New pimax owner (lighthouse jitter?)

Hi, I trialled a vive pro 2 and pimax 8kx over the
weekend and was pleasantly surprised just how much the tech has come on since the original vr headsets like the original oculus.

After lots of testing | decided to keep the pimax. It took me a while to dial it in but once | did it was clearly the better headset. Oddly the vive struggled with clarity in the distance but was good close up. Whereas the pimax was clear all over with a larger sweet spot. There’s just so much more headroom in the pimax too; it’s the hardware (gpu mainly) that’s holding it back.

However, one thing i haven’t managed to figure out yet, is how to minimise the lighthouse jitter. I’m using the same htc 1 lighthouse that | used whilst testing the vive pro 2 and that was silky smooth but by comparison the pimax is constantly jittering a little and doesn’t seem as smooth when looking around. The frame rate is maxed at 90fps and doesn’t jitter at all in 9 dof mode. It even jitters when placed on a table!

Is this just how they are?

Any ideas how | can stop this from happening?

I’m mainly playing asseto corsa using the settings
below - and getting 85 to 90 fps.

Pimax / steam settings:

  • render resolution 150% (5660x4832)
  • large fov
  • balanced foveated resolution
  • smoothing off

Asseto corsa:

  • fps limit 95
    +anisotropic filterina x16
  • x2 aa
    +max world detail
    +effects quality / dof quality / glare quality all normal
    +heat shimmer off
    +mirror res normal
    +high quality mirror reflections off
    +reflection quality and frequency both low

Pc is aryzen 9 5950x on a rtx 3090

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… here’s a pic of where the lighthouse is atm. I tried it higher looking slightly down on a tripod but I think to tripod was making it worse because of how unstable it was.

Ps this is my temp rig location. It’s unfinished (beanbag :joy:).

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Wow youre getting 90fps in AC with Large fov and 150% (steamvr?) res? I just about get 60fps with Normal fov and pitool quality 1.5.

Anyway, about your base station, what is the wire going from it to what looks like a pc on the table? The BS should only need a power lead.
Does it jitter in all games/apps i.e. like in steamvr home?
Maybe that mantle piece looks like a better place for it?

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8kx owners : 8kx has tracking jitter ! How do you fix it?

Pimax : yes

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The game changer for me was using foveated rendering in pitool. It renders the centre of your image at full res and the edges much less, however I found because the 8kx has such a large fov you don’t notice this happening.

… I have the power lead and usb-c plugged in. Is this wrong?

I don’t experience tracking jitter with my 8KX.

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Foveated rendering, i forgot about that, i must try it.
I don’t think u need the usb-c lead plugged into your BS, I don’t.

Edit: yeh u shouldn’t have jitter. I’ve noticed mine do occassionally when i’m loading steamvr home (the scene with the lines into the distance and it says “home” but all jitter goes when i enter home or a game).

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I’ll try post a video later today of what I mean. It’s not terrible and once in a racing sim you can’t tell but I can definitely see a noticeable improvement by using the 9dof compared to lighthouse.

Maybe that usb lead is causing some interference so I’ll remove that too :+1:

Few things:
The layout of laser sensors on Pimax is different from Vive (Pro, whatever) and the shape of the headset as well. There is probably the 3D model of the layout somewhere on the forum (but probably impossible to find :slight_smile: ) to get an idea what actually your basestation could cover.

The placement of the basestation is poor for two reasons: It is low so most of the headset will be blocked, it is not fixed, so the rotational vibration of the motor will give it a jitter. The fixed mount is a must especially for the gen 1 lighthouses which sported 2 motors (but even for gen 2 LH with only one, it is definitely a recommended operation).

Apart from the basestation placement, Pimax headsets are known for having the sensors misaligned, which could also produce the jitter. It seems however fairly individual, so you might not be affected.

I would start with the correct placement and the mount. If you could borrow another basestation (and place it in the opposite direction) this could also mitigate some of the problems. In general gen 1 bases are pretty solid at the close range and in the setup of two of them properly mounted I did not have any issues with my original P5k+.

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Are you using the pitool fixed foveated rendering method in AC? Just tried it on “balanced”, it made little to no difference on my fps, it was definitely working as I could see the areas with less pixels.

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Hmm that’s strange. I gained 30fps when using that. And like you say visually it made little difference.

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What game did you test it in?

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Thanks, I’m going to order a second base station and see if that helps but first I’m going to take the usb lead out and fingers crossed it was that causing interference!

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Assetto Corsa. I’ve seen others say it works so i know you’re correct its just that for some reason on my pc it wasn’t really increasing fps…not sure why…maybe i’ll try again with “aggressive” setting. Its no drama anyway as i’m already quite happy with AC fps.

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I’ve setup the new light station so now I have two. The tracking does seem slightly smoother in steam home however ac is still showing some wobble.

I’ve been doing some googling and I think I have the same issue as this guy on YouTube (https://www.youtube.com/watch?v=plr2S3gogo4).

From the comments it seems to be specific to assetto corsa.

Any other recommendations for Racing Sims that work well with vr? I can live with the jitter but would like to make sure that my headset and light stations are not contributing to the issue before my 30 day return is up.

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I have project cars 2 and automobilista 2, they both work ok in vr but not as good fps as AC as they need parallel projections enabled. i bought mine on cd key reseller websites for a few £.

I would recommend some sort of clamp or other fixture which the base station is screwed into. I use a single version 1 bs (I mostly play VR while seated). I had jitter when my bs was sitting on top of a bookshelf, which was greatly minimized by using a camera mount which clamped to the bookshelf. It would probably be even more stable, if it were mounted to the wall. As an easy fix, I’d try clamping it to the edge of your fireplace mantle.

Why is a clamp needed? There is a rotating mirror inside (to pan the laser beam), which causes the entire unit to vibrate.

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Thanks for all your help and suggestions.

I just wanted to provide an update. After spending my entire evening last-night playing about with settings, it’s now truly amazing!

The jitter was caused by two main issues:

  1. only using one lighthouse - which caused the camera to stray occasionally.
  2. having pitool setup wrong for the game I was testing (asseto corsa).

I can now play asseto corsa with shader patch (most setting ticked) and sol mod with a pitool scale factor of 2, 8x aa and 16 anisotropic filtering whilst hitting 90fps with 24 cars on track! I’m so pleased with myself …. the wife, less so :joy:

What was holding me back was pitool smooth motion. The idea is when the fps drops below 90 it will limit fps to 45 for processing, then do some witchcraft and make it appear like running 90fps. Great in theory but for me it would make ac always run at 45 fps and hammer my cpu usage at the same time. With it off I managed 90fps constantly - i was even able to add lots of eye candy and still maintain this fps.

Happy to post screenshots of my ac settings if anybody is interested.

For reference I’m running an rtx 3090 on an amd 5950x.

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8kx has no jitter in BS 1.0 (or so small that it’s hard to notice), but 2.0 has it, and the engineer confirmed it
This is why I bought the 8kx and then sold it …

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I use 2.0 basestations, and I don’t experience tracking jitter. I’ve seen the claim that 2.0’s experience jitter while 1.0’s don’t a few times before on these forums, and I have a suspicion that this may have been true at one time but has since been fixed.

In fact, my impression is that there may be several Pimax issues which continue to echo around despite being out of date. Pimax doesn’t seem to post meaningful release notes, so nobody knows when they fix things.

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