NThe latest update to SteamVR adds asynchronous reprojection for Nvidia GPUs. Similar to Oculus’ asynchronous timewarp, it mitigates unwanted ‘judder’ when the hardware fails to maintain 90fps.

Available via the SteamVR Beta since October 25th, asynchronous reprojection is a much-awaited feature, particularly for HTC Vive users. The idea is to maintain smooth motion on head orientation when the framerate drops below 90fps. Previously, Valve’s universally-compatible solution was ‘interleaved reprojection’, which capped the rendering at 45fps, reprojecting every other frame to make head rotation still ‘feel’ like 90Hz, but having a negative impact on positional movement and animation. With asynchronous reprojection, a slight drop in performance will not trigger this halving of framerate, instead picking up the previous frame and displaying it again, shifted to match the updated orientation data. The overall result is a major improvement to smoothness and comfort, as situations where framerate is fluctuating just below 90fps are very common.

Oculus Rift owners have been enjoying the benefits of an asynchronous reprojection solution (called asynchronous timewarp) since its launch in March, which already works across all applications (including when using the Rift in SteamVR mode), so there is no impact on Rift users with this update. It’s great to see Valve beginning to offer a similar technology, but they still need to expand the support to AMD cards in order to match Oculus’ complete solution.

Oculus Touts New VR Rendering Feature, Valve Calls It an "Ideal Safety Net"

Valve has been somewhat reluctant to enable more advanced reprojection solutions, having prioritised ‘adaptive quality’ (e.g. dynamically adjusting resolution and anti-aliasing) to hold framerate, as this caters to a wider range of hardware and other operating systems. Oculus, on the other hand, are Windows only, and have gone a step further in performance mitigation, having recently introduced ‘Asynchronous Spacewarp’, which deals with positional and animation judder that is still apparent with conventional asynchronous reprojection. This has effectively reduced the minimum requirements for VR rendering, as the Rift now works comfortably at 45fps. We can expect to see a form of ‘spacewarp’ from Valve too, as it is not only an effective safety net for performance drops, but it is also important to reduce the cost of entry to VR in general.

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The trial version of Microsoft’s Monster Truck Madness probably had something to do with it. And certainly the original Super Mario Kart and Gran Turismo. A car nut from an early age, Dominic was always drawn to racing games above all other genres. Now a seasoned driving simulation enthusiast, and former editor of Sim Racer magazine, Dominic has followed virtual reality developments with keen interest, as cockpit-based simulation is a perfect match for the technology. Conditions could hardly be more ideal, a scientist once said. Writing about simulators lead him to Road to VR, whose broad coverage of the industry revealed the bigger picture and limitless potential of the medium. Passionate about technology and a lifelong PC gamer, Dominic suffers from the ‘tweak for days’ PC gaming condition, where he plays the same section over and over at every possible combination of visual settings to find the right balance between fidelity and performance. Based within The Fens of Lincolnshire (it’s very flat), Dominic can sometimes be found marvelling at the real world’s ‘draw distance’, wishing virtual technologies would catch up.
  • psuedonymous

    What’s not entirely clear is whether Asynchronous Reporjection function in an always-on move like ATW (where EVERY frame gets reprojected with the latest IMU orientastion regardless of frame render time), or whether it is purely used for frame synthesis in case of late delivery.

    “Oculus, on the other hand, are Windows only” Well at the moment, so is the Vive. Valve have not confirmed that Async Reprojection to the Linux version, but the Linux version isn’t more than a ‘coming soon’ at the moment anyway.

  • DiGiCT Ltd

    Thanks Valve +1 ;-)

  • Raphael

    I tried this more than 3 weeks ago on one of the most demanding flight sims: DCS World 1.5 with Mig 21 aircraft. This combination is unplayable on my PC even with GTX 1070 because my vintage i5 2500k can’t handle it even at 4.8ghz. Oculus ASW makes it playable with CV1. Async reprojection on Vive does not. The performance improvement was minimal. Oculus ASW wins.

    • JustNiz

      No. Not relying on test results from beta versions and/or ugrading your CPU wins. With underpowered hardware, Oculus is also just hiding the problem not solving it.

      • Raphael

        Oculus is expanding the usability of CV1. Having tried ASW it renders an unplayable game playable. ASW artifacts are pretty much unnoticeable as long as people don’t go crazy with graphic settings too far beyond hardware spec. We all know that hardware performance needs to increase but opening up CV1 to lower spec systems is a very good thing.

        Test results from beta versions? Makes no difference whether it’s beta.
        Vive = unplayable for me with DCS + Mig 21.
        Playable with CV1. End result is all that matters.

        ASW also opens up CV1 to many more laptop users. Also a very good thing.

        A friend of mine with CV1 + GTX 970 is able to run higher graphic settings now on all his games and push up super-sampling.

        Have you actually tried it?

      • PrymeFactor

        Quit this fanboy rubbish.
        If with a Rift, a user is able to play a game that would have had unplayable frame rates otherwise, they’ve solved the problem.

      • Sam Illingworth

        Couldn’t play it, now can. Sounds like a solution to me. Perhaps you could share your definition of “solve”?

      • Dave

        +JustNiz How are they hiding the problem, there are lots of examples users have shared where ASW works. I don’t see how an improve experience can mean hiding the problem?

      • Wayne Gleeson

        Lol…fúcking tool..

      • d0x360

        I have zero issue running any rift game at the proper frame rate and I use full 360 degree tracking which uses more resources so I dunno what you are talking about.

        The oculus is compatible with steam and vive software too with zero issues.

    • d0x360

      Your first problem is an i5 due to lack of multi threading even if your running at 4.8 GHz

      Essentially they use as many threads as possible but with small tasks so a CPU that can multi thread has an advantage especially under dx12 or vulkan.

      The 1070 is a good GPU but not for VR due to the high frame rate and resolution requirements for each eye. AMD has the edge in VR right now

      • Raphael

        The GTX 1070 is fine for VR and we don’t even have the VR features running in most games yet. You’re talking utter pish. An i5 has multi-threading… it being multi-core and all. Just those cores are very slow and lacking compared to modern.

        Do u actually know anything about the 1070? Seems not. Nice plug for AMD but they still have the highest number of driver issues and problems with games especially VR.

        To start with the 1070 is slightly faster than the last generation Titan X. That’s without the VR specific features that will further boost performance on supporting games.

        A last gen Titan X is very good for VR and it depends on the game engine and game detail. But basically you’re talking a pile of cack.

        • d0x360

          An i5 DOES NOT have multi threading. Multiple cores isn’t multi threading and that statement alone is enough to end this conversation because you need to learn quite a bit more about hardware.

          Multi threading- 6 cores 12 threads (i7)
          No multi threading- 4 cores 4 threads (i5)

          As for the 1070…It’s not a top end card and neither is an i5 CPU.

          Get to reading.

  • ummm…

    does anybody know if I should not use the steamvr beta branch then? is the beta branch the current update plus more, or is it better to not use the beta branch anymore?

    • benz145

      Beat branch is newer but is buggier. Stay on the main branch if you want stability, go to beta if you want to try the latest stuff.

      • ummm…

        I’ve been on beta branch for some time. What sort of bugs ha e you noticed. I can’t tell the diff between bugs, and beta bugs.

  • Stoltenbergen

    Anyone know if/when it will be available for AMD cards?

  • Jerald Doerr

    I used this last night and it works grate so far… I can crank up the setting/over sampling! Games run ultra smooth and flicker is down… there’s even a night mode that turns down the brightness witch helps get rid of the bright reflections in the lances … it’s a button but I’d much more prefer a slider or someway to adjust the brightness contrast in your VR display.

  • Captain McKnight

    I tried AR when it went live on SteamVR beta but so far the it looks bad, even after multiple nvidia drivers reinstall.
    Is it normal to see objects and scenery ghosting with AR is on ? Like if you do a barrel roll with an aircraft, the horizon looks blurry and ghosting is clearly visible.

    I am just wondering if my system has an issue of if this is how it is supposed to look :(
    Any feedback appreciated folks ;)

  • guest101

    Reprojection techniques are mainly used to increase graphic quality while maintaining playable framerate. It doesn’t really accomplish their goal of lowering the minimum requirement. After all, reprojection requires GPU preemption which is only available on newer graphic cards.

    For example, even with the new reprojection techniques, Oculus’s minimum requirement is still GTX 960 or greater. As a comparison, with adaptive quality Valve was able to run their game on GTX 680.

    It is clear who actually accomplished their goal and who did not.

    • d0x360

      Except oculus is solving that issue in an update very soon. The issue also doesn’t exist at all when loading games through steam instead of oculus home.

    • Raphael

      U are quite correct about the multi-threading. That arse-tech link is from 03/2016… long before Oculus ASW. I’ve tried CV1 with ASW versus my Vive with async (also introduced late last year) and the Octopus wins. I’m a vive user but ASW lowers the hardware requirement.

      GTX 1070 isn’t a top end card? Who knew? So you believe that VR users should only buy GTX 1080 or high end ATI?

      Given that I can run Eve Valkyrie smoothly in VR on an ancient CPU… or that most VR games don’t have the graphics to push a GPU anywhere near capacity…

      So which ATI GPU do you use for VR? A single RX 480 doesn’t cut it…

      Go to reading? I’ve passed by it on the train but not sure if there’s anything of interest in that city.