Google Cardboard

Virtual Reality — On a Budget

Innovation Time Off (ITO) is a policy championed by Google in which all engineers are encouraged to spend 20% of their work time on personal technology projects[1]. Though projects developed during Innovation Time Off don’t usually have immediate revenue potential, some of Google’s current flagship services such as AdSense, Gmail and Google News originated from an employee’s unstructured brainstorming[2]. Google Cardboard, the brainchild of engineers David Coz and Damien Henry, is the latest ITO-inspired Google innovation[3]. I’ve had a chance to experience the budget-friendly take on virtual reality afforded by Google Cardboard, and I’m convinced that Google has a future winner on their hands.

What is it?

The original Google Cardboard hardware was introduced at the Google I/O developer’s conference in June 2014. Consisting of a nondescript perforated sheet of cardboard, a rubber band, two pieces of Velcro and a set of optical lenses, Google Cardboard is entirely reliant on a compatible Android smartphone for any degree of functionality. Since Google only produced a limited supply of “official” Cardboard kits for software developers, I purchased an unofficial copy from the aptly named www.unofficialcardboard.com. From what I can tell, the unofficial cardboard product is virtually identical to the genuine product. In any case, the magic behind Google Cardboard rests in the software and idea, not the hardware execution.

In essence, Google Cardboard is a headset mount for a smartphone. When fitted properly, my smartphone is mounted about two inches from my eyeballs, with its LCD screen filling all but the most extreme boundaries of my peripheral vision. The screen is brought into focus by a pair of lenses that focus each eye on the corresponding half of my 4.7 inch smartphone screen. When I look at my smartphone’s homescreen through the Google Cardboard viewing windows, all I see is a cross-eyed, albeit focused, mess. Google Cardboard only works with compatible apps that support stereoscopic display software.

Stereoscopic Imagery

3-D stereoscopic imagery has been around for at least a century. Each stereoscopic implementation works towards the same goal — presenting each the left and the right eye a slightly different perspective-shifted 2 dimensional image to trick the brain into interpreting 3-dimensional geometries[4]. However, implementations of stereoscopic viewing experiences have been lackluster. Red/blue tinted 3-D glasses suffer from color distortion, polarized 3-D movie glasses suffer from poorly lit images and Nintendo’s glasses-free 3-D viewing experience on the 3DS suffered from a narrow viewing angle for a proper 3-D image[5]. On the other hand, the stereoscopic imagery experience offered by Google Cardboard is natural and polished — the powerful LED screen backlight renders bright and accurate colors while the contoured head mount and anchored lenses make the 3-D image appear unforced and realistic.

The Experience

Instead of merely allowing for 3D moving pictures, Google Cardboard establishes itself as a virtual reality headset by incorporating the gyroscopic sensors present in most smartphones today for an interactive experience. In Google’s official suite of mini-applications for Google Cardboard, I picked a demonstration involving a cartoonish forest scene[6]. By physically turning my head and looking up or down, my perspective is instantaneously shifted on the screen. Combined with sound effects and stereoscopic 3-D vision, there is theoretically no difference in between the stimuli fed to my brain in virtual and actual reality. In practice, however, two technical limitations hold Google Cardboard back from being a truly immersive virtual reality experience: resolution and latency.

Resolution Limitations

My android smartphone has a screen resolution of 1920 by 1080 pixels, and, in practice, on-screen images appear to be indiscernible from reality as far as resolution goes[7]. However, when Google Cardboard allocates each half of my smartphone screen to be blown up to fill my entire field of vision, each individual pixel becomes noticeable — after all, the lenses literally act as magnifying glasses. Virtual reality as viewed through Google Cardboard feels like using a first-generation smartphone or non-HD television — imagery feels like computer graphics instead of what we would associate as reality. It’s like I’m viewing everything through a screen door: there’s a telltale pixelated quality to textures and images.

Latency Limitations

While it would be an exaggeration to say that there is a noticeable delay between head movement and on-screen perspective change within Google Cardboard apps, movement is not quite instantaneous either. After extended (read: five minutes) use of Google Cardboard, I began feeling slightly nauseous: my cerebellum knows that visual feedback from turning my head should be instantaneous, so even the tiniest delay makes the entire experience feel “off.” John Carmack, a lead developer for the virtual reality technology company Oculus VR, explains that approximately 20 milliseconds is the latency threshold at which the human brain senses that something is amiss[8]. With more intensive virtual reality applications, my (high end!) smartphone regularly renders below 30 frames per second, which corresponds to a nausea-inducing 30-40 millisecond latency.

The Future of Virtual Reality

Google’s proof-of-concept with Google Cardboard is an innovative way of introducing virtual reality to anyone with $10 and a compatible Android smartphone. However, it seems like the technical limitations of a smartphone-powered virtual reality experience make full immersion impossible. Companies such as Oculus VR are developing prototypes that leverage integrated hardware-software sensors and microchips to bring low-latency, fully immersive virtual reality to the consumer. These headsets, such as the Oculus Rift, will be expensive and specialized — that’s the drawback of functional hardware design. However, Google Cardboard and other smartphone-powered headsets will allow any prospective early adopter to experience virtual reality without an expensive barrier to entry. While not a final product by any means, Google Cardboard further supports the idea of a smartphone truly becoming an all-purpose device.

[1] http://www.forbes.com/sites/johnkotter/2013/08/21/googles-best-new-innovation-rules-around-20-time/

[2] http://www.nytimes.com/2007/10/21/jobs/21pre.html

[3] https://cardboard.withgoogle.com/

[4] http://whatis.techtarget.com/definition/stereoscopy-stereoscopic-imaging

[5] http://www.eurogamer.net/articles/digitalfoundry-2014-new-nintendo-3ds-review

[6] https://play.google.com/store/apps/details?id=com.google.samples.apps.cardboarddemo&hl=en

[7] http://www.htc.com/us/smartphones/htc-one-m7/

[8] http://oculusrift-blog.com/john-carmacks-message-of-latency/682/