Pimax 5k+, what does it mean ss=1? Why so many pixels?

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#1

Guys, please help me to understand super sampling better. I know how to change it, and how picture changes, but what is actually SS=1 (booth in steam and pitool)? I saw it is huge amount of pixels for ss=1, much, much more than native resolution of 5k+ display. How did pimax designer decided what should be 100%? And why horizontal / vertical ratio does not fit screen native resolution?

I know that pimax screen is only partially used, because of lenses (they should be better) and ipd adjustment. How many pixels are actually rendered, and how many are visible to us?

I ask because I play Il-2 Sturmovik, and there higher super sampling gives beautiful picture, but long distance contacts are less visible, blurry.
Before with oculus rift I could set ss=0.8 ( just a little bit more rendered pixels than screen native resolution), and spotting planes was the best then.
I was trying many ss profiles with pimax, but nothing helps. I feel like I can not find resolution without under/oversampling.

PS: I use pitool 180beta, paralel projection disabled, large fov


#2

Leave Pitools at 1 and Steam SS can be set to their auto. If you want custom it will vary by your hardware. The better card the higher you can go. I have a 2080ti and for demanding games set it at 3500ish horizontal … even though the aspect ratio is for the Vive and Index and doesn’t take into account the Pimax FOV. Yes the game will look better at higher SS but it will take a hit to your system. Find what works best.


#3

I think you missunderstod me. I know how to get the most beautiful picture in acceptable performance, for each game. Only in IL-2 there is another story; I can not see distant dots (planes) with supersampling. No mather how beautiful or ugly it is. I need info which resolution suppose to be between undersampling and oversampling picture? The “optimum” when game renders 1 pixel in distance, and I got 1 pixel in my pimax (in a sweet spot area).
In rift I found that easy, but here I can not. That is what I need.


#4

Perhaps the information you want is in one of these posts?

If you have any other questions, then you might find some more information here:


#5

Thank you. Now I understand, there is no correct and simple answer. Aniway, I think Pimax 5k+ put ss1.00 resolution too high, and I do not get why.

On end, I made tests in IL-2, trying different ss / resolution, until I found what feels right for me:

  1. “like_under-sampling” 2148x1764 (Pitool 1.5, Steam video 0.5, Steam app.0.4)
    The result is grainy, I do not like it at all.

  2. “like-no-super-sampling” 2400x1972 (Pitool 1.5, Steam video 0.5, Steam app.0.5)
    It feels like no super sampling. Or maybe a little bit. I can tolerate quality or such picture in hmd. I know it is not beautiful, but contacts far away are visible pixels,and it is not bad.

  3. “like-small-super-sampling” 2628x2164 (Pitool 1.5, Steam video 0.5, Steam app.0.6)
    It is much more beautiful than before, sometimes contacts far away are a bit blurry / I think ss starts to interfere with visibility of small objects.

I tried a few more values, and every 100 pixels more (in hor. and ver. direction) give more beautiful picture, and at same time it ruins the spotting of planes. There is no win-win situation here.


#6

Nobody outside of Pimax knows for sure and the values keep changing with every PiTool version. My main guess is that it has to do with performance optimization (or their attempts at it).


#7

The resolution the headset suggests at PiTool RQ=1.0 is an arbitrary value defined by Pimax, and basically means we hope this might give a good trade-off between the visual quality and the performance.

Then, depending on the application or your system, you might need to adjust it either way.


#8

Because of the way that lenses stretch the image, there is no 1 to 1 resolution in VR. The wide FOV makes it more pronounced, since there is a larger difference in stretching between the center of the image and the boundary areas. Basically, when the very center of the image is 1 to 1, the outer area might be something like 8 to 1. Even in the sweet spot, if the tiny central area is 1 to 1, the outer area of the sweet spot might be 4 to 1.

There is no way to change this effect, using current rendering techniques, although FFR (fixed foveated rendering) might help, since it under-samples the outer areas (but still won’t yield 1 to 1 pixels throughout the visual area).

Raytracing could actually yield a 1 to 1 image, by casting rays in a nonlinear fashion. That is, working backwards from the lenses distortion, rays could be cast 1 to 1 in the center of the image and at the edges, a single ray could map to 8 pixels in the unstretched bitmap, which would yield a single pixel in your view through the lens. Unfortunately, this raytracing technique would need to be implemented in the game itself.

The reason that Pimax has chosen the image resolution at Quality 1.0, is that in the opinion of the engineers that resolution had the “best” overall image, in a variety of applications (games).


#9

Check this out

It’s been updated yesterday. Follow it step by step, leave nothing out, and take a look. It’s the best of both worlds and lets you see targets in IL-2 at very long ranges as well. It took a while to find the setting. This is for normal FOV.


#10

Sadly not everyone see the same things in the same HMD.
SDE…Distortion…etc
All those settings can be good but not for everyone.

What I can tell you is to dont listen other ppl, just like many raising SS like crazies thinking they will download pixel in their HMD.
Try something and try the opposite.
For a year I was the only one saying I use Pitool 1.5 or more with SS auto or 30/40%, now other ppl find similar settings good also.