An Open Valve: How a Modding Community Shaped the Future of Virtual Reality

3D Printing & Imaging Digital Fabrication Fun & Games Home
An Open Valve: How a Modding Community Shaped the Future of Virtual Reality
Read articles from the magazine right here on Make:. Don’t have a subscription yet? Get one today. On the cover: NASA’s JPL is using VR tech to create the next Mars rover. Illustration by Viktor Koen.

In a private room, deep within the walls of one of the most respected game studios in the world, I stand before a veritable smorgasbord of electronics prototypes. These are the primordial building blocks that have evolved into what we call modern-day virtual reality. I scan the assortment, letting my eyes find their own path through the wires, LEDs, motors, displays, and 3D printed shapes. One catches my attention; I can’t seem to identify its purpose.

“This is the zombie machine, we put it on people’s heads to turn them into zombies we can remotely control.”

I’m tempted to laugh. I look at the device, a head strap with several 9-volt batteries attached, a circuit cobbled together on protoboard, and a couple stick-on electrodes. Then I realize Alan Yates, virtual reality engineer for Valve Software, is not joking.


Valve, a game company famous for titles like Half Life, Portal, Team Fortress, and Dota (and possibly more famous for the sequels of each of those) has a very tight relationship with makers. Valve owes its incredible success to those who, in the early days of computer gaming would modify and contort games to their liking, affectionately called “modding.” Instead of gasping and running scared from these adjustments, revisions, and bizarre twists of their product, the company embraced the community and it has served them very well. They’re valued at several billion dollars and their employees are the envy of anyone in the field. The games are so popular that there are entire ecosystems within them where players can develop custom, virtual items and sell them for real money, sometimes earning enough to supplant their day jobs.

I was visiting the Bellevue, Washington headquarters to see how this traditional gaming software company ended up as the creator of arguably the most cutting-edge VR hardware on the market, the HTC Vive. Yates, my tour guide, didn’t disappoint.


I pick up a device that looks like some kind of optician’s torture tool, a set of lenses lined up to the bright and shiny end of a dismantled pico laser projector. Yates explains that initially, the company was thinking that augmented reality deserved some research as a possible direction to go in hardware design. This prototype was an exploration in that path, but not one that was pursued any further.

“Ultimately,” he tells me, “what we found was that virtual reality was an easier problem to tackle right now.”

The distinction between augmented reality and virtual reality is a blurry one; both are immersive, virtual, and augmenting our surroundings. The main difference is that with virtual reality, the headset completely obscures your vision as opposed to showing an overlay on your actual viewpoint.

It was this direction that led to what we now know as the HTC Vive, a display that sits on your head like a pair of ski goggles, simultaneously tracking your head movement in 3D space and placing you into the virtual world it displays before your eyes. This unit stands apart from the others in that it also includes two controllers that allow the system to track your hand position similarly with incredible accuracy.


In the Beginning, There Was Nausea

In 2012 the team began collecting old headsets and dug up old research. What they found was not inspiring. Anyone who had a chance to try the VR of the ‘90s will be quick to admit that it wasn’t ideal. The poor performance of the machines meant that your experience was laggy, poorly rendered, and more often than not, nausea-inducing.

“We actually experimented for about two years acclimating people to virtual reality, attempting to get around nausea,” Yates says.


There were tons of tests and different angles approached to tackle the problem of the queasiness that occurs when your inner ears and your eyes aren’t detecting the same motion. The “zombie machine,” a galvanic vestibular stimulation prototype, is one example of this. The device uses electrical pulses to stimulate your inner ear to make you actually feel motion. By stimulating one side while someone is walking, they’ll naturally turn that direction. By triggering this stimulation remotely, you can crudely control a person like a radio- controlled car, or make them into a zombie as Yates puts it. Luckily, the zombie machine didn’t make it into the final product.

The magic formula to stop nausea ended up being a mixture of several things all working fluidly together. The physical display needed to be able to update at incredible speeds to keep your eyes from noticing any delay, and the tracking of your movements needed to be extremely accurate. Any little movement had to be translated through the system and to your eyes before you could perceive a change.

“Finally… the conversation could move on from motion sickness,” says Yates’ teammate Christen Coomer.

Fabricating prototypes

In the initial shift away from fiducial markers, the headset was tracked with a camera.
For a more exhaustive look at all the prototypes that lead up to the Vive HTC, check out our exclusive overview.

Once Valve settled on a tracking technology and a display system, things began to go incredibly fast. Modern desktop fabrication tools allowed the team to try new ideas very quickly. Many of the early prototypes looked like things that someone could make at home, and Yates agreed, this tech isn’t out of the reach of an enthusiast.

“3D printing is core to our ability to do this,” says Yates. “I don’t know how we could have done all of this without it. We have 3D printers, laser cutters, and a PCB mill. Those are really the three fundamental tools you’d find in a makerspace and that’s really all you would need to do most of this.”

Valve’s background was in software, where you can make an update or “patch” and distribute it within hours. Rapid prototyping allowed them to carry this methodology over into hardware. The engineers could create a prototype and get feedback from their peers in the morning, and have a revised physical item fresh out of the 3D printer in the afternoon. Previously, something like this would involve weeks of waiting while a prototype was constructed elsewhere, then delivered.


During this type of process, there are happy accidents that take on a life of their own. You can be developing one experience and every tester steps inside and does the same unplanned action, but they all love it. That unplanned feedback ends up being the direction you should go. This is true in both hardware and software experiences. If everyone picks up a controller the same “wrong” way, it is your design that is wrong and should be adjusted.

Sharing is integral, Coomer explains. “If you’re doing something privately, you’re not learning,” he says. And what the team learned is that in virtual reality there were no hard rules. “Everything we thought we knew was out the window.”

Valve continued refining the design drastically even a few weeks before the commercial release of the VR headset. The team didn’t have an established road map, so trying new ideas was their primary method of determining what worked and what didn’t. They’d push out prototypes to coworkers to get feedback as early and often as possible, and cancel those that didn’t pan out — they realized there was no point refining and polishing a prototype that they were not going to pursue.

Since Valve was built on the makers who modded games, the team is eager to see how people mod the HTC Vive hardware. The device had only been out on the market for a few weeks and yet people were already customizing and altering them. One person replaced the elastic straps with the head harness from a welding mask, allowing for easier transition from wearing to not wearing the goggles. One team of developers used a tracked controller mounted to a camera to overlay the game environment onto footage of a person playing it, allowing someone to watch a video and see the player immersed into the game world. These were unexpected modifications, and welcomed completely by the company.



Recruiting at Maker Faire

How does a person end up as a virtual reality engineer at Valve? The short answer is to get out there and make stuff. Valve has been very open with their hiring practices. Their employee handbook, riddled with humor and great illustrations, is open to the public. The most striking illustration in that handbook is the description of the ideal employee. They call it the “T-shaped” employee — someone who has a single area of specialty, but a very broad range of general knowledge. This is necessary, as you really need to be flexible and able to react to feedback, constantly pivoting toward a better product.

Maker Faire, as it turns out, is a perfect place to find these people. Of the handful of virtual reality engineers I spoke with during my office tour, at least three told stories of being approached by Valve while running a booth at Maker Faire.

When asked about the engineering degrees and education often required by positions in R&D, Yates explained that having someone with a self-taught and diverse background is actually an asset. He and the teammates contend that when someone has spent years approaching problems the “typical” way, they tend to become locked into a way of thinking, and to use standard methods to solve problems. When someone has a more diverse background, they may be missing some specific knowledge, but they often approach each problem with a unique perspective that can result in some unexpected outcomes. They may solve problems in ways that a traditionally trained professional never would have considered, or worse, discarded as “not the way it is done.”

The Big Launch

For shipping a hardware product of this scale, Valve partnered with Taiwan-based HTC. They talked with several manufacturers but liked the good reputation HTC had with their hardware construction, bringing years of experience to the table to help ensure a smooth launch.

One crazy aspect about the launch is that most developers didn’t have final hardware, not because of some secretive plan to keep it under wraps, but because the hardware was being refined all the way up to the very last possible seconds.

The official launch date for the HTC Vive was April 5 of this year. My visit was on May 2. Every person I spoke to within the company was still giddy with the excitement of units being shipped to the public.

The Vive and the competing Oculus Rift VR headset that launched on March 28 are the two major players in the high-end virtual reality device arena. Both are just getting started and will soon have to contend with Sony’s PlayStation VR, slated to arrive this October.

The future of VR at Valve

What accessories Valve is working on next are a mystery. I asked, prodded, and begged for a hint no matter how subtle, about the next toys I could hope to see. Images of body suits ripped from the sets of science fiction TV shows flashed in my mind. The only answer they would divulge is that their R&D has not stopped or slowed. The giant grins seen across every member of the team told me that whatever they’re working on, it’s cool.

“The eyes and hands were kind of the minimum level of tracking we had to achieve for a product,” Yates says. “Supplying feedback for the rest of the body is much more complex, and probably the next 10 years of research.”

Virtual reality is in its infancy right now. The devices that were laid out in front of me ranged from cobbled together to completely refined, and yet this is the absolute beginning. These are the Atari days of virtual reality, a time when the technology is fresh in people’s homes. A time we’ll look back on, and joke about how arcane our methods seemed. I can’t wait to find out what kind of cool things we’ll be playing with when we make those jokes.

Hopefully, they won’t be zombie machines.

Discuss this article with the rest of the community on our Discord server!

I get ridiculously excited seeing people make things. I just want to revel in the creativity I see in makers. My favorite thing in the world is sharing a maker's story. find me at

View more articles by Caleb Kraft