Performance benefit for elaborate rendering in Quest Pro

Quest Pro supports Eye Tracked Foveated Rendering, but how exactly is performance improved?

If you are unfamiliar with the term, Eye Tracked Sensational Viewing (ETFR) is a technique where Only the area of ​​the screen you are currently viewing is displayed in full resolution, so performance is released because the rest is less accurate. This additional performance can be used to improve the graphical resolution of applications, or to get a higher base resolution.

You don’t notice the low resolution in the periphery because the human eye itself can only see high resolution in the very center – the fovea. This is why you cannot read a page of text without moving your gaze. Believe it or not, the fovea area is only about 3 degrees wide.

ETFR has always been considered “Holy Grail” For VR, because if your GPU only has to display 3 degrees of field of view at full resolution, the performance advantage could be on the order of 20x. This would enable high-resolution screens or incredibly detailed graphics. But in reality, it requires achieving it perfect Latency-free eye tracking, absurdly high display refresh rate, and High quality rebuild algorithm So you don’t notice flickering and flickering.

Quest Pro is Meta’s first charging headset with eye tracking. The end-to-end latency of first-generation eye-tracking technology is 50ms, and the screen refresh rate is up to 90Hz. As such, the actual savings from its grainy rendering are nowhere near 20x.

Meta headphones supported fixed flowery rendering (FFR) – render file edges lens Less precisely – since Oculus Go six years ago. in accident This week, Meta provided developers with details about the exact performance benefits of eye tracking flowery rendering (ETFR) and compare it to FFR.

Both types of duplicate rendering are enabled by developers on a per-application basis (although obviously both types cannot be used at once). Developers are given three options for decreasing the ambient resolution: Level 1, Level 2, and Level 3. With ETFR Level 1, the surround is rendered with 4 x fewer pixels, while at Level 3 it’s mostly with 16x fewer pixels.

The exact performance benefit of the refined rendering also depends on the underlying resolution of the application. The higher the accuracy, the greater the savings.

In the Meta performance test application, they found with default accuracy that FFR saves between 26% and 36% of performance depending on the foveation level, while the new ETFR saves between 33% and 45%.

But at 1.5 times the default accuracy, the savings were even greater, with FFR offering 34% to 43% and ETFR offering 36% to 52%. That’s up to 2x a boost over not using foveation at all – but only a tiny benefit over FFR.

Of course, what really matters is what we don’t know yet: how marked Are all of these ETFR levels? And how does this compare to how clear FFR is? This is what to compare – not a certain level of FFR the same level of ETFR. This is something we will test in detail for our Quest Pro review.

In Quest 2 FFR Level 1 is not noticeable at all, but Level 3 is definitely. Since then Quest Pro Sharper lenses At both the center and the edges, FFR may be more pronounced than ever, making ETFR even more useful.

On PlayStation VR2, the purported performance advantage of an elaborate display is even greater. Sony claims FFR provides about 60%, while ETFR provides about 72%. This is probably due to the vastly different GPU architectures of consoles and PC GPUs compared to mobile GPUs, as well as the higher resolution. It could also be due to differences in eye tracking technology – Meta is internal while Sony Toby uses.

Eye tracking on both Quest Pro and PlayStation VR2 is optional for privacy reasons. But disabling it will obviously disable ETFR as well, so apps will have to fall back to FFR.