merges the real-world scene around the user with virtual entities — placing for example a rotating solar system overhead or a floating whale in one’s hand.
Botao Hu, founder of Silicon Valley based art & robotics studio Amber Garage, created HoloKit this year as an entry-level platform for people eager to experience AR. Compared to state-of-the-art AR gear like the Meta2 ($945) and HoloLens ($3000), HoloKit offers an unbelievably low price of US$30. The kit includes a cardboard viewer headset with a pair of cheap glasses (semipermeable membrane and Fresnel lens), and software.
“Nowadays, all other options in the mixed reality device market (Hu prefers the term ‘mixed reality’ over augmented reality) are either too expensive or just plain inaccessible. So we tried our best to design a mixed reality solution to provide a very high quality experience in visual effects, interaction, and perception technology while remaining affordable.”
Considering its performance, HoloKit seems a legitimate contender in the marketplace. The gear provides a 76 degree field of view (FOV), a little less than Meta2’s 90 degree FOV, but much larger than HoloLens’s 34 degree FOV. It performs with a mobile-phone based inside-out tracking, a method of position tracking commonly used in virtual reality or AR, and minimizes incongruity between the virtual entities and the reality scene.
“Keep your body down…turn you head around so you will get different views,” advised Hu as I used HoloKit to watch a cute Japanese cartoon character dancing in front of me. The integration between the virtual figure and the real environment behind it was visually acceptable, and so I did not experience the dizziness sometimes associated with AR.
HoloKit is not, however, a hands-free headset. The periscope-style design and top-mounting of the phone shifts the centre of gravity forward, and so users have to hold the gear at all times.
Unlike other AR/VR products, HoloKit’s TrackKit software code and DIY hardware instructions are open-sourced. This is to make mixed reality devices accessible to developers and to inspire people to create AR-based content. “HoloKit is our gift to the AR/MR industry,” says Hu. “You can think of this project as a social experimental project of academia and art.”
As a graduate from Tsinghua University and a Stanford University Master in artificial intelligence, Hu’s opinions on AR are influential in the Chinese AR community and beyond. His recent Zhihu (China’s Quora) post on “What is the difference between Microsoft’s HoloLens and Magic Leap?” earned almost 2,700 likes and over 100,000 views.
However, HoloKit’s release also triggered something of a backlash. After Chinese media praised the device with clickbait headlines such as: “A $30 HoloKit can beat a $3,000 HoloLens,” many on social media responded with incredulity. But Hu suggests those critics may have missed the point: “A low-cost component is not our core competence. The technology behind the software is the key.”
HoloKit uses a method of inside-out positional tracking called “monocular visual-inertial state estimator for mobile phones,” based on a rolling shutter camera with an inertial measurement unit (IMU) — a mobile sensor found in most smartphones.
The technique was first introduced by Professor Shaojie Shen of the Hong Kong University of Science and Technology (HKUST), who successfully proposed a robust estimator initialization algorithm to provide high-quality initial states for monocular visual-inertial systems (VINS). Hu’s role involved the practical application of the technique to AR.
HoloKit is quickly positioning itself as a market stimulator. Just as Google Cardboard increased access and interest in VR, so might HoloKit for AR.
Author: Tony Peng | Editor: Michael Sarazen | Producer: Chain Zhang