Gnomes and Goblins preview

Well this was completely unexpected, and a very welcome surprise return for Jon Favreau and Jake Rowell’s Wevr title that seemed to have slipped into oblivion. I had played it again when I got my Valve Index last year but there had been no further updates or information since, like many early Vive demos that are still available but appear dormant in terms of development.

I always had fond memories of the Vive demo from 2016, but 4 years was a long time ago, especially in terms of VR software. So to find a “Venice” preview available at the festival was fantastic, and much more rewarding when I discovered in-headset that it wasn’t an updated Vive demo but something entirely new.

One problem I found with the original Vive demo was the requirement for a big room (to create a big play space) to get its roomscale VR to work properly. Without going into software and moving my playscape, an important trigger event could be just out of reach, often at home I’d find myself trying to flatten my Vive controller against the physical wall to try and reach something.

During the new Venice preview I used free locomotion, shook a fairy (don’t ask!), transferred through portals, paddled down a river on a raft, lowered myself on a rope platform down into a mine, explored a series of tunnels in an illuminating way, attended a meeting of many in a cave and finally released lanterns into the sky. Hundreds of NPC’s roamed about, some singing, many doing their own stuff, with gorgeous detail and animation. Overall an incredibly rich world, which felt like being inside a big budget Hollywood animation movie.

Performance took a hit, with strange microstutters in headset, despite my frame timing not averaging over 9ms/11.1ms (90hz) though the developer graph showed very thin yellow spikes in places. I tried adjusting super resolution without it resolving the issue. Textures seemed muddy and very “2016” in places, yet sharper in other places; close up interaction with NPC’s were richly detailed, longer distances were blurrier.

Something odd was going on, could be compatibility with the Index headset, though I suspect Viveport was not playing nicely with the new Windows update, or with SteamVR. Its not the first time I’ve had problems after installing Viveport, and was glad to uninstall it at the end of the festival.

I’ll need to play the Steam release at the end of this month to see if this problem reoccurs. The recommended specification demonstrates that this title will be perfect for the new wave of Nvidia RTX 3xxx graphics cards as its going to require some serious grunt to run well. For reference I’m using 8086K @ 5.2Ghz / RTX 2080Ti.

  • i7-9700K or equivalent
  • Memory: 32 GB RAM
  • Graphics: Nvidia Geforce GTX 2080 or equivalent

I’m not going to say any more as its better discovered first person in your headset. The full game releases on 23rd September 2020 and promises many hours of gameplay in its rich environment.

It’s not an exaggeration to say that Gnomes & Goblins is the biggest project Wevr has developed. Where the G&G Preview was a quick introduction to Buddy and his world, a bit like a tasting spoon of ice cream, this all-new, full-featured, multi-hour VR simulation game is like a full pint of your favorite flavor with new interactions and story moments to discover including new characters to meet, forest areas to explore, magical collectibles to discover and a range of open-world gameplay from climbing to paddle boarding to farming and brew-making.”Wevr

Thanks for reading! Rob Cole


Valve ear speaker teardown

Ever wondered what was inside those neat off-ear speakers on the Valve Index?

“Balanced Mode Radiator” (BMR) ear speakers use custom drivers made by Tectonic for Valve. Valve list their audio solution as having these characteristics:-

Built-in: 37.5mm off-ear Balanced Mode Radiators (BMR), Frequency Response: 40Hz – 24KHz, Impedance: 6 Ohm, SPL: 98.96 dBSPL at 1cm.

In use onboard the Valve Index headset, the BMR ear speakers are unrivalled in terms of sound quality and sense of spatial soundstage for VR headsets, Emily Ridgway and her team at Valve certainly worked some magic here!

After experimenting with the BMR ear speakers and different audio headphones, I kept using the ear speakers as their excellent audio combined with quality of life (off-ear, on-board) was a great combination.

During the past year I did need to RMA a number of ear speakers, Steam support were very supportive and shipped them all as advanced replacement, and didn’t ask for the defective ones back. So I obtained some spares…

2 problem developed:-

1. Unwanted speaker movement. This seemed to worsen after lots of active gaming in Pistol Whip and Best Saber. Over time the ear speakers stopped holding the set position, drooping during a session or sudden movement. It appeared that the mechanism spring force degraded over time/use.

2. Vibrating. A slow developer but eventually the speaker pods started to vibrate at higher volumes or on bass hits. Not a malfunction of the driver but the physical connection between the speaker pod and speaker arm. This is felt as a looseness (slop) with light finger pressure, it’s easy to wobble the speakers pods.

Despite these problems I continued using the BMR ear speakers and gave Valve some feedback to help with further iterations.

How do they attach?

These attach to the Valve Index headset using a circular ‘pogo pin’ mounting system retained by a single torx T6 bolt through the headstrap.

Pogo pin mounting socket on Index headstrap

I decided to teardown one of my faulty BMR ear speakers to have a good look inside.

BMR Ear Speaker removed from Index, ‘Pogo Pin’ mounting system on the right
Carefully removed plastic cover (glued), I pushed it open using a flatblade screwdriver through the open slot for the height adjuster
Sliding height adjuster at minimum, power cable routing accommodates movement of height adjuster
Sliding height adjuster at maximum
Pogo pin mechanism taken apart showing pogo pin springs, bolts, sliding plate and circular pogo mounting

Looking closely at the “pogo pin” system, it’s cleverly designed using the springs to apply pressure to the pogo pins (to ensure contact with headstrap audio pads) and also allow vertical adjustment of the speaker with enough resistance to prevent unwanted movement.

Perhaps these springs are stretching over time/use, as springs do tend to stretch, to a reduced clamping force allowing the speaker pod to droop. It may be possible to tighten the small bolts to increase spring pressure, or pad the spring with steel washers to achieve the same.

The Circlip in the image above locks the speaker pod axle to the speaker arm.

This axle socket has gone sloppy (flogged out) on several of my ear speakers allowing the speaker pod to vibrate at higher volumes or during bass heavy audio. I’m unsure how this can be resolved without a different type of fitting, or perhaps a polymer bushing.

Circlip removed from axle
Speaker pod removed from arm, at this point I cut the power cables
Carefully working blade around speaker basket to break glue seal
Finally! Speaker assembly coming apart…
Wire basket removed, showing foam damper covering rear of driver unit
Wire basket removed from ear speaker pod
Thick foam damper from rear of ear speaker
Inside face of foam damper with moulding detail
BMR Ear Speaker pod stripped as far as possible, the plastic moulding was heavily glued to the front ring and resisted considerable force
Power wires to driver hanging inside speaker assembly
Detail showing driver and some type of baffling
Carefully cutting away the plastic moulding to access the driver
Driver core and baffling
Outside wire basket and diaphragm of driver
Cut apart driver showing magnet, copper coil, power leads
Close-up of coil

More information on the Valve Index audio is found in this blog article

Thanks for reading! Rob Cole.


Valve Index : Headset Ergonomics

valve index ergonomics

Originally published by Skarredghost in October 2019. Edited to correct my original spelling errors and some images updated. All images copyright of unless otherwise stated.

Introduction by Tony @ Skarredghost:

“If you are interested in ergonomics in virtual reality, today is your lucky day. I host a guest post by Rob Cole, that will show you his journey in making his Valve Index more ergonomic, modding both the headset and the controllers so that they can accommodate perfectly the shape of his head and hands.

Rob first tried VR in 1991, and has become an enthusiast of the tech ever since. Because of his background in industrial design, he has always had a strong interest in the design and the ergonomics of the VR headsets. At Immersive Computing (see his Instagram account) he carries on this interest, exploring the technology always starting from the human perspective, putting the human at the centre of his experiments and analysis. This post is the result of such kind of experimentations on the Valve Index headset.”

June 28th was a key date this year for a group of Virtual Reality enthusiasts who received on launch day, the first delivery of the new “Valve Index” PCVR system.

As a member of this small group, who against the odds had managed to secure a pre-order on May 1st, mine arrived at 12.31 pm on the 28th leaving me with the afternoon for installation and my first session.

The excitement of opening a new VR kit cannot be underplayed, it’s like receiving something magical, but I kept cool and took some unboxing photographs to preserve the moment for posterity before the packaging got tatty and the controllers bruised from striking walls.

valve index box
Valve Index full kit in neat cardboard box

By early afternoon it was installed, base stations bolted high up, covering a useful 3.0 x 2.8m play space, generous for a domestic installation in London.

In preparation for Index’s arrival I’d already installed the “Aperture Hand Lab” and “Moon dust” applications so I could try out the finger tracking of the Index “Knuckles” controllers, which were plugged into cellphone wall chargers to bring them up to full charge.

It was now time to take a deep dive into Valve’s Index to see what it was all about and test out the 144hz mode, which I was confident could be properly explored by my PCVR rig using its overclocked 8086K processor and 2080Ti graphics card.

A long hot summer of RMA’s…

Valve box full kit
Lots of spares thanks to Steam support sorting my RMA’s

This article has been a while coming….2 headsets, 3 pairs of controllers and a right ear speaker since launch meant more time in meat space than I’d recommend to any VR enthusiast.  

Despite some frustration over time wasted and trips to courier depots, I gained a cool collection of Index boxes and unavailable spare parts including extra cabling and a spare facial interface; for one rare week I had 2 Index headsets (Indices!) sitting on my desk.

two valve index
Advanced replacement for my headset meant I had indices for a week

It was also uncharacteristically warm in the UK this Summer, so when Index was fully working it was confined to early 6-8am sessions before the day heated up. 

New product launches can be difficult with new components from suppliers not meeting agreed specifications, or new production line processes where small assembly mistakes can have big usability or quality of life impacts on the end user, sometimes requiring replacement through the RMA process.

As a small example, my launch headset arrived with the headset harness offset to one side due to improper assembly, which caused it to sit skewed on my head as the offset gap just got larger the further the headband was opened.  

After some communication with Valve, it was advised to force the ratchet mechanism by hand to try and balance the strap, which thankfully worked and did not seem to cause any permanent damage to the plastic internals.

Ratchet strap came from factory with offset spacing causing headset to sit twisted on head

The phrase “Early adopters always pay” has been proven right once again, but as active support is being provided (albeit slowly at times and with different results) and Valve’s manufacturing partners in the USA and China improve their Quality Assurance, we can move forward.

Downtime with reality can prove fruitful, so during the long hot summer of RMA’s I dove into the ergonomics and looked at the 3 key areas that were bothering me during my VR sessions:-

  1. Index Facial interface
  2. Index Controllers
  3. Index Ear Speakers

For this first article, we will concentrate on the Index Facial Interface; a later article will cover the Index Controllers and Index Ear Speakers.

Index Facial interface

Time to dive into valve’s new Index PCVR headset

Index arrived with a single, removable facial interface, fitted to match a full–width pad glued inside the rear of the headset harness. It looked great, with a premium fabric outer and a comfortable foam inner; something that pre-release reviewers had spoken about favourably.

In Valve’s own words,“The Face Gasket for the Valve Index Headset is made with anti-microbial fabric that is soft on the skin and ergonomically designed to distribute pressure evenly”.

valve index facial interface
Valve Index facial interfaces

The magnet attachment system was a neat idea, though perhaps a little understrength as it was too easy to accidentally knock the facial interface from the headset; the first time this happened to me caused a moment of panic that the magnet may have scratched the right lens, thankfully it hadn’t.

There wasn’t a different width interface or a spare interface provided, which puzzled me as the HTC Vive (a Valve collaboration) had shipped with both narrow and wide facial interfaces – the “wide” really a regular fit and the narrow for people with narrow faces. 

Interestingly, some digging around on the internet by Steam user “BOLL” showed a now archived Valve product webpage for the Index headset from 1st April listing:

   2 Face Gaskets (narrow and wide)

By April 30th he noticed the webpage had been edited to remove any mention of narrow and wide, leaving:

 Face Gasket

Not sure what happened during this period, if there were plans for narrow and wide that got cancelled, but at launch Index shipped with just one Face Gasket (or Facial Interface, if you prefer). 

Instead, there was a rear cushion provided in the box for smaller heads, a basic foam rubber piece which seemed at odds with the anti-microbial fabric used for the facial interface and rear harness pad. Perhaps a lastminute addition, and a welcome one to provide more fitting options, but also likely to trap heat and moisture against the occipital bone (rear of head) raising the in-headset temperature.

valve index rubber spacer
Rubber spacer provided with the Valve Index

I’d always used the wide facial interface on the Vive as I’d tried the narrow interface before without any success when I got my first Vive in early 2016. People have different width and shape faces so the provision of narrow and wide facial interfaces made sense to anyone with a basic understanding of ergonomics.

Looking closely, Index’s interface seemed to be slightly wider than the Vive narrow but considerably narrower than the Vive wide.

Having also used my Vive with thin 6mm face cushions and now struggling to fit my face properly into the somewhat narrow interface of the Index, I wasn’t impressed with the field of view which felt more like my Rift CV1.

The omission of a wide facial interface for Index seemed very strange considering the obvious effort Valve had spent improving the headset’s overall ergonomics and how important the facial interface is for correct fitting especially for such a precise headset.

I soon found that the “sweet spot” (optimum eye position, relative to lens) was similar to the Vive in that it was relatively small – demanding a precise headset fit to align properly. 

valve index sweet spot
In headset lens shot showing lens off axis (left) and on axis (right), demonstrating the importance of a good fit when using the Index

The incredible clarity that had been talked about in reviews is something I could see by removing the facial interface and holding the headset close to my face. This allowed me to determine the issue was not caused by the display system (I got great clarity with this method) but the physical interference of the narrower facial interface.

Fitting is best done with the harness lifted up and the headset held loosely against the face with one hand so the sweet spot for each eye can be aligned before holding the headset in place whilst tightening the top strap (weight bearing) and rear harness (stability) using the other hand.

As my previous article on ergonomics explained, the facial interface is the primary physical interface for a Virtual Reality headset, the secondary physical interface is the harness.

The headset’s facial interface and harness should ideally support the optimum position for the user in that headset and then “fade into the background” by not applying undue pressure nor cause skin irritation.

VR headsets require a good craniofacial fit to provide visual clarity and stereoscopy, for headset stability (especially during movement) and long session user comfort.

A good fit is very important when using a VR headset

The aim when designing wearable VR equipment is to make it ‘transparent’ to the user; remove any physiological barriers to immersion to enable users to achieve a strong sense of presence on a repeatable basis.

Unfortunately, in my case the facial interface just wasn’t compatible with my face, I was finding it difficult to get my eyes into the right position causing optical aberrations and mild eye strain.

The need for constant adjustment and overall discomfort was dramatically reducing my enjoyment of Index to the point where I considered selling it, but before taking any drastic action I started by looking carefully again at the facial interface to see what I could do.

After removing the facial interface from the headset, I held it against my face (as if wearing the headset) and noticed a sizeable gap between my forehead and the face cushion, large enough to put my middle finger in the gap. 

valve index face mask gap
The gap is very visible between foreground and cushion

I could reduce this gap by gently bending the plastic base plate against my head, but when the facial interface was clipped back into the headset there was no such movement.

Tightening the harness just pulled my face deeper against the foam without finding adequate support, I could feel the headset moving slightly sideways as the foam further deformed trying to accommodate the mismatch with my face. 

One side effect was a black shape (display edge) noticeably present in my left eye but not in my right eye, to prevent this intrusion I had to dial the eye relief further out, further reducing the field of view.

I could get the position almost right by really forcing the headset’s position on my face and manipulating the headset harness but any tether movement would cause a shift unless clamped so hard it started causing craniofacial discomfort (i.e. sore face and headache).

With a slightly larger left cheek (zygomatic) bone than my right, I noticed that every time I tightened the headset it moved left, moving my left eye further off the sweet spot.

All humans beings display asymmetry which is perfectly normal, in fact there are few if any humans with perfect symmetry, which is why computer generated characters with symmetrical faces have an eerie “uncanny valley” effect.

Uncanny valley effect in action (image by Creepy Girl)

From my ergonomics work with performance athletes, I have not yet met anyone with perfect symmetry as all of my clients required adjustments to their equipment to accommodate their natural asymmetry in an effort to improve performance and minimise the risk of injury.

We are all asymmetrical whether it’s our hands or feet being slightly different sizes, the very common trait of a leg length discrepancy, a larger ear or a dominant eye.  In everyday life, we learn to accommodate these discrepancies and rarely consider them (you might find one shoe is tighter than the other) but in more specialist situations like fitting a VR headset it can become a problem depending on the amount of asymmetry.

My accommodation for this width mismatch is typical, there is a tendency to offset to the dominant side whether it‘s a VR headset or bicycle saddle – with a wider facial interface my asymmetry is present but does not cause such a radical shift in position. 

Additionally, as a “sample size” person (medium everything) I’m certainly not an outlier in terms of size; this left me wondering if the Index’s interface did not fit my somewhat average sized face, what about everyone else? 

Searching the internet, nothing wider was yet available from the after market companies as Index had just been launched. The only product I could find coming soon was VR Cover’s soft cover, which just wraps over the existing Index facial interface actually reducing the width.

VR Cover’s soft fabric Index cover (image by VR Cover)

I reached out to Valve and was told “Steam support does not have any information on when or if a new gasket will be made available.

I reached out to VR Cover and was told: “The team is still exploring several solutions for the Valve Index, so I’m unable to confirm if this is being developed. However, I’ve passed your suggestion on to them.”

So I continue using the Index as various RMA play out, but continue to struggle with my fit, “chasing the sweet spot” with moments of success followed by constant adjustment. 

I was seeing huge potential in the Index marred by frustration at my failure to find a good fit and the face cushion was starting to degrade with foam compression and ripples appearing in the fabric, not surprising considering the facial mismatch I’m asking it to try and accommodate. 

A wide face cushion emerges

Soon though, there is news of CAD files for Index being released by Valve, which includes a facial interface base design suitable for 3D printing. Excitement grows, files are released, the modding community is energised. ‘Boosters’ are also featured in the file dump, but more on those later..

Valve Index CAD
Example of CAD file released by Valve (Image by Valve)

Within days, I find a modified face cushion base which has been widened and released by Anonymous Hermit under the Creative Commons license.

It’s on Thingiverse and I quickly used my smartphone to try some 3D printing suppliers in the UK with the cheapest quoting nearly £250 (!!) but then discover Ninja Prototype who have a longer lead time but only want $33 including shipping from their Chinese print shop; it’s looking promising, there is hope yet!

RMA continues for controllers with joysticks not clicking in all directions so I purchase an Xbox controller and spend VR time driving cars way too fast in Assetto Corsa, and hearing voices in my head during the mindbending trip that is Hellblade : Senua’s Sacrifice. 

This period of seated VR proves useful to start experimenting more with the fit without the constant tug of a headset cable threatening to pull the headset out of alignment. I try using it without the face cushion by stacking strips of soft Velcro fabric; crude but very promising as it confirms the headset can easily cater for a wider face with the right interface. I also have some ‘wow’ moments of optical clarity which confirm the potential. 

valve index ergonomics
Experiments with Velcro proved a wider facial interface could work

During the Steam summer sale, I learn Valve is giving me a load of credit on Steam at the end of the sale as a reward for the Index purchase. I get a free pack of Index face cushions and some VR games… thanks Mr. Gabe!

Now with 4 face cushions (1 left from a headset RMA) I am free to experiment, so I quickly strip the worn original down to see what’s inside, interesting to see no doubt, and I salvage the nose gasket from it as I have just received notification my 3D print is arriving this week from Ninja Prototype. 

Valve Index facial interface strip down

Previous experience modifying headsets includes the original HTC Vive and Google’s original Daydream, so I check my Amazon account and quickly find some old orders for aftermarket face cushions and industrial strength Velcro I can use to secure the cushion to the 3D printed plastic base. 

Ninja Prototype deliver on time providing me with a very stealthy looking 3D printed facial interface base.

3D printed wide facial interface base by Ninja Prototype

I source slightly stronger N42 Neodymium magnets from Amazon and use an epoxy adhesive to bond each magnet firmly to its mounting turret, making sure they are leveled and centred. After the epoxy has cured I lift the print to the headset and it snaps into place with a satisfying click; the magnetic attachment is working as intended and now more resistant to accidental knocks. I carefully glue the nose gasket poached from the original Index facial interface in place using a special “gel” Cyanoacrylate which does not run.

valve index ergonomics
Gluing magnets on the new face mask

Turning my attention to the facial interface base, I wipe the surface with isopropyl alcohol, letting it evaporate in preparation for fixing the male-pattern Velcro that will be used to attach the aftermarket face cushion to the plastic base. Disposable nitrile workshop gloves are used at all times to prevent any skin oil or grease contaminating the bonding surfaces.

The first tricky part is cutting the Velcro to fit, which will require using as few pieces as possible to minimize any side shear from peeling the Velcro off when adjusting or removing the face cushion. Normally, the Velcro is a single piece, machine die-stamped using a cutting pattern, but I don’t have that luxury. 

To generate a cutting pattern I stick masking tape on the rear of the Velcro’s adhesive tape cover, so I can hold the Velcro against the base and use it as a template to draw a pencil outline. Adjusting for height, I eyeball it and carefully trim the Velcro with sharp scissors and check by placing each piece against the base. 

Making the mask…velcro fitting

I end up with 4 pieces, long strips top and bottom, small pieces left and right, I radius the corners to remove sharp corners which can get snagged and lifted when opening and closing Velcro attachments. 

The second tricky part is actually fitting the face cushion to the Velcro on the plastic base, its hard to centre and mount with equal spacing around the perimeter. Normally, facial interfaces and face cushions have a locating key to help with this, but we are freestyling here...a couple of attempts later it’s looking good. 

Wide facemask on the Valve Index

It’s now time for the “moment of truth” so I click the wide face cushion into place, give the lenses a quick clean, loosen the headset harness and lift the headset onto my face, just one word slips out of my mouth: “Wow!” 

Immediate thought is I’m back in a Vive but with more vertical FOV and slightly more horizontal, crisp edge to edge clarity and much higher resolution. The lenses and the display feel very different to the Vive Pro, it’s an impressive upgrade no doubt. I remove my new facial interface and do the “gap test” again, this time it‘s a great fit.

No annoying gap anymore, a good fit for my 59cm head

I hold the headset to my face with my left hand, before adjusting the harness; I try moving the headset around to find the right alignment to give each eye the best presentation. I carefully set the IPD and manipulate the eye relief adjuster until it looks and feels just right, using a variety of different scenes, the Real O Virtual test background and left/right eye checks.

Just as with my Vive, I need to rotate the headset slightly clockwise (from my POV) to raise the lens sweet spot to meet my left eye, like many humans my asymmetry includes one eye (my left) that sits higher than the other eye (right) on my face. 

With these adjustments set right, I notice the black shape is now missing from my left eye, and only appears equally on the edges of left and right eyes when winding the eye relief so far inwards the lens edges actually touch my eyebrows, so I wind out 2 clicks until there is no contact. 

To increase the FOV without the lenses hitting my eyebrows, I look at my face cushion, it’s slightly obscuring the edges of the eye box, so I try repositioning it on the plastic base. The HTC Vive had a smaller eye box so it‘s not surprising the after market cushion is not a perfect match for the Index’s larger plastic base.

I resort to cutting up an aftermarket face cushion, and manage to carefully fit it as 3 pieces, with some Velcro tape securing the cutting gaps on the rear of each piece.

Modifying the face cushion to increase visible FOV

Now it’s opened up the eye box, and I am getting the full-fat FOV that the Index can offer. It’ss also extremely comfortable with an equal level of gentle pressure across my face even when tightened. The headset has a stability I have not had before, requiring less tension on the harness to stay in place. The headset now offers good support from having the correct interface and has become much more comfortable with no need for constant adjustment.

I also quickly realise with the magnet mounting system that fine tuning of the fit is possible to further address asymmetry so I experiment with “stacking magnets”.

magnets valve index fit
Magnet stacking for fine tuning of Index face gasket

In addition to the strap pivot on the headset block, it’s also possible to also change the display plane angle relative to the eyeballs with this method as well as the rotation of the interface relative to the face. After many experiments, I found that 2 magnets on the top right and lower right mounts provides a very interesting result “cleaning up” the display in my right eye by taking away a fine slight fuzziness – I suspect caused by my eyes sitting at different depths in their orbits (eye sockets).

Its a very interesting process and adds a big advantage to Index for modders, it allows some adaption of asymmetry without resorting to expensive 3D scanning of the face to custom print a personal facial interface.

valve index wide face mask
Valve Index with wide face cushion about to be worn

Firing up SteamVR I spend hours in Valve’s “The Lab” at 144hz and with super-sampling cranked up to 2.5 (the advantage of using a 2080Ti GPU): I’m just marvelling at the clarity, small details and unreal sense of presence. Whilst kneeling to look at the sides of the arcade cabinet, the robot companion dog runs up to me and I am so startled I fall over (thankfully onto the rubber floor in my VR room).

Glorious presence in the Valve Index

Speaking of presence, with physical discomfort removed and the optical system now aligned, I soon realise the “secret sauce” Valve has baked into Index is the high frame rate and ultra low persistence; the virtual world has never looked and felt so real, with noticeable jumps between 90hz, 120hz and 144hz.

The Index is doing a great job of tricking my subconscious “lizard” brain that this is real, and I’m feeling a level of presence I’ve never felt in any other VR headset, it‘s hard to describe, it feels incredibly vivid both spatially and temporally.

Perhaps Norman Chan from Tested said it best, “I didn’t know you could get so much more out of 120, 144 hertz and feeling more present until I used the Index. With 120 and 144 hertz its like I’ve downed 2 cans of Coke and I’m hyper aware”.

My job here is done, the wider facial interface works and is letting me exploit Index to its true potential and revel in strong feelings of presence. However, I know from previous experience that cutting up face cushions is not a long term solution as they tend to degrade from having unsealed edges and cut foam, loose fabric, etc.

The standard Index interface (top) and the modded one, note the big difference in radius

The wide option certainly works, but the next step is producing a commercial version that can withstand daily use. Another angle would be a “gamer” version with slightly firmer padding and more moisture resistance designed to stand up to the rigours of long session, active room scale gaming and allow for quick cleaning.

For now I’ll keep using my wide prototype, enjoying my Index and experimenting with alternative face cushions. As can be seen in the image below with the eye relief wound all the way inwards, I now have equal balance between left and right sides of my face as witnessed by the equally placed sweat contact marks on the top of the lens surrounds. 

Sweat inside the Valve Index

This success of this interesting experiment (which I encourage other Index owners to try, even as a stop gap measure) leads to a simple question aimed at the manufacturers, specifically Valve but also the aftermarket companies:

“Please can you make a wider facial interface for the Index?”

Final note: Community reactions

Since starting to write this article, comments have appeared from Index users on the Valve Index Subreddit which demonstrates the demand: (of course, I have removed the usernames):

-“They also need to release wide face gaskets a.s.a.p…many users are out of luck with the stock gasket and have to print their own”.

-“My face can’t take any more”.

-“This is a very strange omission from the Index HMD. I mean the Vive had it. Does Valve think that all of the wide-face consumers don’t buy the Index? It really limits the fov due to keeping the lenses further away”.

-“Valve is expecting 3rd parts solutions to cover this, no one is even saying they are working on one.”

-“I have seven, wish they fit my face tho :/”

Thanks for reading! Rob Cole, immersive_computing

“I hope you enjoyed this deep dive in VR ergonomics. If it is the case, stay tuned for the second episode of the series and feel free to contact Rob to talk with him about ergonomics in VR! (Or contact me asking me to put you in touch with him…)”


The importance of ergonomics in VR

Originally published by Skarredghost in August 2018. Edited to correct my original spelling errors and some images updated.

Introduction by Tony @ Skarredghost

“I always say that most of my readers know VR far better than me. For sure this is the case of Rob Cole, that you surely know because he comments a lot on this and other VR blogs

Rob first tried VR in 1991, and has become an enthusiast of the tech ever since. Because of his background in industrial design, he has always had a strong interest in the design and the ergonomics of the VR headsets. 

At immersivecomputing (see his Instagram account) he carries on this interest, exploring the technology always starting from the human perspective, putting the human at the centre of his experiments and analysis.

In various comments he has written, he has highlighted his expertise regarding comfort and ergonomics of virtual reality headsets and how these characteristics are important to:

  • ensure the correct presentation of the virtual world to the user by ensuring optimum optical alignment
  • ensure the headset does not interfere with immersion by causing discomfort, even for longer duration sessions.

I found the topic very interesting, so I asked Rob to write something for me about it… and so, here you are with a very interesting post on VR ergonomics. Have a nice read!”

I’m at the technology store today in my local shopping mall because I want to get a new VR headset.

The latest model by “Virtual Dream” was released a few weeks ago, but I’ve had to wait until the end of the month for payday. I approach the sales assistant manning Virtual Dream’s in-store concession, he sees me coming and greets me with a friendly “Good morning!”

He’s already noticed I’m looking keenly at the new headset inside the display case to the right of his booth, and knows what I’m going to ask next.

“Have you got time to do a fitting?” I excitedly blurt out, and he nods enthusiastically before replying, “That would be a pleasure, however, it will take about twenty minutes to print your face mask if that works for you?” I tell him that’s ideal as I need to get some breakfast, so I’ll come back and pick up my headset once I’ve eaten. 

He asks how I’d like to pay, and I swipe my phone across his terminal, taking a third of my pay cheque. “Okay, if you can come around to the left side of my booth we can get you measured up”, he asks, “You might have seen this online but it’s pretty cool to try out in person” he adds.

On the counter of his booth is a small camera attached to a circular support frame, with a padded chin rest. He gestures for me to lean forward, and after I place my chin on the rest, he lowers the frame over the top of my head. “Please keep as still as possible, and make sure to keep your eyes closed” he suggests, before pressing a button on the rear of the camera. 

I hear a gentle whirring as the camera moves around my head, and less than ten seconds later, my 3D scan is captured, “That’s all done, we got a great capture here. Okay, your circumference is 58 cm so we recommend a medium, and your head shape is ideal for the Y-style harness”.

He picks up a tablet computer from the counter, and makes a few keypresses before turning back to me, “That’s all done, if you want to come back in about twenty minutes I’ll have it boxed and ready to collect.” As I walk away to find my breakfast, I hear the 3D printer starting to do its work.

“I returned my ******* because of the discomfort and bought a ****. The ******* didn’t fit properly and hurt my forehead after 30 min. Really wanted to keep the ******* but if I can’t wear it, there’s no point”.

“The *** was super uncomfortable for me and gave me a headache, whilst the original **** was very comfortable for me, especially once I got the ***”.

“I literally couldn’t go more than half an hour on the ****** without getting a nasty headache, so I can’t say if you will like either, you should try and demo one first before buying?”

“The **** just made my head hurt, and I found the controllers too small (I have large hands), but the **** fitted great and the controllers were way more comfortable.”

These are all real responses on a virtual reality forum after posters have asked: “Which headset is best?”…only the names have been changed to protect the innocent headsets. 

One person recommended headset X because they found it fitted them well, whilst headset Y was a poor fit that they found painful to use during longer gaming sessions.

A second person has replied with an answer that is the opposite; they thought headset Y was fantastic and spent hours using it, whilst headset X had them quickly reaching for the pain killers. So who is right?

Actually, both of them are right, based on their “headset fit”, or more specifically their “individual craniofacial anthropometry”, the technical term for the measurements that are used to describe the human head and face.

When you start looking closely at craniofacial anthropometry, you will see a wide range of variance and facial asymmetry, as there are few if any people with perfectly symmetrical faces.

And this is where things become more complicated when designing consumer equipment like virtual reality headsets, as there are few other products on the market that are worn so intimately against the face whilst secured to the head.

virtual reality headsets ergonomics

Other examples are scuba diving masks or full-face motorcycle helmets, although neither of these have the added complication of housing a head-mounted display that relies on a good fit for the correct optical presentation of the display to the eyes.

Historically, virtual reality systems were prohibitively expensive and were limited to being used in controlled conditions by a small number of researchers, scientists, and groups like astronauts. 

It was typical to customize headsets to suit these users, just as space suits were made to fit specific astronauts. Additionally, the headsets were used for task-specific work purposes, where comfort would take a back seat to the task in hand, and the duration of sessions was often short.

Image result for nasa vr
Astronaut training at Nasa used VR (image NASA)

However, following the release of consumer equipment like the HTC Vive, Oculus Rift, Sony PSVR and the various Mobile VR headsets, we now have a different situation with a much larger group of people (the general population) using virtual reality on a regular basis, for longer periods of time.

The larger this group of users, the more craniofacial variation is found, which has a direct impact on the quality of the virtual reality experience and whether users continue to use their headsets on a regular basis.

Oculus Rift CV1 has been used by many different people

A “good fit” is comfortable to wear and ensures that the optical presentation is correct to truly immerse the user in their virtual world.

A “bad fit” is uncomfortable (can be painful) and often causes a poor optical presentation which breaks immersion. A bad fit is simply a bad fit and not something that can just be easily adjusted away with headset straps or fiddling with the IPD (interpupillary distance) adjuster. If it doesn’t fit properly, it won’t ever fit properly, like a pair of ill-fitting shoes that don’t get better with time but continue to cause problems.

A bad fit can cause physical fatigue to the soft tissue of the face and hard bones of the head, creating stress which makes the experience unpleasant, and can contribute to a tendency towards motion sickness especially when combined with heat inside the headset.

A bad fit with poor optical alignment has a negative effect on the feeling of immersion and presence as it interferes with the suspension of disbelief, by constantly reminding the user they are wearing a headset – its hard to relax into your experience when one of your eyes is slightly out of focus, the stereoscopic effect is reduced or you have noticeable lens artefacts in one eye and not the other.

virtual reality headsets ergonomics
One Vive Focus worn by three different people

A number of headsets currently on the market have no IPD adjustment, or software-based IPD adjustment (with a fixed lens), neither of which give suitable optical alignment unless you are lucky enough to have the same IPD as the headset.

As an example of IPD variation, in men the 5th percentile for IPD is 58.5mm, the 50th percentile is 64.0mm and 95th percentile is 70.0mm, therefore the mean (average) is 64.0mm.

Using a headset with incorrect IPD can be “interesting” to say the least, and in my opinion why fixed IPD headsets should not be on sale as it’s detrimental to the user and their experience of VR unless lucky enough to have a similiar IPD.

The end goal when designing Virtual Reality equipment is “complete transparency” where it fits so well, you don’t notice you are wearing it; you simply relax into the virtual world with true immersion where you feel “present”.

As we start to see higher resolution displays coming to market, the notorious “screen door effect” will diminish, and more sophisticated lens designs will reduce or eliminate optical artifacts like “god rays”, meaning that good fit will become ever more important so as to not become a barrier to true immersion.

An interesting aspect of our ability to accommodate new experiences is a psychological trait called “bohemian adaption”, where something novel soon becomes the new normal, causing us to seek further novelty as we become dissatisfied with the normal.

A side effect of this is our ability to overlook flaws becomes diminished once novelty wears off, something many VR enthusiasts have experienced once they become accustomed to their equipment and start noticing the flaws, which start breaking immersion.

The headset that had the “wow!” factor soon become irritating because it puts pressure on the forehead, their left eye always seems a little out of focus, their left hand gets a cramp when using the controller, or they keep getting entangled in their tether. Good ergonomic design seems to reduce or eliminate these concerns, and good ergonomic design relies on good data.

virtual reality headsets ergonomics
One person wearing Rift CV1, PSVR and Daydream

When designing equipment, an “Ergonomist” (human factors design specialist) will look at anthropometric data. 

To suit the general population we’d look at a range from the 5th percentiles to the 95th percentiles of the dataset, which will then suit 90 percent of the population, and accept that people outside of these percentiles will not be catered for by that design.

This anthropometric data has been gained by measuring huge numbers of people over a number of decades through large studies by many organizations including those in the medical profession and the military.

As an example, a functional arm reach for “5 percentile female” is 73.5cm whilst for “95 percentile male” is 94.2cm. This difference in reach of over 20 centimeters is one example of the wide range seen in the human population, and variations are also present in craniofacial measurements.

As the old saying goes “You can please some of the people some of the time, but not all of the people all of the time”.

The aim is to please as many people as possible unless you are aiming your product at a specific group of people using a specific dataset, as there are different sets of anthropometric data to target different groups of consumers.

Some examples would be general datasets for Men, Women, Adults, Children, or more specific datasets, for example, Caucasian or Asian. Appropriate anthropometric data is a critical ingredient for good ergonomic design, but data can be limited for smaller population groups which have not been widely studied.

virtual reality headsets ergonomics
Each headset has its own design of facial interface

Companies like Oakley manufacture their sunglasses in “Regular” fit and “Asian” fit, as do a number of bicycle helmet manufacturers.

You will also see different “foot forms” used when designing shoes for a Germanic foot, Celtic foot or Greek foot, just to name a few of the different foot shapes found across the human population.

The companies that manufacture VR headsets choose a particular dataset (head model) when designing their headset, and will make design choices or compromises to try and suit the largest possible user base of their target market.

If you fall outside of this dataset, or have unusual features (as many of us actually do), you may find your headset is uncomfortable, slightly blurry or even painful to wear. This explains why a VR headset designed for the Asian consumer is often a poor fit for a Western consumer unless you actually better suit the fit of an Asian headset.

You can now start to understand why there are different opinions on VR headsets, and why it’s difficult to recommend a particular VR headset to a friend, colleague or stranger on the internet based on your own experience of wearing that headset.

A problem with the different “fits” that the current headsets have, is that you may want to choose a particular model based on its technical features, access to its content, or wish to support that company, but you might try or buy that headset only to find it doesn’t fit you properly.

Modifying Daydream to improve comfort and stability

Within each headset design, there is only a little that can be done to adjust fit, apart from some of the radical modifications people make. These tend to be “band-aid” fixes that only partially resolve fit issues to make that headset into something that can be tolerated, other fixes involve severe modifications that void the warranty which is less than ideal on an expensive headset that is only 2 months old. And sometimes the official upgrades can make the fit worse, for example, some Vive users bought the DAS only to find it much less comfortable than the original soft harness.

virtual reality headsets ergonomics
Three models of HTC Vive, three different form factors

You might have heard the word “ergonomics” when people discuss virtual reality headsets, such as “that headset had poor ergonomics!”. It’s a slight misuse of the word, as the definition of ergonomics is:-

“Ergonomics (or human factors) is the scientific discipline concerned with the understanding of interactions among humans and other elements of a system […] in order to optimize human well-being and overall system performance” (International Ergonomics Association)”.

Ergonomics is also known as “biotechnology”, “human engineering” or “human factors engineering” and has played an important role since the introduction of desktop computing in the office, where workers often spend hours doing repetitive tasks with a limited range of movement.

An Ergonomist is a specialist in the applied science of equipment design, intended to maximize productivity by reducing operator fatigue and discomfort.

As we move into the realm of immersive computing, the focus of the Ergonomist will shift from the desktop computing environment to the immersive computing environment which we access through virtual and augmented reality headsets.

This in itself presents a new set of challenges, ranging from equipment design to user interface design, and physical movement limitations inside virtual environments.

So what can be done to ensure headsets (and hand controllers, which we have not even mentioned) are comfortable? It’s a tricky problem to solve, as during the early adoption of consumer VR the development budgets are limited by the small size of the market.

This doesn’t leave much room to spend money on tackling difficult ergonomic challenges by offering a headset model with different “fits”, or providing much in the way of customizable or modular headset designs.

Improving comfort for the forehead

Magic Leap’s first AR headset has just come to market and shows some interesting thinking as its’ offered in two sizes, as well as each size coming with a “fit kit” offering a number of shaped pieces for the nose and the head padding.

This AR headset is different to VR headsets in that the waveguide technology does not allow for moveable displays to adjust IPD, so they’ve had to offer 2 headset sizes to accommodate users with a smaller IPD range and users with a larger IPD range.

However, if we run with this thinking, it could be possible for a manufacturer of VR headsets to offer different sizes, just as bicycle helmets are often available in small, medium and large sizes.

The current “one size fits all” model of the headset is a bad compromise, just as “one size fits all” cycle helmets rarely satisfy anyone, resulting in a loose fit or pressure points as the adjustment system cannot accommodate such a wide range of heads.

Each individual size of bicycle helmet has further adjustment using a ratcheting, radial harness system to really fine-tune the sizing; a medium cycle helmet will usually adjust from 55cm-59cm, as well as offering 3 volume settings using a rear vertical adjuster.

In addition to sizing options for VR headsets, different style of headset harnesses could attach to the same headset base to accommodate users with different shaped heads, especially to suit the occipital bone (the pointy ridge at the back of your head).

An additional design solution is to offer a user-specific, custom facial interface (face cushion). A custom facial interface helps accommodate the asymmetry that is found in our faces, and the direct influence this has on the optical presentation when wearing a headset, and user comfort.

Current headsets are designed so that the face is centred within the headset, and the IPD adjustment works off this premise so that an IPD set at 64mm has equal spacing of 32mm left and 32mm right.

But what happens when your face is not centred within the headset because of your facial asymmetry, and your left eye is actually further from your nose (34mm) than your right eye (30mm)?

Take an image of your face, and draw a vertical line straight down the centre, then measure the position (width) of each eye relative to this centre. Repeat the exercise by drawing a horizontal line across your face, and measure the position (height) of each eye relative to this line, the results are often surprising.

Further analysis shows variations between the depth of each eye within its socket (orbit), the volume of the cheekbones (zygomatic or malar bone), the shape of the forehead (frontal bone) around the brows and reports of 19 different nose shapes.

We also see optical variations with eye dominance or eye-specific refractive errors requiring specific adjustments (it’s not ideal to wear glasses inside a headset).

These physical variations can be accommodated by a custom face cushion, whilst optical variations can be catered for fitted prescription lenses and automatic IPD adjustment using eye tracking systems to cater for each eye individually. We are starting to see new prototype headsets coming to market with these automatic optical adjustments, which is very encouraging.

virtual reality headsets ergonomics
Hacking the Vive to customize it to the user’s face shape

Currently the aftermarket face cushions you can purchase for headsets like the Rift and Vive are offered in different thicknesses and types of material, but follow the same concept of the OE (original equipment) face cushions of a symmetrical shape, equally spaced for left and right.

These don’t allow any asymmetrical accommodation, which means one side may be more comfortable than the other, this is seen in “witness marks” as the bony facial structures compress the padding used in the cushion. What is required is a method of supplying a face cushion which properly fits that individual’s face, and ensures they align correctly with the optical display.

One solution is the emerging technology of 3D face scanning, for example, the Bellus3D Face Camera Pro which is plugged into an Android smartphone. This combines 2 proprietary state-of-the-art technologies that measure 500,000 3D points on the subject’s face creating a very accurate high-resolution face model in seconds.

We could take this face model and integrate it with a design model of the headset to generate a data file for a custom face cushion base. This could be 3D printed and layered with self-wicking, antibacterial materials to provide a skin-sensitive layer to prevent any irritation, reducing facial stress and heat build up. A layered approach with breathable memory foam  could ensure a supremely comfortable fit!

The same technology can also be used to scan the head to assist in selecting the correct size of the headset and correct style of headset harness to suit the head shape. Once installed in the headset, the custom face cushion and correct headset harness will give the user a truly customized fit addressing their craniofacial asymmetries, whilst eye tracking systems adjust IPD for asymmetry and depth focus on a per eye basis.

As described in my fictional story at the start of this article, in the near future we could see virtual reality and augmented reality headsets offering an individually customized fit that we believe is required to truly get the best from the experience.

virtual reality headsets ergonomics
A customized face cushion is a solution to improve the comfort of every VR user

VR enthusiasts often focus on technical specifications, obsessing over resolution, pixels-per-degree, refresh rates, tracking systems…perhaps forgetting the most important element of the equation is the human interface. As one colleague commented last year, the clue is in the name “headset”, a “set” you wear on your head.

As consumers, we can purchase custom footbeds for running and cycling shoes and heat molded ski boots, which have been successfully sold through retail outlets for a number of years. With some forward thinking this business model can be incorporated into headset sales, with consumers only needing a “one-time” capture which could be applied to whichever headset brand they purchase in the future, similar to the data your optician holds on your prescription.

We should look forward to the immense benefits to be gained from customizing our immersive computing headsets, to provide the best comfort and optimum optical presentation so we can relax in our virtual worlds, at least until its time for a bathroom break!

virtual reality headsets ergonomics
virtual reality headsets ergonomics
How the VR headset of the future should be to have great ergonomics

I really want to thank Rob for this very interesting post. I agree with him that now maybe it is a bit too early for VR companies to care about this since they are mostly focused in actually selling the devices… because the user base is still quite little. But later on, in the future, I think that it is room for these important improvements in ergonomics so that the user experience inside VR can be optimal. People that spend lots of hours in VR will be happy because of this.

Tony @ Skarredghost