fpsVR data for P3Dv5 VR issues

[whitav8]

Here is a link to 3 JPG screenshots of P3Dv5 showing the application "fpsVR" results of various combinations of VR performance on my HP Reverb HMD. The various cominations have to do with whether any SteamVR reprojection was used to generate every other visual frame so that even though the HMD requires 90FPS, the system can apparently keep up with that even though only generating fully computed new frames at 45fps. I have tried using the following setups:
1) no reprojection and P3D frame limiter set at unlimited
2) motion vector reprojection at a fixed 45 fps and P3D frame limiter at unlimited
3) motion vector reprojection at a fixed 45 fps and P3D frame limiter at 45fps (which greatly reduced the left eye issues )
NOTE: other combos were tried but the left eye "tearing" when the head is rotated was too jarring

The SteamVR app "fpsVR" portrays key info during VR - frame rates with a sliding plot showing (for me) 11msec (90fps)lines and a 22msec (45fps) line which when exceed generates a visual stutter / double image. It also shows VRAM usage, RAM, and CPU core bar charts. My PC is a 9700K@5Ghz (Win 10 build 1903), 32gb RAM, RTX2070 (442.50), and the 90Hz HP Reverb which has 2160x2160 per eye resolution (I set SuperSampling at 100% ).

Hopefully the Devs can use these plots (I recommend getting fpsVR )to improve the left eye distortion issues (probably just a "sync" problem ) because on my PC, the imagery is very smooth (as long as I hold my head still ) compared to that on P3Dv4. In the benchmark situation that I use (scenery is ORBX at Monterrey KMRY ) with reasonably high scenery settings but medium to low shadows, reflections, low water, minimal traffic (see below). These settings produce about 100fps in nonVR and usually steady 45fps in VR.

First pic: https://1drv.ms/u/s!Ah-GN1pAHAEHkges_uld_GyRrAc7
P3D Frame=unlimited SteamVR Repro=off
Second pic :https://1drv.ms/u/s!Ah-GN1pAHAEHkgas_uld_GyRrAc7
P3D Frame=45fps SteamVR Repro=none
Third pic: https://1drv.ms/u/s!Ah-GN1pAHAEHkgWs_uld_GyRrAc7
P3D Frame=45fps SteamVR Repro=motionvector

This link points at the three images
https://1drv.ms/u/s!Ah-GN1pAHAEHkgis_ul ... 7?e=npECCb

The benchmark conditions and settings are given below:
_____________________________________________________________________________________________________
Conditions:
KMRY + Northern Cal from ORBX

Spring Day @1400 Fair Weather
A321 @10R

Graphics: FXAA=on, AA=4XMSAA. Ani=8x, TexRes=4096, Unlimited
LOD=Ultra,TessFac=High,Mesh=5m,TexRes=7cm, UseHighResTex,
Scene Comp=VeryDense, AutoGen=Medium,Veg+Bldg=Normal,DynamicVeg=on
Water Detail=Low, no Bath, no reflections
SpecEff=Medium
HDR=OFF, DynRef=off, LandLights=on
Shadow qual = Low, Shadow Draw Dist = Low, Casting+Rec = both for Internal and External
Cloud Draw Dist = 80, Density = Medium, Detail clouds, Vol Fog-on, Det Prec=on, Windshield effects=on
Traffic - Gen Av=10, Road Veh=10
VR=single pass
__________________________________________________________
Results
______________v4_____v5
nonVR HD_______96_____100
VR (2160x2160x2)__60____85-90 (No Reprojection and no Framelimit in P3D)

[Beau Hollis]

Thank you for this very detailed post. I believe we have idea of the cause of the left eye jitter and are working to resolve it. Our rendering is now threaded and happening concurrently with the update of the next frame. It looks like there is a potential for the a new set of poses to be captured after the left eye camera has processed and before the right causing the two cameras to be out of sync. In makes sense that certain combinations of settings and hardware would help mitigate the issue. For example, the render thread can be working while the frame limiter is waiting on the main thread, so limiting the frame rate increases your chance of the render work completing before the left eye update begins. Thanks again for posting these results.

[MPO910]

Good morning together!

I can completely agree with what the initiator of this topic wrote. I am using also a HP Reverb and the behaviour on my RIG is the same as described before.
I just wanted to post to let you know that this isn´t a single problem

I would also like to add the Info that I am seeing hardly no GPU utilization while using VR Mode. It directly drops to below 15% with turning on VR Mode. When turning the VR mode off, the GPU utilization starts rising again to above 80%.
I used the windows standard methods by viewing on the "performance TAB" via CTRL + ALT + DEL



There are several posts on AVSIM with identical issues. Some describe there issues with their HMD as jittery some as "input lag". The HMD wich are primarly used various from Oculus Rift S, Oculus Rift, HP Reverb, Samsung Odyssey and so far and so on.

But if I recall correctly, then there are also users complaining by using the "in sim VR HMD Oculus" mode. Do they really use reprojection similar processes?

I hope you guys can sort it out quickly.

My specs:
i7 8700k at 5.1GhZ
32 GB RAM 3600 MhZ Corsair Vengeance
RTX 2080ti inno3d
2x 1TB SSD NVME M2
P3D V5 latest build
Windows 10 Home lates build
All software and drivers (especially nvidia) fresh installed last monday. I completely whiped out everything and installed OS and P3D new

Thanks in advance and wish you all the best!
Regards Marcus

[whitav8]

Beau,
Looks like you are on the trail of the problem. Just one thing though is that it isn't just that the two images - left and right eye being perhaps one frame away from a matched set, but the left eye image can be maybe 5 to 10 degrees off of where it should be when turning the head at maybe 10 degrees per second - and secondly that just very small amounts of head movement (maybe less than 2 or 3 degrees) end up causing the above movement of 10 degrees or so - easily noticeable - as if the head measurement was being extrapolated incorrectly??

Good luck - when you find it please do a small patch hotfix so we all can try it on our various HMDs and various PCs. As I said, it looks like the improvement in VR is substantial as far as smoothness (fluidity - without stutters which really hurt VR).

Thanks

Dave W.

[YoYo]

Thank you for this very detailed post....

Its a VERY good news from this morning, I hope this issue will be solved soon as You can! :D

[Michael Thewissen]

Dear Beau Hollis,

on my system the left eye jitter becomes better or even goes away when I set fps to unlimited. Also, it is very bad with those aircraft that have glass cockpit. In the Maule and the R22 i.e., it is much less. Overall, there is much positive, distant terrain (mountains) are clearer and so on. If you need details of my setup (dxdiag.txt) please send me a PM.

Thank you & Good luck,
Michael

[vvince]

Hello,

I am also seeing the left eye flickering on the Oculus Rift S,
and wanted to add that reflection on water (sky and clouds) is shown in one eye only (do not remember which one, but can confirm later if needed), no reflection in the other eye.

Cheers
Vvince

Rift S, i9 9900K, GTX1080.

[Terry1718]

Hello,

I am experiencing similar issues regarding jittering as described above. With me its happening in both eyes. The underlying frame rate is very good however the jittering and out of sync L & R images make VR unusable for me.

In addition, when looking across a large body of water, cloud reflection's on the water surface are displayed in the left eye out to the horizon however in the right eye the reflections are only displayed within about 5 miles. This is also putting a strain on my eyes. I have the water slider set to ultra and clouds and user vehicle boxes ticked. My specs are;

Win10 v 1909 os build 18363.778
CPU Intel 8700K @5GHz
32Gb Ram
Nvidia 2080Ti FE driver version 445.87
Steam VR beta 1.11.9 on Valve Index, firmware up to date.

Hope this helps

[whitav8]

Beau,
A quick test for this issue of proper yaw VR eyepoint motion is to simply wiggle your head about 5 degrees left and right at 2 to 4 times per second and make sure that the aircraft cockpit windshield frame behaves properly - it should be stable to your eyes - just as it is when you simply swivel a large amount of degrees left or right. Right now it seems to "wobble" on my system. I will try various combinations of WMR-SteamVR reprojection and frame limits and report back. This actually might be a somewhat different problem than the left eye jitter issue.

Thanks

Dave W.

[YoYo]

Beau,
A quick test for this issue of proper yaw VR eyepoint motion is to simply wiggle your head about 5 degrees left and right at 2 to 4 times per second and make sure that the aircraft cockpit windshield frame behaves properly - it should be stable to your eyes - just as it is when you simply swivel a large amount of degrees left or right. Right now it seems to "wobble" on my system. I will try various combinations of WMR-SteamVR reprojection and frame limits and report back. This actually might be a somewhat different problem than the left eye jitter issue.

Thanks

Dave W.

Fingers crossed for this fix!

[jcrettew]

Another thing to add to the mix in case it is relevant. I can't use the mouse to click anything in the VR cockpit. The round dot cursor is there, but when I hover it over something I want to click, it acts like it is clicking elsewhere (haven't been able to figure out the pattern). Anyone else with the left eye problem experiencing this too?

[corbu1]

Hello,

I am experiencing similar issues regarding jittering as described above. With me its happening in both eyes. The underlying frame rate is very good however the jittering and out of sync L & R images make VR unusable for me.

In addition, when looking across a large body of water, cloud reflection's on the water surface are displayed in the left eye out to the horizon however in the right eye the reflections are only displayed within about 5 miles. This is also putting a strain on my eyes. I have the water slider set to ultra and clouds and user vehicle boxes ticked. My specs are;

Win10 v 1909 os build 18363.778
CPU Intel 8700K @5GHz
32Gb Ram
Nvidia 2080Ti FE driver version 445.87
Steam VR beta 1.11.9 on Valve Index, firmware up to date.

Hope this helps

I can confirm the issue with clouds reflections on large water bodies on my Vive Pro. It‘s painful on the eyes, so I had to untick cloud reflections in the watersettings

Besides that, general VR performance is great compared to v4. Thank you LM!

[Beau Hollis]

Hello all,

I have some good news to report. We tracked down the issue and have a fix for it. Thankfully, our virtual reality module is built as an add-on using our SDK, so we can create a small add-on to replace it without modifying any files in the install directory. Our plan is to package this fix up as an add-on and provide a link to it here on the forums, so that you will have the opportunity to test it out and provide feedback. We will post back with more details when the add-on is available for download.

Thanks again for all the feedback.

[BigG]

Fantastic news Beau! I'm really anxious to try out the VR fix. Really appreciate the effort to get this resolved quickly...g

[YoYo]

Hello all,
.....

Great! I can test it as beta tester also ;D.

Steam VR WMR, VR: HP Reverb v2.