Although today’s generation of virtual reality devices and platforms has made technology more accessible, at least compared to its almost sci-fi stature years ago, it hasn’t exactly made it accessible to everyone, especially the budget constrained. Things like Google Cardboard and the Samsung Gear VR does significantly lower the barrier to entry, but it still requires an investment in a not so cheap premium smartphone. Although it dabbles more in augmented rather than virtual reality, Microsoft’s Research arm may have stumbled on part of the answer that will enable even mid-range smartphones to display VR content at a respectable framerate.
The problem with VR requirements is that it needs no small amount of CPU and GPU resources to render content on the fly. For behemoth computers, monster laptops, and high-end smartphones, that might not be a problem, though even smartphones sometimes struggle in that regard. Most smartphones below the $500 mark, however, aren’t as gifted when it comes to processors, making it difficult, almost futile, to use those for VR.
Those smartphones, however, do have more than enough data storage inside. This is where FlashBack puts the burden instead of on the CPU and GPU. What Microsoft Research did is to pre-render the VR content in all possible views that the user might walk or turn to. This process of creating a sort of cache isn’t exactly new but its application in this area definitely is.
That might also be an over simplistic way of explaining FlashBack’ technology. It isn’t simply a matter of rendering everything either. It also has to take into account the direction the user is looking at in order to select the next “piece” to put on the display and to warp it for each eye. There’s also the factor of compressing the rendered images so that they won’t take up too much space and then decompressing them later when needed. Compression does also take up CPU resources so if not done correctly, it could still end up adversely affecting the VR experience.
Microsoft Research claims that FlashBack produces 15 times lower latency, 100 times better energy efficiency, and up to 8 times the framerate. It’s not perfect though, as the researchers make no mention of real-time dynamic objects, which cannot be rendered before hand. FlashBack might be useful for pre-recorded content, but not for “live” events. Still, it’s a whole lot better than nothing.
SOURCE: Microsoft Research