How to get the sharpest 2x4k images with a wide 200° FOV in PIMAX 8K

Hey there pioneers!

I’m backer n°998 and i’m very excited to see how things are shaping up lastly. Last goal is being reached with unexpected ease as I’m writing this, so PIMAX 8K will come with its eye-tracking module builded in ! YEAH, that’s SOOO COOL ! Cheers to that !

From the start of the campain we know that high resolution and wide FOV are conflicting somehow.
As a VR enthusiast, I’ve been always wondering how to get the sharpest image with a wide 200° FOV ? I’ve made some reseach about this and found out:

Projection method matters a lot for wide FOV as it can bring a significant boost to the sharpness in the center of the vision by “warping” the center part of the image onto more pixels and thus get the most out of the “8k” resolution with less distortions at edges.

With actual planar projection and wide FOV, peripheral vision gets a too large area displayed onto panels.
Here is what happens with standard planar projection:


That’s about 2/3 of the panel’s pixels beeing wasted because of distortions at sides.

Here is a comparaison beetween standard flat projection (planar) and curved projection (Panini) on 170° FOV :


You can see that curved projection renders better so there is no over-strech over the wide field of view.

Next: lens magnification. Once properly tailored for curved projection, such lenses will get the most effecient use of the angular resolution in the center of the vision.
In other words: with properly shaped lenses, curved projection’s rendering method will give a significant boost to perceived sharpness through them.

Q1: As far as this is a rendering thing first, is that under the reach of PIMAX’s software or even SteamVR or up to Unity, Unreal, Source2… to support it ?

If that’s in Pimax hands, here comes the next question:

Q2: @PimaxVR @anon23564932 @Matthew.Xu : With next prototypes V3,V4 and V5 beeing announced, can we expect a boost in image’s sharpness using curved projection method (Panini, equirectangular, mercator, Pimax custom…) along with new appropriate lenses ?
In that matter, please find some interesting read here : a paper (with math) about Rectangling Stereographic Projection or the search for the best curved projection models with less content distortion.

I want to insist on this topic before the campain ends because i do really think it’s a “game changer” considering to what it brings:
[ul]
[li]Get a VERY sharp image out of the 2x4k panels by maximizing sharpness in the center of vision where it counts really.[/li]
[li]Get the lowest ScreenDoorEffect possible[/li]
[li]Get rid of deformations at edges due to planar projection method limit[/li]
[li]Get a perfect 1:1 VR scale in the entire FOV[/li]
[li]less opical flaws, more GPU power driven to quality of content rather than compensating flaws.[/li]
[li]Now, couple that with integrated eye-tracking module and multi-res foveated rendering to lower the load on GPU(s) and we are good for very high-end graphics in VR. That will unleach possibilities for GREAT content and appeal more gamers and big studios in the game. Devs may get very interested with this.[/li]
[/ul]
That can boost VR market for sure. That’s all the ingredients we need to democratise VR and appeal the masses to it.

PIMAX 8k can be the best performance/price ratio of all VR HDM and hold the crown for a long time if they concentrate on what’s important:
[ul]
[li]sharpest image over the 200° FOV[/li]
[li]solid tracking with low latency[/li]
[li]stable 90 Hz refresh rate[/li]
[li]quality eye tracking module with foveated multi-res rendering to enable QUALITY content sustainable with current GPU(s)[/li]
[li]appropriate ports for the best image quality input possible[/li]
[/ul]

Your comments are welcome. I would love to discuss with you about this. Cheers.

My 2 cents.

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They matter when you try to compress FoV. Like the panini rendering, that indeed shows like 170 degrees but in reality it’s only a few degrees on your monitor. I don’t think that matters for VR.

Did you read the doc-ok article ? http://doc-ok.org/?p=1649

But we can use supersampling in the future right?

Maybe with volta cards or the generation afterwards?
WE can use ss 5.0x

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ye sure, but by that time maybe we already into the 8k native resolution or maybe standard 4k native resolution and upcoming 8k native per eye.

wishfull thinkin xD

Great article, very interesting approach of this topic !

Yes, forget supersampling for sharpening 4k stereo. What i meant was that the planar projection is the worse to use and whatever a curved projection is choosen, that should de facto enhance the pixel per FOV angle ratio in the center of the vision. Of course the lenses should be reshaped accordingly to this change in the respect of optic rules and physics limits.
But i do believe that optic/physics do allow for some more improvement there.

I agree with you that we’ll then have to wait until Lens Matched Shading (LMS) or Multi-Res Shading (MRS) find their ways into game’s engines but if PIMAX is ready for taking the full benefit from it, then that would be a long lasting VR market game changer.

I don’t believe SS will be viable solution at 4k stereo resolution for long. You’ll need so much GPU power that will not be sutainable for the most of us.
That is wasting a lot of GPU power to compensate optics flaws and we’ll also have a data bottleneck to solve transmiting those huge amout of pixels to the HDM screens.
Only fixed or eye-tracked foveated rendering and VR works lens-match shading can help GPU(s) to sustain the load for that.

Yes i read the article. Good one. But it was made on purpose for explaining why Tested’s reviewer percived some distortions at edges while testing V2 prototype.
Doc ok said he was ignoring lenses and lens distortion at purpose.

My reasoning is different and we know by recent reviews that that particular problem is almost solved now. Latest reviewer didn’t noticed it at all or not that much. Now, my purpose is to maximise pixel density in the center of vision.
For that, you need to include both on-screen’s projection and lens distortion changes in your thinking.

Good point!I will discuss with our experts and maybe need some further discussion with you. Thanks a lot!

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Hey bacon ! good to read… are you in Pimax staff ?

Anyway, here is a paper (with maths) about the search for the best curved projection models with less content distortion :

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Yes, I am the product manager. Thanks, I will forward to our experts.

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Hi,bacon.
What did Pimax experts say?

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Yeah ! That’s great !
Would be nice to know what they said especially if there’s good news ahead ! :wink:

I doubt they would change anything at this stage, while I don’t doubt that there are superior projection solutions out there, I don’t believe they can fine tune it enough without further prototypes, that is if they can find someone to do new type of lenses that are needed. They can improve pimax 8k, but not a lot of people will agree with the timeframe. The best they can possibly do is making lense module detachable and make improvements after the initial release.

Agree with Soul, since it is unlikely we will see major changes to the displays at this point, the best we can hope for is modular/replaceable lenses. That way, if there is some better projection method, it would only require a software update, and some new lenses.

Would be nice to get an update form bacon though

Sorry for late. yes just like Kons said our team needs to use V4/V5 to perfect the current lens design before moving onto this new technology. The related expert is all in our current solutions, but I think we can discuss after the shipment.