VR Locomotion Is A Problem That Has Many Half-Solutions
Locomotion is one of the most glaring problems plaguing developers who work on VR games. In traditional video games, movement mechanics are pretty much locked down: You either have a keyboard and mouse or a gamepad. In the case of the former, you’ll use the arrow keys or the WASD keys to move forward and aft and strafe from side to side. In modern games, you make use of the mouse for aiming, targeting, or navigating menu items. Gamepads come with consoles, so developers always have a standard control scheme to work with that doesn’t change much from game to game.
You won’t find many VR-supported games that use keyboard and mouse configurations, but there are many VR games that take advantage of traditional gamepads. There’s nothing stopping developers from supporting the classic two-thumbstick artificial locomotion method that almost every first-person console game relies on, and in fact, some games do support that method. For example, Adr1ft offers the traditional control method, but that game is also playable on a 2D screen. Had the developer built the game for VR only, it may have chosen a different locomotion method. Most built-for-VR games shy away from linear lateral movement to maximize the audience that is comfortable playing it.
In VR, the concept of standard locomotion controls is turned on its head. Most of the time, traditional game controls don’t work well in virtual reality games. Lateral movement with a thumbstick or a keyboard can trigger motion sickness in a lot of people. Your inner ear controls your sense of balance and spatial awareness (vestibular system), if what your inner ear perceives is different from what your eyes perceive (vestibular mismatch) you can lose your balance or get dizzy. A vestibular mismatch can even trigger nausea or vomiting in extreme cases.
Vestibular mismatch problems became apparent in the early days of Oculus VR development. VR developers quickly discovered what triggers motion sickness, and several devs started working on solutions for the problem. So far, we’ve encountered no less than a half-dozen different locomotion mechanics. None of them are perfect, but each one has its merits. If nothing else, the variety of options illustrates the ingenuity of the VR developer community.
First-Person VR Locomotion Methods
Comfort Mode
Cloudhead Games designed one of the first VR locomotion systems that address the lateral motion issue. Early in the development of The Gallery: Call of the Starseed, Cloudhead Games found that linear motion with a joystick triggers sickness in some people, but short incremental adjustments don’t. The developer created a system called Comfort Mode that splits your rotation into short, instantaneous jumps instead of a continuous spin, which is surprisingly effective. For whatever reason, your brain accepts that your surroundings change in the blink of an eye, but it can’t reason with spinning scenery when you’re stationary.
Comfort Mode is one of the most successful options for seated locomotion. Many developers implemented the feature, or a variation of it, to their VR games.
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Teleportation
Comfort Mode isn’t the only mechanic that Cloudhead Games pioneered. The developer also created the Blink system, which is widely used for standing and room-scale VR games. Blink allows you to teleport across the map so you don’t have to rely on artificial forward movement. It also lets you pinpoint an area within view that you’d like to move to and jump to it instantly. With Blink, you can also spin around to any angle.
When you activate Blink, you’ll see a round marker with an arrow on it. The arrow indicates the direction you’ll be facing when you move to that position. Sliding your thumb over the thumbpad allows you to change the direction you’d like to face, which helps when you're navigating cramped spaces.
Cloudhead Games developed the Blink system to address the limited play space of VR games, and many developers have taken advantage of the concept. Nearly all first-person VR games that require navigation through a map offer a Blink-like option.
Warp Speed
Blink isn’t the only teleport mechanic that you’ll find in VR games, though. CloudGate Studio, the developer behind the dinosaur hunting game Island 359, took the Blink concept and tweaked it to suit its game. CloudGate wanted to maintain the senses of dread and terror that fighting off dinosaurs face to face trigger, so it didn’t like the idea of instant teleportation. Instead of teleporting, CloudGate’s system is sort of like an adrenaline rush where you become hyper-vigilant and sprint to safety.
CloudGate also incorporated a stamina bar to its variation of Blink. The further you move in one burst, the more stamina you burn, and you must briefly rest to recover if you fully deplete your stamina bar.
Neat Corporation came up with a clever mechanic for its upcoming VR stealth game Budget Cuts. The developer incorporated a visual preview system for its teleportation mechanic that allows you to navigate through the environment without being detected. You can place a marker where you wish to move that gives you a live video feed of that space in a bubble in front of you. If the coast is clear, you can move forward.
Valve uses a bubble teleport system in The Lab to switch between games, but it doesn't give you a preview of where you're going. In the lobby, you’ll find bubbles at each station. To enter a mini-game, pick up the bubble and place it over your head. To exit a mini-game and return to the lobby, press a button on the controller to spawn a return bubble and stick it over your face.
How to use the bubble mechanic isn’t immediately apparent, but once you know what to do, the system is surprisingly intuitive.
From Host To Host
Damaged Core from High Voltage Software features a unique locomotion system—if you can call it that. Instead of figuring out how to move around comfortably, High Voltage Software decided to avoid movement altogether.
Damaged Core features a parasitic teleportation system. In the game, you play a parasitic energy that can take control of host robot bodies. You never move around as a host robot, but you jump across the map by switching from host to host. As one body wears out, you grab hold of a new one and continue the fight.
Not Everyone Likes Teleporting
Teleportation is undeniably one of the most comfortable VR locomotion solutions around, but it’s not for everyone, and it’s certainly not suitable for every type of game. Being able to move great distances in the blink of an eye feels like a cheat to some people. Admittedly, it’s not the best solution for competitive gameplay.
Trackpad-based artificial locomotion appears to be the solution of choice for first person shooter fans. Onward, a team-based competitive first-person military simulation game from Downpour Interactive, uses trackpad navigation, and it’s one of the most popular titles available for the Vive.
Trackpad-based artificial locomotion is like thumbstick-based artificial locomotion, but it’s not quite as jarring because it doesn’t take rotation control away from you. To move around in Onward, you press down on the touchpad. Where you press on the trackpad dictates the direction you walk. Movement is decoupled from the direction your head and hands are pointing, so you can look around and target enemies as you run across the map.
Still, trackpad-based artificial locomotion isn’t the most comfortable option, so we wouldn’t recommend it for a first-time experience. Even without rotation, forward movement when you’re not actually physically moving can trigger a vertigo-like sensation.
Swing Those Arms
The last locomotion option that we know of is called ArmSwinger. As the name suggests, to move around with ArmSwinger locomotion, you swing your arms back and forth. ArmSwinger is triggered by the grip buttons on each controller. Squeeze the grips and swing your arms at your sides as if you were walking at a brisk pace to move. The faster you swing the controllers, the faster you move in the virtual world.
ArmSwinger locomotion is available to developers, but we haven’t seen any games that use this system yet. Climbey uses a similar locomotion system for jumping, though. To jump in Climbey, you must swing both your arms at your side in unison to “push off.” The harder you swing, the higher you jump.
More To Come
Developers already have many choices for VR locomotion. Each option helps solve different problems and applies to various styles of games. However, none of the available options are suitable for the long run. Someone new must come up with an approach that satisfies a wider range of needs and consumer desires.
Or maybe it won’t be a newcomer. Denny Unger was recently a guest on The Voices of VR Podcast, where he revealed that Cloudhead Games is working on yet another VR locomotion solution for the second installment of The Gallery. Unger didn’t go into details, but he said his company would start talking about its new method before the launch of Episode 2: Heart of the Emberstone, which is due in the first quarter of 2017.
Kevin Carbotte is a contributing writer for Tom's Hardware who primarily covers VR and AR hardware. He has been writing for us for more than four years.