You need quite a powerful GPU to do VR on a PC. But mobile phones (Gear VR, Google Cardboard) can do VR with much less graphics horsepower because the entire hardware stack can be controlled. The path from the motion sensors to rendering the VR scene on a phone is very fast.
You still need a powerful mobile GPU to do good 3D graphics but actually rendering but the VR part doesn't require as much.
> But mobile phones (Gear VR, Google Cardboard) can do VR with much less graphics horsepower because the entire hardware stack can be controlled.
No, they just generally have a much lower expectation to meet of the graphics fidelity produced.
> The path from the motion sensors to rendering the VR scene on a phone is very fast.
What would you say slows this down on a modern PC? Is it the connections to the headset? Is it the OS?
> You still need a powerful mobile GPU to do good 3D graphics but actually rendering but the VR part doesn't require as much.
Why would this be different between mobile and a normal PC? Both need to render a image at 60fps (or probably 90), for two viewpoints, regardless of if it is driven by a PC or a mobile. What is different?
The killer issue for VR is latency. If you have a lot of latency between the motion and the rendering people will throw up. And it's much easier to control that latency on a mobile phone platform than on a PC.
John Carmack has written extensively on this subject if you are interested. One example he gives is that graphics card drivers will aggressively buffer draw commands to increase performance and image fidelity at the cost of latency. In a normal game that's no problem but that is terrible for VR. Even a little bit of delay between movement and the display reflecting your new position is nauseating.
On mobile, the latency can be highly controlled from the driver, OS, and custom hardware even while sacrificing other performance.
Right, so the "fight" is between more raw power on on a PC vs more direct driver access on mobile.
Except that only holds up if you consider the headset a primary gaming device.
Usually people expect a certain graphical fidelity from PC or console games, so either we have a world with only consoles (which have standardized hw/sw stacks like mobile) and mobiles are gaming devices or we have one that is just like it has been for the last 10-15 years. Which do you think is more likely?
>But mobile phones (Gear VR, Google Cardboard) can do VR with much less graphics horsepower
I'd say mobile phones can do much less VR with much less graphics horsepower. I tried both Oculus, Vive and Cardboard, and the last was terribly underwhelming after seeing proper VR solutions.
You still need a powerful mobile GPU to do good 3D graphics but actually rendering but the VR part doesn't require as much.