Google Cardboard is an inexpensive, fun and accessible virtual reality (VR) experience using your mobile phone. IIU created a prototype Google Cardboard App. Download it from App Lab (log-in required).
What is VR?
Virtual reality apps have the ability to effect users through rich, immersive experiences, which other platforms are not able to create. The public health field applies VR in training, learning and exposure therapy. Google Cardboard uses mobile technology to make the VR experience portable and inexpensive. It is virtual reality made simple.
*Scale of 0 to 5 stars, with 5 as the best rating
- Plan short VR experiences. The Google Cardboard viewer is not a head mounted device.
- Pair your viewer with the phone by scanning the viewer’s QR code. Using the wrong profile for your viewer can cause an uncomfortable VR experience and lead to eye strain, headaches and motion sickness.
- Use larger mobile screens, and use a viewer that can accommodate larger screens.
Samsung’s Gear VR is the other mobile VR product on the market. Gear VR requires a Samsung phone but only supports the higher-end models. Oculus Rift and HTC Vive are PC-based alternatives that are more expensive.
Ease of Use
Pros: Google Cardboard is easy to use. There is no controller. VR movement is based on head movement.
Cons: You may tire from holding the viewer and see marks where it rested on your face. You may experience motion sickness if the app has too much movement or distortion (e.g., distorted frequency at which frames are displayed due to using an older phone or if the app is performing suboptimally).
To use Google Cardboard you need:
- Smartphone (PC not needed)
- Cardboard viewer
- Google’s Cardboard app (for configuring viewer and accessing apps)
- A virtual reality app designed for use with Google Cardboard
Ease of Development
When designing standard mobile apps, developers have access to best practice guides such as Material Design. VR is still relatively new and there isn’t much information about standards and best practices. This makes development difficult. It’s up to the developer to create an app that will be visually appealing and easy to navigate while maintaining performance. One of the best references is Google’s Cardboard Design Lab App, which is open source and available on GitHub.
Developing a VR mobile app is less about writing code, and more about immersive graphics and audio. To develop mobile VR apps for Google Cardboard, it is very helpful to have 3D modeling experience. If not, you must download 3D objects online; some are free, but others can be expensive.
Software for Developing Google Cardboard Apps
- Native Android Software Development Kit (SDK)
– Familiar development environment for Android developers (Android Studio)
– Familiar language for Android developers (Java)
Cons: No 3D editor included in the development environment
- Cardboard SDK for Unity
Unity provides an easy-to-use interface for designing 3D applications. Unity natively supports Oculus, another VR product, but there are plug-ins for others, including Cardboard. IIU Cardboard app was developed using Unity.
– Simple to create a new Cardboard app
– Simple to modify an existing Unity project to include Google Cardboard
– Difficult to create visually appealing, high performance 3D objects. To create custom, 3D objects, you should probably use other 3D modeling tools. For IIU’s app, we found most of our 3D objects online (resources: Blender, Turbo Squid and Unity Asset Store).
– Performance issues are hard to overcome. With the standard Cardboard SDK setup, you must render the scene twice (once for each eye). Distortion correction must then be applied to offset the distortion from the lenses. Vertex displacement distortion correction is more efficient and leads to better performance. However, it involves writing custom shaders for each of your objects.
Resources Available for Developers
- Google Cardboard: API references exist, but the platform is undergoing active development and has not had a 1.0 release.
- Unity 5.2.1: This version of Unity is required for the Cardboard plug-in. Unity has much documentation on their website, but troubleshooting via sites such as StackOverflow can be challenging since this version is fairly new.
- Cardboard SDK for Unity: There is documentation of the Cardboard SDK, but not many examples. The SDK has also changed greatly since its start. This makes finding current information difficult.
- Download IIU’s Google VR app from App Lab (contact firstname.lastname@example.org for access)
- Demo – AOL’s VR summit for a virtual tour of several different cars
- Cardboard Design Lab App: Source code
- Cardboard SDK
- Vertex displacement blog post