How?Many phones the ability to output a copy of their screen to an external monitor. Two prevalent standards to do so are MHL (Mobile High-definition Link) and SlimPort. Both provide a copy of the phone display to an external HDMI connector. For this purpose of driving a VR headset, both should be fine, and the choice depends on which method your phone supports. For example, for an LG G3 phone, this SlimPort adapter worked well for us.
Now that you have this in HDMI format, typically at 1920x1080, you'll want a VR headset that supports this resolution. This is a bit more tricky than it sounds because several 1080p headsets expect 1080x1920 portrait mode video format and thus are incompatible with the smartphone output. However, headsets such as the OSVR HDK and the professional Sensics dSight and zSight 1920 can accept standard 1080p landscape-mode video and display the phone output right away.
This approach is not limited to phones. Tablet such as the Google Nexus 7 also features a SlimPort output.
Why?Obviously, phones or tablets have access to content that would be interesting to watch using a VR headset. For instance, www.youtube.com/3d has plenty of side-by-side movies that are suitable for a VR headset.
Headsets that accept standard 1920x1080 video typically have on-board video processing. This can also be used to turn a regular image into a side-by-side image by replicating it across both sides of the display. This can be very useful to experience non-3D content or standard applications.
One could also imagine a game being run on the phone and the headset being used as a display device. A Bluetooth motion tracker could be installed on the headset and communicate with the phone, or if you have the appropriate software installed on the phone (such as the OSVR software framework), you could communicate with the headset's USB tracker.
The alternative, of course, is to wear the phone on your head with the appropriate adapter - whether the Samsung Gear VR, Google Cardboard, Zeiss VR One and so forth.
What are the advantages of wearing the phone on your head?
- No cables required.
- No need to purchase SlimPort or MHL adapter.
- Can use phone camera within application.
- Can be used with any compatible phone or tablet
- Reduces weight - no need to wear the battery, the phone case or other unnecessary components on the head. This is especially valuable with a tablet.
- Allows using the phone's touch screen.
- With the right headset, can also experience non-3D content or regular applications.
- Can quickly connect and disconnect if required.