PSVR2 - now works with Eye Tracking and Quad Views!

[RealDCSpilot]

For me, and this changed my mind to never want to use a wireless VR hmd again, their biggest caveat besides compression is latency. For sims with HOTAS or steering wheels, latency has a huge impact. I was using VR streaming with a standalone HMD for two years and got used to it, but the moment i tried the PSVR2 with cable in a helicopter was a real eye opener. All of a sudden i had direct control over the aircraft, rudder, cyclic and collective felt so much different than before. I'll never go back.

[Qcumber]

1 hour ago, RealDCSpilot said:

For me, and this changed my mind to never want to use a wireless VR hmd again, their biggest caveat besides compression is latency. For sims with HOTAS or steering wheels, latency has a huge impact. I was using VR streaming with a standalone HMD for two years and got used to it, but the moment i tried the PSVR2 with cable in a helicopter was a real eye opener. All of a sudden i had direct control over the aircraft, rudder, cyclic and collective felt so much different than before. I'll never go back.

I only see latency wireless with VD. With oculus link cable there is no noticeable latency. It's the same as when using my Rift S. I still wish that the QP had DP though. 

[RealDCSpilot]

17 hours ago, Qcumber said:

I only see latency wireless with VD. With oculus link cable there is no noticeable latency.

Sorry man, but there is no tech magic possible to reduce the latency of the odyssey a rendered frame has to take through the route of streaming over wifi or usb cable. With a direct Displayport connection it will take a rendered frame only 1-3 ms to reach the display panels, while going through all the hoops and loops of processing needed for streaming over USB or Wifi you'll always end up with 40 - 80 ms. It's all the encoding and decoding, hacking everything into little transferable packets vs. just flushing it through a big pipe.
Even with "Oculus Link" you'll end up with 20 to 40 times the latency the sim is actually meant to be played.

You will "see" it, once you have the chance to compare it directly. I had two years of built up muscle memory with a standalone headset and was a bit shocked about the difference. When i changed my setup, i also did a DCS session with standalone HMD before and after the change to PSVR2 (which was roughly within 20 minutes).

You can go into details here: https://pimax.com/de/blogs/highlights/technical-comparison-displayport-direct-connection-vs-quest-3-streaming-solutions-for-pcvr

Edited yesterday at 05:14 AM by RealDCSpilot

[Qcumber]

6 minutes ago, RealDCSpilot said:

Sorry man, but there is no tech magic possible to reduce the latency of the odyssey a rendered frame has to take through the route of streaming over wifi or usb cable. With a direct Displayport connection it will take only 1-3 ms while going through all the hoops and loops of processing needed for streaming over USB or Wifi you'll always end up with 40 - 80 ms. It's all the encoding and decoding, hacking everything into little transferable packets vs. just flushing it through a big pipe.
You can go into details here: https://pimax.com/de/blogs/highlights/technical-comparison-displayport-direct-connection-vs-quest-3-streaming-solutions-for-pcvr

That's why I said "noticable". I was comparing my experience with the Rift S and Quest Pro. With VD there is a lag when moving your head quickly. I don't see this with quest link cable. 

[RealDCSpilot]

Ah i see, that's another type of latency on top. Called motion-to-photon. Your headset has to collect and process your movements, send it to your PC - process and apply it to the game - render it - compress it - send it back over Wifi or USB - decompress it and render it on your display panels again.

[Cytarabine]

19 hours ago, RealDCSpilot said:

Sorry man, but there is no tech magic possible to reduce the latency of the odyssey a rendered frame has to take through the route of streaming over wifi or usb cable. With a direct Displayport connection it will take a rendered frame only 1-3 ms to reach the display panels, while going through all the hoops and loops of processing needed for streaming over USB or Wifi you'll always end up with 40 - 80 ms. It's all the encoding and decoding, hacking everything into little transferable packets vs. just flushing it through a big pipe.
Even with "Oculus Link" you'll end up with 20 to 40 times the latency the sim is actually meant to be played.

You will "see" it, once you have the chance to compare it directly. I had two years of built up muscle memory with a standalone headset and was a bit shocked about the difference. When i changed my setup, i also did a DCS session with standalone HMD before and after the change to PSVR2 (which was roughly within 20 minutes).

You can go into details here: https://pimax.com/de/blogs/highlights/technical-comparison-displayport-direct-connection-vs-quest-3-streaming-solutions-for-pcvr

The magic comes not from any technical wizardry but from how our brains perceive latency. When repeatedly exposed to latency of up to around 150msec our brain adapts and we perceive events such as our motor input on the controls and the visual feedback in the headset as being simultaneous. 

That however does not make the events simultaneous in reality and means that for things where a delay could be significant (like say oblique gunnery in BFM) the effect is still there even though we don’t perceive it. 

So when someone says they can’t feel any latency with a standalone headset they are entirely correct, they can’t feel it. That doesn’t mean however it isn’t there. 

[Qcumber]

5 hours ago, Cytarabine said:

The magic comes not from any technical wizardry but from how our brains perceive latency. When repeatedly exposed to latency of up to around 150msec our brain adapts and we perceive events such as our motor input on the controls and the visual feedback in the headset as being simultaneous. 

That however does not make the events simultaneous in reality and means that for things where a delay could be significant (like say oblique gunnery in BFM) the effect is still there even though we don’t perceive it. 

So when someone says they can’t feel any latency with a standalone headset they are entirely correct, they can’t feel it. That doesn’t mean however it isn’t there. 

At a steady 72fps, VD has a latency of about 35-40 ms which includes game, encoding, networking and deciding latencies. I presume that with DP the only major latency is game latency? So with a maximum game latency of 13.8 ms (to maintain 72 fps) the overall DP latency would be about 20 ms. Am I working this out correctly?

I don't know what the latencies are through oculus link cable, but the bitrate is 960 mbps h264 vs 150 mbps HEVC10 with VD. So I presume the latency would be a bit less with oculus link!?

Do these latencies affect eye tracking? Is the tracking better through DP vs a link with compression? 

[RealDCSpilot]

7 hours ago, Cytarabine said:

So when someone says they can’t feel any latency with a standalone headset they are entirely correct, they can’t feel it. That doesn’t mean however it isn’t there.

Yeah sure, it tricks your brain. I got totally used to it with my standalone HMD. But to describe the effect better - i would call it the "old man" filter. Everything reaction time based get's "stretched and smoothed out" in time. Something like this. Stuff becomes more unresponsive. It becomes extremely obvious in helicopter takeoffs, like with the AH64. I have a full HOTAS in a seat, so i have to work with all arms and feet to coordinate a clean takeoff with cyclic, collective and pedals. You have to do a lot of work with micro corrections and my fist takeoff with the PSVR2 was quite an experience after years with of streaming VR.

@Qcumber Yeah, you have to take your whole system latency into account, add HOTAS device input latency and so on. In the end you'll have that huge latency chunk of VR streaming in the middle of that data pipeline, which is a massive bottleneck compared to everything else. Based on some old numbers i remember it's ~15ms if you are running with DP and controllers over USB. With streaming you end up with 60 ms and more (VD numbers do only show what is relevant to the VR streaming part), don't forget that DCS is CPU bound and you are putting extra work with streaming on it. More realistic would be 80 to 100 ms even with highend hardware.

Edited 3 hours ago by RealDCSpilot