Steam VR Introduces 'Motion Smoothing' So Low-End PCs Can Run Games More Smoothly (engadget.com)

Steam VR is introducing a new feature called "Motion Smoothing" that will give PCs with low-end hardware the power to deliver VR experiences more smoothly. "It functions like Motion Smoothing for TV and Asynchronous Spacewarp for Oculus devices, which are frame-rate smoothing techniques that generate synthetic frames between two real ones in order to avoid a stuttery experience," notes Engadget. From the report: When Steam VR determines that an experience is lagging or dropping frames, Motion Smoothing automatically kicks in. It drops an app's framerate from 90FPS to 45FPS and generates a synthetic frame for every real one to mimic real 90FPS. If things get especially bad, it can generate two to three frames for every real one instead. Steam explains that the feature "dramatically [lowers] the performance requirements," allowing PCs with lower end hardware to "produce smooth frames." Take note, however, that the feature will not work with the Oculus Rift or with Windows Mixed Reality headsets. You can only take advantage of it if you have an HTC Vive or a Vive Pro, and if you're running Windows 10 -- all you need to do is right-click on Steam VR and select beta under Tools in Library.

Comments

"Motion Sickness" replaced with "Laggy Responses"

[Anonymous Coward]

If you're trying to run VR on low-end HW, you deserve the headache you fuckwit.

It had better NOT function like that

[wonkey_monkey]

It functions like Motion Smoothing for TV

I hope not, because that will introduce additional lag. TV smoothing needs to know what the next frame is before it can smoothly transition to it. So sure, do it that way if you want make people even more motion sick...

Hopefully what it will do instead is generate the first frame and immediately display it, and instead of rendering the next frame completely, it'll warp the first frame to approximate the geometry of the skipped frame. Pretty sure this was touted as a thing a while ago though.

Re:It had better NOT function like that

[Guspaz]

VR motion smoothing and asynchronous spacewarp don't really work like that. What they do is they take the last known frame produced by the graphics card and then warp it to match the user's current position in space. This actually reduces latency because it means the user's view is being updated by their position more often than if it was just using the less frequent frames from the graphics card. They aren't interpolating between two frames (well, maybe Valve's new thing does that, Oculus asynchronous spacewarp doesn't), they're warping the image to reflect more recent positional data.

In fact, one strategy to reduce latency even when the GPU is putting out the full HMD framerate is to sample the positional data after the frame is rendered but right before the frame is sent to the HMD and use asynchronous spacewarp to update the rendered frame. This means the position displayed to the user is more recent than when the game engine sampled the position in its gameplay loop (and before anything was rendered), which can potentially remove most of the rendering latency.

Re:It had better NOT function like that

[Immerman]

Quite so. Obviously it does create artifacts - warping can't reveal whatever was just exposed beyond that column for example, so the edges of things may have a tendency to shimmer with interpolated "noise" when you're in motion. Whether that's noticeable or not? No idea.

There's also going to be a performance penalty - unless using dedicated hardware for that part. Warping an HD image may be computationally cheaper than rendering it in the first place, but every ns spent doing so is a ns not available for rendering better graphics.

Probably both prices well worth paying though, if it lets your eyes see something much closer to what your inner ears are saying they should.

Re:It had better NOT function like that

[Anonymous Coward]

Everyone in this thread is wrong. Since nobody can be bothered to read the actual Valve announcement:

"The way we are applying Motion Smoothing in SteamVR is a bit different. When SteamVR sees that an application isn’t going to make framerate (i.e. start dropping frames), Motion Smoothing kicks in. It looks at the last two delivered frames, estimates motion and animation, and extrapolates a new frame. Synthesizing new frames keeps the current application at full framerate, advances motion forward, and avoids judder."

Lag

[Anonymous Coward]

This is a nice feature, but what about increased lag since multiple frames are required to render a missing frame for motion compensation?

Only on HTC Vive

[PhrostyMcByte]

Because Oculus has had the same thing -- called asynchronous time-warp and then a new version asynchronous space-warp -- for two or three years.

Welcome to the future!

In seriousness --- even high-end PCs can often not maintain a perfect 90fps in all scenes of many games. This is useful for them too, because changes in framerate are very easy to see and can be disorienting. This allows full motion, rendering rotation etc. while it lerps between frames. It works great.

Re:"Motion Sickness" replaced with "Laggy Response

[Anonymous Coward]

If you're trying to run VR, you deserve the headache you fuckwit.

FTFY

Ugh.

[antdude]

No, I hate that feature. Please make it an option.

Re: Ugh.

[Anonymous Coward]

"right-click on Steam VR and select beta under Tools in Library"

Reading TFS. Ugh, right?

Re:TVs have been doing it for decades

[Carewolf]

Bye bye contrast and sharpness, hello blurriness.

The new methods doesn't look blurry. They look sharp and smooth, but super weird and motion sickness inducing. And everybody moves like some kind of alien creature.

Lowers performance requirements?

[ayesnymous]

Now you have software that needs to detect dropped frames and generate fake frames. Then it needs to display the same number of frames as before, regardless of whether they're real or fake frames. So it's doing the same thing as before, but with the addition of needing to detect dropped frames and generate fake frames. And there's less of a performance requirement for all that?