Accessory Temp Topic Crystal

Heliosurge · July 16, 2023, 6:27pm

Prescription Lens Options.

Heliosurge · August 4, 2023, 7:01am

Posted By Pimaxquorra on OpenMR

We’ve seen some creations with our Crystal on our Discord channel or on social media, with some of them seriously getting our approval. Here we share the best mods.

Side-charging for 45H battery life

Credit to: Cheezus-Crisp & Jason Lyon

You can basically get infinite battery life by using a 25W QC3.0 charger and a USB-C cable, and plug in the USB-C on the top right of the headset (normally used for firmware updates).

You can get a long cable and neatly fit it together with the DP cable so that it’s not in the way.

Headset foam for thinner faces

For smaller faces, if you want less light leakage, simply put in weatherseal into the sides of the facial padding. If you cut it neatly, it’s a pretty elegant solution!

3D print for more comfort

Credits to HeadsetHistorian

This comfort mod can be 3D printed, URL coming soon.

Using Index controllers

Credits: Dextro, Reinhard Roscher & Dextro

YouTuber and user Reinhard has this tutorial on how to use Index controllers with the Crystal, even without the lighthouse cover.
https://www.youtube.com/watch?v=ZAGt3wgaTBA

Comfort strap

Credits to: Omniwhatever

Even though Pimax is developing its own comfort strap (as an accessory), Omniwhatever also shared his comfort strap solution on Discord. This one is from StudioFormCreative:
https://www.studioformcreative.com/product-page/pimax-crystal-counter-balance-enthusiast-kit-100-gram

https://community.openmr.com/t/best-pimax-crystal-mods/41025?u=heliosurge

Heliosurge · August 4, 2023, 7:12am

Open Composite

Pimax OpenXR

Heliosurge · August 5, 2023, 9:59pm

Active DP repeaters

Recommended by Godas on Pimax Discord

Heliosurge · August 6, 2023, 12:40am

Thingsverse 3dPrintables

WallCrystal Wallmounts (HMD and Controller)

deadly100 posted on r/pimax

Heliosurge · August 12, 2023, 7:47am

Heliosurge · August 19, 2023, 2:39am

Pimax Crystal - You CAN extend the cable…

Posted by Adam_SimPorium on r/pimax

Cable Extensions Crystal

Just here to confirm what is working for me. I am only extending in both cases by a 1m Amazon Basics 1.4 DP cable. While I expect you can extend by more than 1m, if only a little, I haven’t tried to.

Using 5m cable and hub shipped with the Crystal. Powered DP repeater REQUIRED.

The hub already provides some extra USB cable length, so I only needed to extend the DP a little. The DP Repeater from Cable Matters works between the Crystal DP cable and Amazon DP cable. It is USB powered and I have just connected it to the same Crystal USB hub.

Using the 6m fibre optic cable with the hub. Powered DP repeater NOT required.

Used a 1m Amazon Basics USB 3.0 cable to the same Crystal hub. In this instance, a DP Repeater is not required between the Crystal DP cable and Amazon DP cable, only a noon-powered female to female coupler.

Links (not affiliate):

Cable Matters DP Repeater: https://amzn.eu/d/hwKItGZ

DP 1.4 Coupler: https://amzn.eu/d/1GHOKGf

Amazon Basics 1.4 DP Cable: https://amzn.eu/d/227bIOP

Pimax 6m Fibre Optic Cable: 6M Fiber Optical Cable | Pimax

Reddit Source

Heliosurge · August 26, 2023, 2:02am

[Crystal MOD]

Simple head strap mod for my Crystal

Posted By Excellent_Gur_8717 on r/pimax

Modded my Crystal with a BOBOVR M1 Plus Head Strap for quest2. I bought it on Amazon for less than 20$. Great improvement in comfort and stability. The design and balace of the factory head strap is good but the elastic band is stupid, and I think every Crystal user should replace it at least with an non-elastic one.

I have to narrow the back end of the band a bit using scissors so it can fit the hole above the battery. The bowl for the back of head is not necessary but it increases stability, and it can be fixed easily using tapes and ropes.

(“fixing the bowl”)

Posted on Reddit

Heliosurge · September 9, 2023, 6:39pm

Temp to organize info for optimizing prescript lenses with Focal length info on Crystal

https://reddit.com/r/Pimax/s/qSjbILpl8w

https://reddit.com/r/Pimax/s/Q8fibZNgd7

Heliosurge · September 10, 2023, 12:02am

@risa2000 Article on Canted Displays & Ipd pimax wfov hmds P2-Series (Artisan to 8kX)

Clarifying Near IPD x Distant IPD confusion

Quite a lot of users made an observation that when they set their IPD setting in Pimax using the method of “getting images in both eyes sharp at the same time, while focusing on the distant object”, the reported IPD by the HMD is actually significantly smaller than what is their real IPD.

Some started to believe that this is because “Pimax requires using Near IPD”. Just for the sake of understanding, let’s assume that by Near IPD I understand the interpupillary distance of the eyes when they are in the reading mode i.e. focusing on objects which are in reading distance. As reading distance is relatively short (~40 cm) the convergent nature of the reading look makes the eye pupils closer to each other (because the look has significant convergence). So the consequence is that Near IPD is shorter than the “normal IPD” (which some called “distant”).

While this is true, it has nothing to do with Pimax, because in VR, the environments and the objects, which are rendered in the virtual space, are very seldom viewed (and thus rendered) at the reading distance. In fact the VR guidelines suggests that things like UI should be rendered at 1-3 meters (closer to focal distance) to avoid some discomfort which comes from disparity of the focal distance and the virtual distance.

On the other hand in VR, while the objects cannot preserve their focal distance from the real world (as this one is fixed by the HMD design), they can still preserve the convergence property of the view. In other words, if my HMD is set up correctly and I look at something 3 virtual meters in front me, my eyes should converge in the exactly same way as they would if I was looking at the real object 3 real meters in front of me. This is ensured by setting correctly the rendering views for each eye in OpenVR.

I have already posted a long story on IPD and Pimax optics here Some thoughts on the IPD discrepancy - Pimax 8K Series - OpenMR | Community, so I will just reiterate some results here (for more detail, read my original post).

The Pimax optics is set this way:

image1380×744 33 KB

I drew the eyes this way just to give an idea how the different distances change along the optical axes, but of course you are not supposed to look into Pimax this way. You can however note that in order to align lenses with the eyes the distance between lenses centers must be higher than the IPD (which is 68 mm for the diagram). [On the side note, the eye size is supposed to be scale accurate, the distance of the lenses (and the panels) from the eye is arbitrary - they are probably closer to the eye, but I did not want to clutter the image]

When we look at things in Pimax, we are looking at them this way:

image1676×905 17.3 KB

Notice the slightly convergent look (in fact the eyes converge at the point which 1,5 m away and which is at the correct scale), but then this way they no longer look through the lenses centers, but through the lenses peripheral ring. This makes the image slightly unclear, because it suffers the distortion.

People however noticed that and started to decrease the IPD setting using the method described above (getting images in both eyes sharp at the same time, while focusing on the distant object), which led them to this:

image1676×905 18.1 KB

In this configuration the eyes are still focusing on the point 1,5 m away, but lenses are adjusted in a way that the eye optical axes align with lenses centers, which should give the clearest picture in both eyes. Also note what would the HMD report in this case as an IPD. 60,4 mm is much lower than 68 mm which is the nominal value, but the difference does not stem from the near vs far IPD, but from the optical design of the Pimax (divergent views).

The problem of this setting, while it may help with focusing the image, is that it screws up the angular fidelity of the stereo views, because the views are in the application rendered with divergent views (at 10° angular offset) but they are observed ~~dead ahead~~ at the different angle and through the lenses which are now tilted.

I hope I made it clear that the discrepancy in the IPD many observe when they try to set it by using the aforementioned method has nothing to do with the “near IPD” and while it may work for some it is definitely not a universal solution.

Originally posted on OpenMR

Heliosurge · September 8, 2023, 4:01am

Posted by Godas on Pimax

Got something interesting to share…this one can fully charge Crystal via the type-C with maximum power 20~24W

Amazon Canada
Amazon USA

For people run into any power issue, this maybe the final answer…
Also quick test bunch other 65W one as well, none of them works as well as this 100W one, maybe someone else got 100W GAN charger can test it out as well.

Cable

100W Gan Charger

Discord Invite

Source Discord

Heliosurge · September 11, 2023, 1:40am

Custom TPU Facial Interface

Posted By mynsmeisntgreggory on r/pimax

I created a TPU facial interface using a reverse engineered model of the Pimax Crystal and a 3d scan of my face. Similar to how Bigscreen creates their facial interface for the Beyond. I run a 3d print farm and if there’s enough interest I’d consider offering this as a service.

This is iteration 4, The image below shows the first 2 PLA test prints on the right. 2nd from the left is the first TPU iteration (had lots of print defects and was a bit too firm). Final iteration was printed in a better orientation with less infill.

Here’s a google drive link to the reverse engineered headset along with instructions for how to make your own if you have a TPU capable printer. I’m also experimenting with a resin printer.

https://drive.google.com/drive/folders/1O2yJUfuzjjDHens0J6RTw1aa_h-bmu0R?usp=drive_link

Source Reddit

Heliosurge · September 11, 2023, 1:53am

Some thoughts on the IPD discrepancy

By @risa2000

Following several posts on IPD settings problem and complains about the mismatch between measured distance between the lenses’ centers and the IPD reported by the headset I tried to figure out from where the problem comes and if it is even a problem.

I have been running recently some tests on ED and during those test I realized that it is relatively easy to play with OpenVR (using pyopenvr). I could get for example recommended rendering target resolution to prove that OpenVR applies the additional limit on the size which is not visible in the SteamVR UI (Elite Dangerous Setup Guide - Lets make it Dark Again :) - #131 by risa2000 - Pimax 8K Series - OpenMR | Community)

Another interesting info which one can get this way is what OpenVR calls Eye to head transform matrix by calling this function IVRSystem::GetEyeToHeadTransform.

This transformation matrix defines how the “eye coordinates” transform to the “head coordinates” and is used to split the original view (which would use the pancake version of the game) into the two views needed for stereo view rendering in VR.

When using PiTool in Compatible with parallel projection mode, the corresponding matrices read:

Left Eye:
[[ 1.        ,  0.        ,  0.        , -0.03486158],
 [ 0.        ,  1.        ,  0.        ,  0.        ],
 [ 0.        ,  0.        ,  1.        ,  0.        ]]
Right Eye:
[[1.        , 0.        , 0.        , 0.03486158],
 [0.        , 1.        , 0.        , 0.        ],
 [0.        , 0.        , 1.        , 0.        ]]
They look almost like an identity except the last column, which defines the translation and corresponds to the left and right eye offsets respectively. In this case it means I have my IPD set to ~ 70 mm and it is evenly split between the both eyes. (It is a translation defined along the X axis of the view space).

So far nothing new here, with the parallel projection enabled we are rendering to two coplanar views, which only differ by the shift along the X axis, the same way as for Rift or Vive.

image1676×905 5.07 KB

Then I turned off “parallel projection” and read the matrices again in the native mode. The results got more interesting:
        [[ 0.9848078 ,  0.        ,  0.17364816, -0.03486158],
mLeft =  [ 0.        ,  1.        ,  0.        ,  0.        ],
         [-0.17364816,  0.        ,  0.9848078 ,  0.        ]]

        [[ 0.9848078 , -0.        , -0.17364816,  0.03486158],
mRight = [ 0.        ,  1.        , -0.        ,  0.        ],
         [ 0.17364816,  0.        ,  0.9848078 ,  0.        ]]
This shows not only translation along the X axis (which is the same), but also a rotation of the views. To demonstrate how to figure out the angle, I use the following direction vector
look = [0.0, 0.0, -1.0, 0.0]
in Eye view of the left eye. The first three numbers are the coordinates (X, Y, Z) and the last one is zero, because I am interested in direction transformation and not coordinates transformation (by putting 0 there, the translation is omitted, by putting 1 there it is included). Then calculating the new direction vector in Head coordinate system gives:
mLeft x look -> [-0.17364816,  0.        , -0.9848078 ]
Since I know that the original vector had the length of 1, using this, the change of the X coordinate and basic trigonometry, I can calculate the angle of which the view rotated along the Y axis (this one does not change).
degrees(asin(0.17364816)) -> 9.999998972144015° ~ 10°
Which means that in the native “canted” mode, the views which the headset reports to the OpenVR are not parallel but divergent by 10° on each side.

image1380×744 33 KB

The visualization above is scale accurate to the eye size, IPD and the angle, but the placement of the lenses and panels are arbitrary, just to give an idea of the impact of the divergent property, notably how the lenses centers cannot be at the same distance as the eyes.

I also made an assumption, that the lenses are perpendicular to the optical axis (which corresponds to the view axis, reported by OpenVR) and that for the sake of a predictable behavior the lenses are positioned so that when the eye is looking through in the direction of the view defined by the headset, its optical axis is identical with the optical axis of the system.

Now it should be easier to imagine what happens when you set the IPD lower than what is your real one. The optical axis gets offset but the angle remains the same, so you get the lenses centers closer to the IPD distance, at the cost of getting the angular offset slightly off.

The another consequence of this design is that thanks to the divergence of the views, the sweet spot becomes dependent on the distance from the face as it is no longer invariant as in the parallel projection. In paralel projection, if you set your IPD right you can move the headset further or closer and this will only change the FOV, in “canted” projection, moving the headset further or closer also changes the position of the sweet spot as it may end up in front of or behind the eye pupil.

Originally posted on OpenMR

Heliosurge · September 16, 2023, 12:28am

Heliosurge · September 26, 2023, 2:02pm

Pimax Crystal comfort mod - facial interface

Posted by Sacapuces on r/pimax

https://www.printables.com/model/593764-pimax-crystal-comfort-mod-facial-interface-spacer

Since it was asked on another post, here is my solution to have a better/more comfortable fit for the facial interface

I’ll probably make a better version in the near future to eliminate some light leakage but this made the headset way more comfortable to wear for me (like the index)