Evaluation of Mobile VR Solutions
During the evaluation phase of our work with East Carolina University on Project I4, the development team had to balance portability, quality and scalability across devices. We evaluated both tethered headsets (wired to the display port and/or USB of a host computer) and untethered headsets that run the entire VR experience on an onboard Android operating system. We selected Unity for its cross-platform ease of use and the team's deep experience with it.
The Oculus Quest has two 1600×1440 OLED screens running at 72 frames per second; by default, apps render to 1216×1344 eye textures. Like the Oculus Go, Quest uses an open-ear audio solution that pipes sound through the straps without covering the ears, and it also supports regular headphones. Its Snapdragon 835 chipset includes an Adreno 540 GPU at 710 MHz — a "binning" or tiled GPU that cuts the scene into a grid of tiles and renders each in sequence. Quest comes with 4 GB of memory, 2.75 GB of which is available to applications, and supports OpenGL ES 3.1 and Vulkan, which is a plus if we need advanced graphical features later.
We ultimately selected the Quest over the Go, or tethered solutions like the Vive or the upcoming Reverb, because it matched our needs for portability, quality and scalability. Portability was a given with the untethered design, and future hardware was likely to continue the trend. (We did find you can tether over USB-C to borrow a PC's GPU for extra visual punch, but that wasn't essential for this project.) The Quest's quality was more than adequate given the prototypes we built, and performance tests with multiple realistic scenes and animated characters held a stable 72 fps to keep users comfortable.
The final consideration was the people using the simulation. Our audience was not gamers, and mostly not experienced VR users. The design and flow of the experience had to account for that, balancing in-headset tutorials with pre-headset videos and discussion to teach the basics of virtual reality.