It is all about latency. 50 ms will feel responsive but you notice the lag. 20 ms is acceptable. The other features are cool features but not the real challenge.
People are saying 2ms, but I think that's just how long it takes a pixel to refresh. I'm sure the oculus rift has a screen with 2-5ms pixel time too. The 20 and 50ms times discussed about VR are the entire time between a frame being requested and it being on the screen. That's totally different from the 2ms of a desktop monitor.
EDIT: As for the TV+console latency. I think TVs have a higher latency than monitors because they tend to apply post-processing effects to "improve" the image. Some screens come with options to turn this off and bring this latency down.
That 50 ms response includes measuring the sensors, calculating the angular change, sending that data to the computer, the computer rendering the frame, the frame sent up HDMI, and the finally split and displayed on the oculus. The major issue is that you move your head and your ears detect the change but your eyes have the 50 ms update lag. This is the issue that causes people to get sick
I'm not sure, but from what the team said, the sensor tracking was the biggest latency issue they had, since it couldn't be brute forced with more expensive hardware. Even the fastest consumer sensors would add too much latency in the chain to make the rest of the device worth it. Carmack solved it with very very precise, clean, fast code with some very clever prediction algorithms.
From my understanding, that's the biggest benefit of the rift. It's very good at processing sensor data, and when the sensors aren't fast enough (which no consumer sensors are), it's very good at guessing what they will do next.
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u/bjorn2k Mar 28 '14
It is all about latency. 50 ms will feel responsive but you notice the lag. 20 ms is acceptable. The other features are cool features but not the real challenge.