5K+ inside out positioning chip in backwards?


I have two other posts with other issues I’ve identified. This is probably related to my post about centering drift.

PiTool has a Horizontal Calibration button. I would expect that clicking on it would make the horizon of the game match the horizon your eyes expect inside the headset. Holding still and flat is obviously what you should do. However, if you tilt your head 45 degrees toward your right shoulder, shouldn’t it align the horizon from top left to bottom right in the real world so the horizon splits the horizon of your HMD? With my unit, it does the opposite. The game world is set to 90 degrees off of what I expect, as if I’m lying down on my side. Using the above 45 degree tilt to the right, and clicking the button, gives me a horizon which runs from top right to bottom left. I think my unit is bad or something between this and the drift issue I have.

Is anyone seeing similar?

@Sean.Huang @Alan.sun @anon74848233

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Added a couple team members to your post.

Look at the real horizon. Tilt your head towards your right shoulder. See how the horizon is high in the right corner of your vision and low in the left corner of your vision? So it should also be in your pimax…which it is?
Am I missing something?

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First off, I don’t see that I mentioned this is without lighthouses, but I should have.

Second, to answer your question:

  1. in the real world, with a level head, the horizon is horizontal. Tilting my head to my right shoulder makes the horizon run from bottom-left to top-right in my vision (or visa versa).
  2. in the Pimax, once horizon is set correctly, the above behavior is what happens.
  3. in the real world, if, once I tilted my head right, I could magically ‘calibrate’ the horizon to match the plane of my eyes, then the horizon relative to my body would run from the top-left to the bottom-right as if I had laid down on my left side
  4. in the Pimax, when I tilt my head to my right shoulder and click the ‘Horizontal Calibration’ button, the horizon should be aligned with the horizon of my eyes. It isn’t. It is 90 degrees off.

Does that explain it better? It sounded like you were talking about normal operation once calibrated, but I’m talking about the calibration itself.

Tilting my head less or more than 45 degrees from center adjusts how much it’s off. 90 degrees makes the world upsidedown.

There’s an accelerometer and gyro or similar stuff to tell the hmd where level is. I thought the calibration was for people where it seemed off to them for any reason, they can compensate and make it look right to them.
So as I understand it, you’re telling the hmd I prefer my “level” to be ‘here’ when you tilt your head and calibrate.
So tilting right, it still knows where true level is but you’re now telling it you prefer it like this with horizon from bottom left to top right. And it locks it in as that.
I think you’re thinking you should compensate to the other side and then calibrate and it would then balance out to what you’re looking for, but the headset is doing the opposite and taking what you’re looking at when the head as tilted as being the way you want the horizon.
I’m not sure of this, I’m trying to work out what’s happening. I think the way you expect it to work is more logical but it works the other way.
Or I still may not understand what you’re saying, sorry if that’s the case.


I think that whatever your eyes’ horizon is, that button should set the in-game horizon to it. Imagine you were disabled and you couldn’t keep your head level like the rest of us. The world should adapt to the tilt of your head.

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Here is what the expected calibration response should be.

EDIT: It depends on what kind of calibration they are doing. It could just be calibrating what your forward facing direction is (instead of the full calibration I showed above).

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I haven’t tried it but I believe it’s meant for you to put it on a flat horizontal surface to calibrate it to something parallel to the Horizon as a zeroing as @Flinnt suggests.

But would need someone like @Sean.Huang to verify as I haven’t needed to correct Horizon.

@Davebobman that’s exactly what I expected and the opposite is happening. At the Calibrate step in your image, supposing my tilt is 45 degrees, the horizon ends up being vertical instead. It’s like it’s wired backwards or something.

It would be helpful if someone else could run their Pimax without lighthouses and try what I’ve described.

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Absolutely right. If you put the Pimax on something that is actually flat, it won’t matter if it is wired backwards or not. Flat is flat. But even so, it seems like it should work like davebobman’s image.


It will depend. In the p4k this was added to correct tilted Horizon as some users had tge horizon slightly tilted.

Something for sure that needs some description aa to how it is used calibrates/fix.