It’s a little-known fact that when Justin Timberlake told Mark Zuckerberg “A million dollars isn’t cool. You know what’s cool? A billion dollars,” he was talking about how expensive a good VR PC should be. Just jokes, there, some laugharoonies. But for plain ol’ millionaires whose VR experiences are bumpy, a little more help is coming. Valve have introduced a ‘Motion Smoothing’ beta feature to SteamVR, which should let slower PCs jack in with less trouble. Similar to Oculus’s Asynchronous Spacewarp tech and SteamVR’s own Asynchronous Reprojection, it works by sometimes estimating new frames rather than properly rendering them. Estimates aren’t as pretty, but are smoother than the alternative.
“When SteamVR sees that an application isn’t going to make framerate (i.e. start dropping frames), Motion Smoothing kicks in,” Valve explained in a blog post last week. “It looks at the last two delivered frames, estimates motion and animation, and extrapolates a new frame. Synthesising new frames keeps the current application at full framerate, advances motion forward, and avoids judder.”
Here comes the science part, concentrate.
“This means that the player is still experiencing full framerate (90 Hz for the Vive and Vive Pro), but the application only needs to render 1 out of every 2 frames, dramatically lowering the performance requirements. Even better, if synthesising a new frame for every frame delivered by the application still leads to performance issues, Motion Smoothing is designed to scale further down to synthesise 2 frames or even 3 frames for every 1 frame delivered.”
So the problem of cybergoggles wonking your eyes out with dodgy framerates is lessened. Valve say their new Motion Smoothing “improves upon” their old Asynchronous Reprojection (which was itself an improvement upon Interleaved Reprojection), though are a little vague about how and how much. Those synthesised frames still won’t look as good as the real deal, but smoothness is probably more important than fidelity when you’re jacking your face into cyberspace.
There are some limitations. Right now, the feature is only in beta and will only work with Nvidia graphics cards on Windows 10. And, Valve say, it “is not enabled when using Oculus Rift or Windows Mixed Reality headsets with SteamVR, because their underlying display drivers use different techniques when applications miss framerate.” A feature for Vive and other such goggs, then.