That only works for very, very minimal differences. It's the Oculus that does this. It guesses where your head will be, renders the scene at that location, and distorts the image slightly to match its guess vs reality. It also introduces a bit of softness, but seems to work pretty well. But it does re-render the whole image each frame.

I wonder if it does it to create intra-frame changes from rotation and/or motion of the head. If it does then that could help a lot with the experience

>It's the Oculus that does this.

And the PS no? I think that all the VR system will (optionally) do this to reduce the processing power needed.

I have no idea about the PSVR. It's probably the VR device I've heard the least about (technically). I own one, and it works pretty well, but I don't know much about it.

From my understanding this won't do anything to reduce power processing, it's all about reducing latency. That final transform happens at the last moment, with the most up-to-date head tracking information. I kind of figured it happened in the headset hardware itself in order to reduce the latency as much as possible.

The technique is called asynchronous timewarp

https://developer3.oculus.com/blog/asynchronous-timewarp-exa...

That would only work if the scene was a single flat surface and you were only moving in parallel to it. If you were doing that you may as well not use VR and just look at a normal monitor. Otherwise it wouldn't match your motion, which is the problem you're trying to solve in the first place!

Actually moving parallel to it would make the artifacts worse as it'd distort the projection based on distance (i.e. parallax). With a rotation if you're rendering it onto a sphere, doing that rotation will have a very little amount of distortion from it comparatively. It still needs to be rerendered to be correct but this can allow for better intra-frame changes (say game runs at 60 hz, and you need 120hz) with less computation. As a sibling (to you) commenter pointed out, this will make the image slightly "fuzzy" or softer because you end up moving the image on a fractional amount of pixels. As I understand it though, that extra intra-frame can mean the difference between some people getting a VR migraine or not.