Like the title says… I’ve found a YouTuber (Ohne speed - using vr racing sims) that crated a mod for the Open XR toolkit allowing us to crop the images (both eyes). The results are amazing:
Here I share a video I made to show you how great this mod is. The toolkit now is a vital thing in 2024.
You might dislike an aggressive config but you can try a little tweak there and get +10 fps easily.
Amazing! This is similar to setting up the Fov stencil in the Oculus debug tool, but it can now be used on Pico 4 and other headsets.
Yes! I’m getting solid 45fps at a resolution near native with my Pimax Crystal Light and now I can set almost everything to ultra. It’s a game changer to me.
I still want a 5090 
What about the ctd reports when using the FFR?
What does cropping the image actually mean? Are we talking about deliberately reducing our FOV to increase our frame rate? One of the selling points of the Quest 3 that I use, was that it increased FOV. It made for a more immersive experience and I wouldn’t want to give that up.
EDIT: I watched the video and yes, I see that is what it means. Good to know the option is there but I like my FOV and so will accept the reduced frame rate and detail level.
Cropping the image via FOV with Oculus Debug Tool has never made as big as difference in performance that some seem to report. It’s not a linear thing imho.
Even going down to 85:85 only improves fps performance by about 5%. Personally I hate low vertical fov because it reduced my cockpit view. Each to their own I guess.
For the purposes of motion smoothing etc.,
the edges and corners of the rectangular display behind the lens are not visible in the actual field of view, but they still use the GPU.
When you are not using motion smoothing etc., this mod cuts out the unused edges so that the GPU is not used.
I thought that was the kind of mod it was, but am I wrong?
FYI: Take a look @this thread. Mostly good experiences using the “updated” OXRTK.
This is not correct. What you describe is already avoided by what’s called “visibility mask” or “hidden area mesh”. You can see on your desktop view that these parts are already cropped, except on a headset like Pico which for some reasons doesn’t do it (it’s possible, this is just vendor/developer laziness).
What the mod is doing AFAICT is enabling something called “FOV tangent” that you can already do on Quest Link. It was partially doable with previous OpenXR Toolkit, but you had to reduce the resolution by hand after adjusting FOV, and it did not provide maximum gain if you changed the aspect ratio. L
This is IMO the “better” answer. What the FOV crop feature does is effectively further reduce your already small VR FOV, thus a significant loss of quality IMO. Sim racers (like the author of the mod) don’t care because according to them it simulates a racing helmet (with a rectangular reduced FOV).
Everyone is free to have opinions. All that PCVR is at this point is how can we compromise and reduce quality in order to get acceptable performance… not a great option IMO, when OG OpenXR Toolkit showed that things like Turbo mode are 100% free of quality degradation, and things like DFR can be very close to unnoticed (especially if done through quadviews).
As you allude to, opinions and thus choices in what to compromise vary.
For me reducing the vertical FOV in a Pimax OG, while maintaining horizontal FOV, without degradation of the image quality within that rectangle gives such a boost to performance in FS2024 is more than worth the compromise. I certainly do not perceive it as “a significant loss of quality”.
With FS 2024, users of high resolution headsets first had to cope with an FPS reduction of roughly 30% even on a 4090…a bitter blow, when in FS2020 things were pretty good. Then along comes DLSS 4 with its new Transformer model of upscaling, giving much better sharpness and other improvements even in Performance mode, but again a further noticeable drop in FPS (using same DLSS settings).
So with this new mod we can regain all of that loss, provided we are not bothered by a letterbox view.
For me, who has worn glasses all my life and so have also lived with a reduction in FOV caused by the spectacle frames, this is a piffling compromise. I have had cataract surgery and no longer need glasses for driving, but still need glasses for reading, computer use etc. I choose to wear glasses all the time, because I’m used to it. The top section has no correction for driving and distance viewing, the middle and bottom section is multifocal for closer work. The frames are similar to the ones below; wide, but not very tall. Users of varifocal glasses are initially nauseous, as there is a small sweet-spot that you have to align with. Meaning you move your head more than usual.
As you can see, I choose and prefer this crop of sharpness in real life, so a similar view in VR worries me not at all. The performance gains however are spectacular in FS2024, making up all that lost ground.
Thks for the explanation.
It was crashing anyway with me and I really dont want less FOV.
Just a shame that recently fovehead rendering makes the toolkit crash.
That was a good usable feauture.
Amazing that the sim runs so much better with youre software in VR.
Shocking that comapnies by asobo cannot do what you did for VR community.
Scary idea is it not. If youre app stops working well than VR will be a really shadow of what it can be.
Still gratefull what you did for the community.
Really appreciate it. You fixed VR for FS simmers. And still do, Bravo 
In my case, there was an unwanted area between the eyes. It seems that you can adjust this with the Right/Left and Left/Right items.
You can reduce it by a few degrees before the edges become visible.
Also, if you see artifacts near the horizon, turning off light shafts seems to make them disappear.
I’m on the Beta atm and fortunately, no crashes with the Toolkit in use, even with the crop mod and eye tracking FR.
This is the crop I’m using (with DFR turned off to show a clear image across the screenshot).
Full 4312 horizontal x cropped down from 5102 vertical to 3078. 65fps in the Magni Gyroplane.
As you can see I still have a good view of the sky and the cockpit.
Hey Matthieu… I agree with you but like I said in my video, there are some scenarios where you use a helmet like the Pitts, Extra, Edge and choppers. Beyond personal preference, with a very conservative crop, the performance boost is very noticeable. No comparison with the FFR results… and I personally think that is very distracting and ugly. Immersion killer.
I have a question for you: (actually two)
Is there any way to have any kind of method to exclude the corners to avoid rendering them? “Cull outer mask” HAM, is not working with the PIMAX Crystal Light. Am I wrong?
Turbo mode. Is this affecting Vsync? With the Quest3 I see the difference but not with the PCL.
Thanks in advance.
I dont recall whether Pimax exposes a HAM. I think they don’t on PC/PCL and the excuse was “the invisible area is very small on that headset”.
You dont need “cull outer mask” anyway with MSFS since that game implements HAM properly. That option is mainly for iRacing where the game doesn’t do it.
Someone could implement a HAM injector to have a custom shape. The FOV method is a rectangle and has no flexibility on that (a view frustum is always rectangular).
Turbo mode primarily addresses issues in OpenXR runtimes. The issue is severe on Quest since Meta isn’t doing any efforts for PCVR so their runtime is very broken when it comes to frame timing.
On PCL, you are either using PimaxXR or Pimax OpenXR (which is just PimaxXR repackaged). On my OpenXR runtimes, there is no need for Turbo mode since the frame timing isn’t broken like it is on Quest.
Thank you so much for the fast reply.
Are you ok with Ohne Speed’s mod? I don’t want to keep recommending something you don’t approve. Are these new features something you could implement or even improve?
My stuff is open source with a permissive license so yes I’m fine with people extending it, especially since I am not.
Unfortunately I fear this will create new issues like the whole digital signing problem, but there is no easy solution to that. As someone else mentioned, the fact that it carries the same name and follows the version scheme can mislead people, but there is nothing I can do about it.
I too wear spectacles in headset (PCL) and using foam spacers to keep from touching lenses. This already reduces FOV for me and since I’m on a RTX3090 I need the reduced pixel count to improve FPS. Target FPS is around 28-30 in FS24 and am achieving this by 90% vertical FOV, resulting in 4312x3564 while maintaining native resolution clarity. Without the mod FPS is around 18-20 using DLSS balanced and ‘K’ setting. I do not notice the FOV reduction and overall experience feels more natural and immersive.
