Explanation
A technique that compensates for missed frames to maintain a fluid framerate. When the GPU cannot render fast enough, the system generates intermediate frames from previous ones, preserving the perception of smooth motion.
Real-world example
Creating an intermediate frame when the computer cannot keep up with 90 FPS.
Practical applications
- Performance compensation: maintaining perceived fluidity even when the GPU is struggling
- Motion sickness reduction: avoiding stuttering during framerate drops
- Spike tolerance: the application stays comfortable during complex scenes
- Quality/fluidity tradeoff: prioritizing user comfort
Types of reprojection
ASW (Asynchronous SpaceWarp)
- Generates intermediate frames from previous ones
- Compensates for head and object movement
- Meta/Oculus technology
Example: ASW 2.0 on Quest, reduces visual artifacts
Motion Smoothing / SteamVR Reprojection
- SteamVR equivalent for PCVR headsets
- Interpolates missing frames
- Can be enabled in SteamVR settings
Example: Valve Index with Motion Smoothing enabled
VR scenario
A highly detailed architectural visualization drops the framerate to 45 FPS in certain scenes. Thanks to ASW, the headset generates the missing frames to maintain a perceived 90 FPS. The user does not notice the issue.
Why it matters in professional VR
- Reprojection is an essential safety net for user comfort
- It allows developers to create more graphically ambitious applications
- It does not replace good optimization -- it should be used as a last resort