4 ms·

A trick i've heard at least one of the VR devices is doing isn't re-rendering the entire scene but since most of the movement is just head tracking, it renders

A trick i've heard at least one of the VR devices is doing isn't re-rendering the entire scene but since most of the movement is just head tracking, it renders a larger buffer and scrolls around in that buffer between frames to get a quicker response.

pfranz 10y ago
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.
- simcop2387 10y ago
  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
- renox 10y ago
  >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.
  - pfranz 10y ago
    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.
chrisseaton 10y ago
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!
- simcop2387 10y ago
  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.
hrnnnnnn 10y ago
The technique is called asynchronous timewarp https://developer3.oculus.com/blog/asynchronous-timewarp-examined/ https://developer3.oculus.com/blog/asynchronous-timewarp-exa...

pfranz 10y ago

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.

simcop2387 10y ago
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
renox 10y ago
>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.
- pfranz 10y ago
  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.

chrisseaton 10y ago

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!

simcop2387 10y ago
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.

hrnnnnnn 10y ago

The technique is called asynchronous timewarp https://developer3.oculus.com/blog/asynchronous-timewarp-examined/ https://developer3.oculus.com/blog/asynchronous-timewarp-exa...