Hi, I've recently installed Windows 8.1 Pro as second operating system.I'm observing that Extended Desktop mode is no working correctly ?Somehow this issue is not picked up by anybody?Here are just 3 threads I fould that mention this issue:https://forums.oculus.com/viewtopic.php?f=34&t=17545https://forums.oculus.com/viewtopic.php?f=34&t=16829https://forums.oculus.com/viewtopic.php?f=34&t=15972In short:- When in Extended Desktop mode:- Oculus Display is detected differently on Windows 8.1 and Windows 7- In "Landscape" mode there is no Judder ( but everything is rotated by 270 degree, so it looks flipped upside-down ).- In "Landscape (flipped)" mode display is properly rotated by 90 degree, but there is terrible judder.My observations after reading other threads:- Windows 8.1 has no Aero mode to disable, so it won't fix it- Nvidia drivers are no longer supporting display rotation on GPU (since WinXP) which means desktop compositing system does it on CPU, and then it probably forces sync of all displays to common refresh rate which is 60Hz - Judder appears.- Windows 8.1 does display rotation in reversed direction in comparison to Windows 7.WA proposed by others that are not taken into notice:- Decrease resolution of primary monitor and force it to 75Hz -> Not every display can be bumped to 75Hz- Set Oculus DK as primary monitor -> I don't believe any customer will integrate into his settings so much, it's to complicated for end users, then they need to switch it forth and back, Oculus should just work for them- Disable other displays except Oculus -> the same as aboveMy WA proposition for now (will need to implement it):- Set in Extended Desktop mode Oculus to Landscape (everything is "upside-down" but we don't have judder).- Detect in game Windows 8.1 (somehow??)- When performing distortion rendering take into notice rotation by 270 degrees and flip everything with proper matrix- As a result this should remove issue for nowReproduced on:- Windows 8.1 Pro- Oculus DK2- Extended Desktop mode- NO legacy support for DK1- Rift Saver ON- OpenGL, NON-SDK cutom rendering (works correctly on Windows 7).- VSync is ON.Cannot observe the issue in OculusRoomTiny 0.4.4 (works correctly in both SDK, and Custom rendering mode).It renders in DX11 so maybe difference in swap-chain is the answer?OculusWorldDemo (forced to GL) is not detecting properly DisplayID for HMD which results in creating window on Monitor instead of Oculus so I cannot check judder there.Question to dev team:- Can you confirm judder-flip issue on Windows 8.1 and Oculus OpenGL Extended Desktop mode ?

I've done more research and it looks like WA proposed by me is not working (which is REALLY weird).Please look at this 3 situations:1) Oculus is in "Landscape" mode, so that everything renders rotated by 270 degrees and looks "flipped", game renders exactly the same as in Windows 7 where display is properly positioned. There is NO judder.2) As I'm rendering using OpenGL I'm using such modification of scale and offset on Windows 7 to take into notice flipped Y axis in Framebuffer: float2 scale = float2(settings[i].UVScaleOffset[0].x, settings[i].UVScaleOffset[0].y); float2 offset = float2(settings[i].UVScaleOffset[1].x, settings[i].UVScaleOffset[1].y); // OpenGL invert framebuffer Y axis scale.y = -scale.y; offset.y = 1.0f - offset.y; eyeToSourceUVScale.set(scale); eyeToSourceUVOffset.set(offset);So it seems logic, that to fix Windows 8.1 "flipped" rendering I just need to do this: float2 scale = float2(settings[i].UVScaleOffset[0].x, settings[i].UVScaleOffset[0].y); float2 offset = float2(settings[i].UVScaleOffset[1].x, settings[i].UVScaleOffset[1].y); // OpenGL in Windows 8.1 WA - Flip in both Y and X axes to emulate rotation by 270 degrees //scale.x = -scale.x; eyeToSourceUVScale.set(scale); eyeToSourceUVOffset.set(offset);3) Above code looks ok, but maybe it is not taking into notice time-warp matrices? So let's just modify final position in VS instead of scale and offset:#version 110attribute vec2 inPosition;attribute vec2 inTexCoord0;attribute vec2 inTexCoord1;attribute vec2 inTexCoord2;attribute float inVignette;attribute float inTimeWarp;varying vec4 Position;varying float Vignette;varying vec2 TexCoord0;varying vec2 TexCoord1;varying vec2 TexCoord2;uniform vec2 EyeToSourceUVScale;uniform vec2 EyeToSourceUVOffset;uniform mat4 EyeRotationStart;uniform mat4 EyeRotationEnd;vec2 TimewarpTexCoord(vec2 TexCoord, mat4 rotMat){// Vertex inputs are in TanEyeAngle space for the R,G,B channels (i.e. after chromatic// aberration and distortion). These are now "real world" vectors in direction (x,y,1)// relative to the eye of the HMD. Apply the 3x3 timewarp rotation to these vectors.vec3 transformed = vec3( vec4(rotMat * vec4(TexCoord.xy, 1.0, 1.0) ).xyz);// Project them back onto the Z=1 plane of the rendered images.vec2 flattened = (transformed.xy / transformed.z);// Scale them into ([0,0.5],[0,1]) or ([0.5,0],[0,1]) UV lookup space (depending on eye)return (EyeToSourceUVScale * flattened + EyeToSourceUVOffset);}void main(){ mat4 lerpedEyeRot = ((1.0 - inTimeWarp) * EyeRotationStart) + (inTimeWarp * EyeRotationEnd);Position = vec4(inPosition.xy, 0.5, 1.0);Vignette = inVignette; TexCoord0 = TimewarpTexCoord(inTexCoord0, lerpedEyeRot);TexCoord1 = TimewarpTexCoord(inTexCoord1, lerpedEyeRot);TexCoord2 = TimewarpTexCoord(inTexCoord2, lerpedEyeRot);// Windows 8.1 flip fix WAPosition.x *= -1.0;Position.y *= -1.0;// To be compatible with GLSL 1.10gl_Position = Position;}Now taking into notice original situation and 2 proposed fixes lets see what really happens:1) From logs it looks like Oculus is in fact rendering in 60Hz ! ( propably forced to by Windows 8.1 compositing system?).As it is set to 75Hz we see in logs that time-warp is struggling with 60Hz VSync:Frame time = 9.04 ms sync time = 6.8310 msFrame time = 7.61 ms sync time = 5.5600 msFrame time = 16.68 ms sync time = 14.6650 msFrame time = 16.63 ms sync time = 14.5800 msFrame time = 16.68 ms sync time = 14.6500 msFrame time = 8.98 ms sync time = 6.9420 msFrame time = 7.63 ms sync time = 5.7750 msFrame time = 16.66 ms sync time = 14.7530 msFrame time = 16.66 ms sync time = 14.7670 msFrame time = 16.65 ms sync time = 14.7660 msFrame time = 16.64 ms sync time = 14.7670 msFrame time = 5.70 ms sync time = 3.8060 msFrame time = 10.98 ms sync time = 9.1970 msFrame time = 16.63 ms sync time = 14.7320 msFrame time = 16.69 ms sync time = 14.7170 msFrame time = 16.64 ms sync time = 14.7500 msFrame time = 5.62 ms sync time = 3.7520 msFrame time = 10.99 ms sync time = 9.1470 msFrame time = 16.67 ms sync time = 14.8370 msFrame time = 16.65 ms sync time = 14.7420 msFrame time = 16.64 ms sync time = 14.7310 msBUT THERE IS NO JUDDER ????Q1: How it is possible? 2) Now lets look at results of runig app with WA in flipped scale :Frame time = 2.01 ms sync time = 1.3120 msFrame time = 14.50 ms sync time = 13.8720 msFrame time = 16.63 ms sync time = 16.0240 msFrame time = 16.56 ms sync time = 15.9930 msFrame time = 16.72 ms sync time = 16.1580 msFrame time = 2.50 ms sync time = 1.9210 msFrame time = 14.18 ms sync time = 13.6320 msFrame time = 16.68 ms sync time = 16.1020 msFrame time = 16.75 ms sync time = 16.1520 msFrame time = 16.53 ms sync time = 15.9450 msFrame time = 2.40 ms sync time = 1.7920 msFrame time = 14.27 ms sync time = 13.7370 msFrame time = 16.68 ms sync time = 16.1020 msFrame time = 16.59 ms sync time = 15.9720 msFrame time = 16.61 ms sync time = 16.0190 msNow image renders correctly.We are still forced to 60Hz, BUT NOW THRERE IS SIGNIFICANT JUDDER ???How it is possible that just switching scaling x and y sign introduces judder ?One can say that it is because Time-Warp matrices are not taken into notice then.3) Ok, so let's just flip X and Y sign of vertices position at the end of VS:Frame time = 3.17 ms sync time = 0.0010 msFrame time = 13.45 ms sync time = 0.0020 msFrame time = 17.00 ms sync time = 0.0060 msFrame time = 16.36 ms sync time = 0.0070 msFrame time = 16.52 ms sync time = 0.0060 msFrame time = 3.19 ms sync time = 0.0030 msFrame time = 13.65 ms sync time = 0.0040 msFrame time = 16.63 ms sync time = 0.0020 msFrame time = 16.67 ms sync time = 0.0030 msFrame time = 16.66 ms sync time = 0.0020 msFrame time = 2.98 ms sync time = 0.0020 msFrame time = 13.83 ms sync time = 0.0040 msFrame time = 16.47 ms sync time = 0.0020 msFrame time = 16.62 ms sync time = 0.0030 msFrame time = 16.66 ms sync time = 0.0020 ms(PS: don't look at sync time here, counte was changed and is not reflecting it anymore, look at frame time)The same result! Correct rendering, Oculus fighting with 60Hz VSync and HORRIBLE JUDDER even though I've just changed vertices final orientation on the screen.TL;DR:- In Extended Desktop mode Oculus looks to be rendering in 60Hz (even though set to 75Hz) but there is NO judder.WHY ?- How to FORCE Oculus to run in 75Hz in Windows 8.1 ? (there is no Aero to disable there )- Why changing sign of vertex x and y values introduces Judder ?? How it is even possible ? Oculus Dev Team, please let's solve this together.

As I've mentioned earlier, I wasn't taking into notice WA's that are not acceptable from release application point of view:WA proposed by others that are not taken into notice:- Decrease resolution of primary monitor and force it to 75Hz -> Not every display can be bumped to 75Hz- Set Oculus DK as primary monitor -> I don't believe any customer will integrate into his settings so much, it's to complicated for end users, then they need to switch it forth and back, Oculus should just work for them- Disable other displays except Oculus -> the same as aboveI've finally decided to try them as it looks like there is completly no interest in this issue from Oculus support team.So here is solution that works, but it is dirty WA that is unacceptable for customer product release:- Set Oculus in Extended Desktop mode to Landscape (everything is "upside-down" but we don't have judder).- Now set Oculus as primary display. - Detect in game that it is running on Windows 8.1- When performing distortion rendering take into notice rotation by 270 degrees and flip everything with proper matrix, or even simpler, by adding this two lines in your distorion shader:// Windows 8.1 flip fix WAPosition.x *= -1.0;Position.y *= -1.0;Your game will render correctly in 75Hz without judder now.But as you can guess, now all your icons and start menu are on Oculus display, and all new opened windows will appear there as well. And as if there were not enough of bad things already, all that will be flipped upside-down. I hope Oculus team will be willing to fix that quickly, or add proper OpenGL support to direct mode.

Wow. I have the exact same problem that you are describing here. I'm not a programmer and this workaround seems pretty complex but I might be willing to give it a try. Is there any way you could provide step by step instructions on how to get this working? I'm not quite clear on what you mean by getting the game to detect that it is running in 8.1 or how to access the distortion rendering and where you would paste the code to flip the image. Thanks.

This WA steps are for developers.- Game needs to detect that it is currently running on Windows 8.1 to render flipped image only then. If it is running on Windows 7 it should render normally. - Only game developer can modify game code or shaders to apply this WA lines.Because of above, end users like you are unable to apply this WA. And this is why Oculus team should look into this (probably cooperate with Windows team as well if it is possible).

That's a shame. I've been trying to get my oculus working with Elite Dangerous and was really hoping for a fix. It looks great when you set it to landscape but everything is upside down. landscaped flipped makes the orientation correct but induces judder. I'm really hoping that someone comes up with a fix or workaround soon. Thanks for all your work in figuring this stuff out. Hopefully the oculus team will work on patching it to take this into account.

MrKaktus

Explorer

11 years ago

Win8.1 judder in landscape(flipped) [working WA proposed]

Hi, I've recently installed Windows 8.1 Pro as second operating system.
I'm observing that Extended Desktop mode is no working correctly ?
Somehow this issue is not picked up by anybody?

Here are just 3 threads I fould that mention this issue:
https://forums.oculus.com/viewtopic.php?f=34&t=17545
https://forums.oculus.com/viewtopic.php?f=34&t=16829
https://forums.oculus.com/viewtopic.php?f=34&t=15972

In short:
- When in Extended Desktop mode:
- Oculus Display is detected differently on Windows 8.1 and Windows 7
- In "Landscape" mode there is no Judder ( but everything is rotated by 270 degree, so it looks flipped upside-down ).
- In "Landscape (flipped)" mode display is properly rotated by 90 degree, but there is terrible judder.

My observations after reading other threads:
- Windows 8.1 has no Aero mode to disable, so it won't fix it
- Nvidia drivers are no longer supporting display rotation on GPU (since WinXP) which means desktop compositing system does it on CPU, and then it probably forces sync of all displays to common refresh rate which is 60Hz - Judder appears.
- Windows 8.1 does display rotation in reversed direction in comparison to Windows 7.

WA proposed by others that are not taken into notice:
- Decrease resolution of primary monitor and force it to 75Hz -> Not every display can be bumped to 75Hz
- Set Oculus DK as primary monitor -> I don't believe any customer will integrate into his settings so much, it's to complicated for end users, then they need to switch it forth and back, Oculus should just work for them
- Disable other displays except Oculus -> the same as above

My WA proposition for now (will need to implement it):
- Set in Extended Desktop mode Oculus to Landscape (everything is "upside-down" but we don't have judder).
- Detect in game Windows 8.1 (somehow??)
- When performing distortion rendering take into notice rotation by 270 degrees and flip everything with proper matrix
- As a result this should remove issue for now

Reproduced on:
- Windows 8.1 Pro
- Oculus DK2
- Extended Desktop mode
- NO legacy support for DK1
- Rift Saver ON
- OpenGL, NON-SDK cutom rendering (works correctly on Windows 7).
- VSync is ON.

Cannot observe the issue in OculusRoomTiny 0.4.4 (works correctly in both SDK, and Custom rendering mode).
It renders in DX11 so maybe difference in swap-chain is the answer?
OculusWorldDemo (forced to GL) is not detecting properly DisplayID for HMD which results in creating window on Monitor instead of Oculus so I cannot check judder there.

Question to dev team:
- Can you confirm judder-flip issue on Windows 8.1 and Oculus OpenGL Extended Desktop mode ?

18 Replies

Anonymous
11 years ago
Any new movement on this issue? It seems like most (if not all) Win8.1 users are having this exact problem. :cry:
kwild
Explorer
11 years ago
Well,that BIG problem was discovered months ago but we got no words from developers!
The problem seems the most important cause of "judderin" in Win 8.1 but seems almost ignored.
That's very embarassing!!!
dan_keating
Honored Guest
11 years ago
Has anyone gotten to the bottom of this?

I didn't believe it until I tried it. My main issue appears to be judder in Elite Dangerous and I'm not knocking the team that developed the game here. There are some known areas where judder really stands out. Surprisingly, running the desktop as 'portrait flipped' (AMD ATI Catalyst) seems to vastly reduce judder and really increase fluidity. Flip back to 'portrait' and it comes back. Win 8.1 desktop settings don't appear to match Catalyst for orientation for whatever reason.

The difference between the two orientations is HUGE !!!
Slaventsiy
Honored Guest
11 years ago
I'm experiencing the judder on Surface Pro 3 in a very simple project with flipped landscape and there is no judder with just landscape even though the framerate in both cases stays the same around 50fps.
I don't understand where should I apply the fix with flipping the axis as mrkaktus mentioned, am I supposed to rewrite the shader for that?
Lhun
Explorer
11 years ago
If your monitor can do 75HZ, and you have to run in extended (for something like elite), disable timewarp if the app supports it. YMMV, timewarp on nvidia cards should give you less judder.
(landscape, flipped)
Secondly, make sure vsync is on in the game (and that you get better then 80fps with vsync off).

that's it, and your judder (should) go away. (it does for me on an R9 290)

New Retro Arcade is a great way to test this - they have a framerate counter which you can access with L bumper.
Direct to rift is ALWAYS better.
Slaventsiy
Honored Guest
11 years ago
"Lhun" wrote:
If your monitor can do 75HZ, and you have to run in extended (for something like elite), disable timewarp if the app supports it. YMMV, timewarp on nvidia cards should give you less judder.
(landscape, flipped)
Secondly, make sure vsync is on in the game (and that you get better then 80fps with vsync off).

that's it, and your judder (should) go away. (it does for me on an R9 290)

New Retro Arcade is a great way to test this - they have a framerate counter which you can access with L bumper.
Direct to rift is ALWAYS better.

I have to run everything in extended, since even OvrConfigTool crashes when I try to run demo in Direct HMD Access mode. The monitor doesn't support more than 60Hz, Vsync is set to "Every V blank". Disabling timewarp didn't help, only dropped the FPS down. But as I said, if the Oculus is set to landscape — the project runs very smooth as opposed to landscape flipped.
Lhun
Explorer
11 years ago
Humm.

Before I had a monitor that could do 75hz, I actually reconfigured using Custom Resolution Utility to a resolution my screen plainly didn't support. I had my monitor in that resolution ONLY when windows flipped to extended desktop mode. And, because monitors contain protection for this (for the most part), it would simply say "out of range". I set it up in such a way that turning off the rift would set it back.

Here's how:

With your primary monitor attached, set the proper resolution for it in single display mode. Have your rift off (via the power button).

Turn your rift on. Windows should now see a second display, as extended. Set the rift up to landscape(flipped) at 75hz and everything correctly. It should be to the right and "Desktop 2". Load up Virtual Desktop so you can see your primary monitor on the rift. You will notice the capture rate in virtual desktop goes to hell (1-6fps) when the primary display is 60hz.

from virtual desktop: go back to your monitor in display properties.
Set it to the 75hz unsupported resolution, and click apply. Your monitor will click off and say "out of range". That's okay. Windows is still rendering the display.

Notice how the capture rate in virtual desktop is now 45-75fps? This is indicative of the problem. Launch your games from virtual desktop now and enjoy judder free. This works for me.

When you're done, simply press the power button on the rift. Your primary display will go back to the cached single display mode at 60hz.
Slaventsiy
Honored Guest
11 years ago
Tried the proposed solution, but not sure whether it's Windows 8.1 update or it's specific to Surface Pro, but it isn't possible to set the screen to unsupported resolution even from Virtual Desktop — they're all hidden and the "Hide modes that this monitor cannot display" is disabled.

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Win8.1 judder in landscape(flipped) [working WA proposed]

18 Replies

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