Both the Rift and the Vive first launched to consumers around this time two years ago, but their debut, and the games that launched alongside them, were the culmination of years of prior game design experimentation in a new medium that brought both new opportunities and challenges. Cloudhead Games, developers of Vive launch title The Gallery: Call of the Starseed, were among those leading the charge. On this occasion, the two year anniversary of modern VR headsets becoming available to consumers, the studio’s Lead Programmer, Paul White, and Narrative Designer, Antony Stevens, look back at the studio’s journey in VR development and where it has led them today.
The First Climb
Fall 2013, Oculus DK1 + Razer Hydra
My journey into VR locomotion began with the sunsetting Razer Hydra in late 2013. An early motion controller system tracked by a low-power magnetic field, the Hydra was originally designed as a peripheral for flat PC gaming. But for some of us, it was also an unlikely hero—the Hydra was the first big key to unlocking presence in virtual reality, thanks to its positional tracking
It was the era of the DK1, the first of the Oculus Rift prototypes available to Kickstarters, offering only rotational head tracking during its initial foray into the rebirth of VR. Without positional tracking of the head or hands, player movement in VR projects was either bound to the analogue sticks or omitted entirely. These were the standards and limitations of the time; VR as we know it today was yet to exist.
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Image courtesy Cloudhead Games
I was working on Exploration School, an early tech demo for our built-for-VR adventure game The Gallery (2016). My challenge was to use the Hydra to mimic the motions of climbing a wall without using control sticks—just reach out and grab it. It sounds straightforward now, but during those early days of VR we thought it could never be done with the available tech.
Holding the wired Hydra, you would reach out with your hand and press a button to capture the position of that arm on a surface. Any motion you made next would be countered and represented in game with our body persistence. If you let your arm down, your position would counter that movement, causing your camera and in-game body to move upward. If you raised your arm up, your position would counter, and you would climb down. It felt intuitive, all tech considered.
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With that inferred root, we then had the approximate location of the player’s torso in relation to their head, and could then adjust their body avatar with movements accordingly. We could tell the difference between natural displacements, from the player crouching into a tent, to peering over a balcony at the distant world around them.
In the end, the feature never made it in. Everything was about to change anyway.
The Great Divide: Comfort and Realism
Summer 2014, Oculus DK2 + Razer Hydra
VR dev kits were being released to the public in droves, now with positional tracking, and people were getting motion sick. Just by putting on a headset, it became an immediate uphill battle for comfort. Using your hands and body, standing up and crouching down—it had all added so much to presence. But it had come at a cost. Any time the camera moved without the player, it was barf city. And in an exploration game like The Gallery, you couldn’t just explore the contents of your chair.
Most locomotion in VR was now split between ‘Body Cart’, ‘Tank Move’, and ‘Stick Move’ with yaw rotation. The latter was the worst of the bunch, not only producing artificial forward-backward movement (vection), but also allowing the player to control the camera independent of their head position. Instead of the Body Cart, your face was the one along for the ride. If motion sickness was going to be the widespread problem it was trending to be, we would need to find a better way.
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Image courtesy Cloudhead Games
In any given moment, the human eye is capable of what’s called a ‘saccadic movement.’ Your eyes are constantly dancing, looking around for other things, even though to you it seems like the movements are smooth or even still. It’s an imperceptible movement—a jump. This was the basis for VR ‘Comfort Mode’.
Rather than continuously rotating the camera over a duration, as yaw rotations do, Comfort Turns are instantaneous. You press a button, or flick the control stick, and the player camera changes its facing direction. And because it’s instantaneous, there’s no visual motion for your brain to perceive, and no physical movement for your inner ear to detect—no vestibular disconnect. It goes a long way to mitigating motion sickness, and the option has remained a standard for comfort even in today’s evolved VR experiences.
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Designing an Experience
Spring 2015, SteamVR + HTC Vive (Developer Edition)
After GDC, people loved roomscale; it was a new feeling for everyone. But we still had a game to build. Whatever we made for roomscale had to play into the full-scale levels we had been designing for The Gallery up to that point.
The new freedoms of positional tracking, artificial locomotion, and variable heights all at once were almost too much. They contradicted the core feeling and pacing of the experience we’d designed. We needed constraints. And a new type of comfort.
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Image courtesy Cloudhead Games
We experimented with rapid locomotion prototypes to see what landed. The goal was to align our locomotion with how we wanted the player to perceive the game. More advanced techniques felt superfluous and worked against the tone and feel of our slow-burn exploration. We were also a small team of seven and we had to consider player-fatigue—something we had no metrics on.
How long could players explore inside VR before they felt eye strain or exhaustion? How much mental load, between advanced controls and puzzles, could a player bother with on top of that? And that was yet to even consider nausea.
Instead of being limited to sitting or standing in one position like with the Hydra or DK2, SteamVR had its own issues: Players were literally running into walls. We needed to find a way to redirect players to the center of their physical space, so they had the maximum area to work, play, and explore. Like with the GDC Elevator Demo, we didn’t want the player to feel like they were constrained to just their room.
Artificial locomotion—traditional gamepad movement—was the jumping point. We experimented with play bounds (the ostensible walls of the virtual roomscale volume) overlaying as a grid when the player moved forward with the analogue stick. Then we simulated head bobbing like in a traditional FPS.
Our ‘Body Joystick’ approach had you at the center of your room, with any offset direction and distance from that position representing the directional vector and velocity of your movement—you used your body as the controller. ‘Arm Joystick’ used the motion controller itself like a flight stick (a similar method is known today as ‘Onward-style movement’).
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All of these methods worked against the feeling of our experience. And all of them made you feel like you were going to fall over. If you accelerated instantly, you’d get a lurching in your stomach. If you accelerated gradually, you’d get a different lurching in your stomach.
At the time, the few metrics we did have indicated that artificial locomotion wasn’t working for players. Now, with roomscale, it wasn’t working for our game either.
Blink and You’re There
Summer 2015, SteamVR + HTC Vive (Developer Edition)
One of the first forms of teleportation I worked on was ‘Astral Navigation’. You would look up in-game and see a star path between the clouds that represented the layout of the level you were in. Aim to where you wanted to go and, when you looked back down, you’d have teleported to that point in the scene. Impractical, but we were trying to explore the upper limits of what we could do with movement.
At this point, Valve put out an early photogrammetry scan of their office (a rough point-cloud version similar to the current SteamVR Environment below). In it were various ‘information’ nodes that you could teleport between to navigate the room. Rather than use artificial locomotion to slide around, you could zip from node to node. We instantly liked it—it felt cool, and it didn’t make you sick.
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When the first episode of The Gallery finished and public adoption of VR finally arrived in April 2016, the take on Blink was increasingly polarized. Teleportation had become the standard, but the rotational and persistent bounds features we added with Blink felt too insular. Valve had made simultaneous developments to their teleportation, and player preference leaned toward those minimalist, built-in systems. We had inadvertently invented many of the same wheels and our systems ultimately overlapped.
When the Oculus Touch controllers released in December 2016, we updated Blink to be more in-line with the standards of the time. Rather than aiming with your head (literally looking to where you wanted to go) as we originally had it, we set the default to cast from the hand, so you could point to your destination instead. We also added a ballistics trajectory arc that felt more intuitive to our players, albeit less connected to our world.
The feeling mattered, but so did the options.
Free Locomotion
Winter 2016, Oculus Rift CV1 + Oculus Touch
Artificial locomotion was taking on a new name: ‘Free Locomotion’. Onward—a tactical FPS fully-integrated with smooth, artificial locomotion—had become a cult hit with VR gamers. Some players felt that Free Locomotion was now the only way they could feel truly immersed. There was an outcry from the community any time a game lacked the option, and we would ultimately add support in the second episode of The Gallery, despite it being built for our default option, Blink.
Also gaining traction at the time was ArmSwinger. What I immediately liked about the ArmSwinger demo I saw was that the controllers inferred the player’s body direction by the motions they performed. You could turn the body with the direction of the arms, and still allow the head to pan decoupled from that direction. The downside to ArmSwinger however, was that it still used up a button and didn’t ultimately address vection issues.
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I could then set the exact threshold of when movement should start; two periods that are cached or buffered can tell me when a player is running in spot based on their arm frequencies. With this method, you could swing one arm and pick an object up with the other while still continuing to move.
With body pucks (such as the Vive Tracker) not yet available to the public, full-body persistence would require us to infer the root position of the player. Once there, however, you could use height and leg data to start tailoring leg strength coefficient and calculating the specific physics and kinematics of any single person. Players could run at the same frequency beside each other, yet still have different travel distances.
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But that great divide between comfort and realism is still going strong, and it becomes increasingly challenging as we fight to increase VR adoption. Current VR owners are desperate for realism and freedom, while the non-owners will never be sold unless they’re comfortable.
Teleportation can allow developers to know and design where the player is able to access and see at all times, but it can also feel limiting to the player—like digital training wheels.
Free locomotion can allow players a boundless experience, but it typically requires an acclimation period. Some people simply can’t handle it, and others don’t find it entirely immersive.
Implementing one method into a game that was built for the other can break the balance, or sometimes the entire experience.
Simply, there are sensibilities in designing locomotion for VR. We, as developers, want to push the boundaries of immersion, but we should also strive to maintain a comfortable and considered experience for all players.
In the future, we want to release a ‘Mutant Locomotion’ scheme, a culmination of all our various methods with no compromises. On the right hand you can Blink, with Comfort Turn inputs on either hemisphere of the analogue stick or touch pad. On the left hand is free locomotion. Buttonless Arm Swinger heuristics are ongoing and always sensing for oscillations to occur. We want to put it all on the table and really know how players want to explore. One distilled option, one integrated experience.
That’s the important bit: give players those options, but remember to tailor the locomotion to the experience you want to create. There are too many independent developments out there attempting the shotgun approach with 50 different locomotion schemes. The options are good, but no game could be specifically designed with all of them in mind. At the end of the day, ask yourself what you want your player to experience. Take the lessons learned, the methods you’ve enjoyed, and listen to the feedback from your users. Ultimately, those are the people who are playing your experience at great lengths, and can let you know what they enjoy about it and what they don’t.
The next step is when we have additional tracking points in the mainstream, or perhaps galvanic stimulation of the inner ear. Then we can get into the snowboarding and the skateboarding and the hoverboarding. It opens up a huge new window for experimentation in locomotion.
And honestly, I like that stuff—it’s what made those early days so exciting. We have a game to make and things to do, but in the end it’s still about pushing boundaries together. There’s a huge risk in pouring time and money into experimentation in VR, and a lone developer can’t climb to the finish and fully realize it themselves; it takes a village to move a medium.
One day, through a collective effort, we’ll find a better way, something far beyond the standard motion and teleportation. The walls will open on all sides to reveal a skyline with infinite possibilities and directions to explore.
Source: Road To VR