Valve has finally brought "Motion Smoothing" to AMD graphics cards in a Steam VR update this week. This feature aims to maintain a comfortable visual experience by estimating motion and animation based on the last two frames and inferring a new frame. The synthesized new frame helps applications maintain full frame rates while avoiding jitter. Motion Smoothing support for SteamVR initially landed on NVIDIA cards in November 2018.
In addition to other optimizations and bug fixes in the new version, SteamVR 1.4.14 has finally brought Motion Smoothing support to AMD RX and Vega graphics cards, but not to R9 and other older versions. Valve also stated that although newer versions of Radeon VII are technically supported, there is a bug in its graphics driver that prevents Motion Smoothing from working, and the company did not disclose when it will be fixed.
Motion Smoothing is similar to Oculus' ASW technology and helps maintain smooth and comfortable views inside VR headsets, even if there are occasional frame drops due to performance issues in PCs. When SteamVR detects that an application is unable to generate frame rates (i.e., starts dropping frames), Motion Smoothing kicks in and estimates motion and animation based on the last two frames to synthesize a new frame, maintaining full frame rates and avoiding jitter.
Motion Smoothing only supports Windows 10 and native OpenVR headsets such as Vive, Vive Pro, and others because headsets like Rift and WMR provide their own solutions to address frame drops.
Valve's new device, Index, offers higher resolution than the first-generation Vive and supports 90Hz, 120Hz, and 144Hz (experimental). Rendering at higher resolutions and frame rates requires better performance and is sensitive to slight performance decreases, making Motion Smoothing a critical feature for Index headset users.
SteamVR 1.4.14 has officially added support for Index, replacing the external drivers that developers previously needed. A series of new features, such as support for multiple frame rates provided by the headset and a new controller pairing UI (now including Index controllers and Vive trackers), will also be supported by the upcoming Index.
For the full release notes of SteamVR 1.4.14, please visit the Steam official website.