Limited freedom in VR
If you follow me on twitter you might already know that I work on a project called VRocketz. It's a VR game for oldschool 1on1 deathmatches. Now everyone following recent VR development might tell me that this is a bad idea. Talks and articles tell us developers to create games where the player stands up, turns around and interacts with the world in a limited space. Even room-scale VR is a pretty limited space.
Moving ingame while not moving with your body is bad and can make player sick. Yes, avoiding motion sickness is tricky, but I'll come back to that later. Those talks and articles I mentioned also say that it's important to give your play a wow-effect, make them overwhelmed by the VR-experience. Let your parents or grandparents try it and non-gamers in general. I agree that this is a good thing and all, but non-gamers are especially prone to motion sickness in my opinion, as many will even get confused with 3d movement with a gamepad an a TV-screen. So, we make sure that we use techniques like teleporting in VR to sidestep the whole movement problem and the sickness it can induce.
Teleporting in The Lab
Most Gamers don't want to physically move around
But I see a problem with the choice of audience here. It keeps reminding me of the Wii. It was a great console for introducing gaming to people who never cared about video games before. It was very affordable and gave the players a great experience with motion controls. You put energy in that tennis swing and you had fun doing it. Well, for a while. Fast forward a few weeks or even months and if you used your Wii you mostly sat on the couch and wiggled the wiimote around with your and, most motion came from the wrist. Also, there weren't many games for the so-called hardcore gamer and rightly so. Those guys and girls didn't find the idea of standing up and flailing around their limbs to play a game very appealing compared to sitting comfortably on their asses, controlling the game with their fingers and hands with a cleverly designed gamepad or maybe a keyboard/mouse setup.
Lazy Wii Guy
Why we need couch VR
Now, the Wii was rather affordable and that made it a great success. Nearly everyone could go out and buy one. Not so VR. Right now it is a big investment. You need a beast of a computing machine in your home. If you want VR you should aim for the outer rim of high-end hardware. Oh, and you also need to buy the VR hardware. How many Wiis could you buy with that money? Okay, but who will shell out that much money for gaming hardware? Well, hardcore gamers do. But, they probably won't be able to clear out enough space to wildly move around while playing VR games. No, we need couch-based VR experiences! Hardcore gamers don't want to play their online games spinning in front of their PC, maybe even falling over cables or bumping their knees. So, if these gamers are the early adopters of VR we should give them the games they know and love.
Games for Gamers
There are already games targeting that audience. All sorts of cockpit based games for example. Racing in cars and flying in air or space or piloting a submarine. Great games that can mostly sidestep motion induced sickness as the player has a cockpit which gives the player a clear reference of their position and movement. Then there will be other games that can use a Lucky's Tale or boardgame approach, so 2.5D jump and run games or RTS/MOBA games shouldn't be too hard to port into VR space.
Eve Valkyrie was made with VR in mind
But there is another genre that mostly caters to hardcore gamers, the first person shooter. But the mere thought gives any VR developer nightmares with all its strafing and turning and jumping and crouching.
Why VR and FPS is a dangerous combination
At the center of FPS controls is turning around, a lot and fast. This is traditionally done with a mouse or an analog stick.
John Carmack is certainly right, turning using the right analog stick (or any other input axis) will make you throw up sooner or later. But that only means that we need to find a way to turn in VR that works differently.
Reinventing turning around
Currently I have two approaches for that. First one is easy enough, make sharp 90 degrees turns using shoulder button input.
Quick turning using the shoulder buttons
It works and allows for fast navigation, but often enough you want to turn only a bit. How can we do a smooth analog turning without using an input axis and making the player sick?
Break the immersion!
Well, I do it like this. It feels a bit unintuitive at first, but works nicely. How? Well, I break the player's immersion. Don't lynch me just yet and remember that having to stop playing because you feel horrible breaks the immersion in a much worse way.
So, in detail, the approach is easy.
- Give the player a new environment of reference (this is the one that breaks immersion)
- Turn the enviroment by "dragging" it with your head
- Remove the new environment of reference (and letting the player back into his illusionary world)
Step One: Break the immersion
With the press and hold of the button I show a overdrawing cube with a grid around the player. The look reminds me of the holodeck and this was definitely my inspiration. This grid cube gives the player the illusion that he isn't really in the virtual world but that he's standing or sitting in a simulation room which is clearly visible.
Looking around in a temporary rotational reference "room"
Step Two: Turn the world with your head
At the same time the simulated world freezes in horizontal rotation and the player's head can adjust the world orientation relative to his body. Thereby he can rotate the world around himself. This feels pretty weird without showing him the simulation room because the player loses his rotational reference in the virtual reality. The simulation room acts as a new rotational reference but it is important to note that this room is just and illusion. To achieve this illusion the player, its camera and the grid cube is set up in a special way and rotated in synch with the head rotation. Because of that won't encounter any performance hit as we never start moving the world around the player instead the player rotates in the world as usual.
Dragging the world around the player
Step Three: Return to normal
The simulation room vanishes and head turning goes back to normal. The player returns to using the virtual world as rotational reference and the immersion increases again. The idea of the room probably fades from the player's mind already as he is walking or runnig through the virtual world filled with action that never stopped.
These two approaches work for me very well and while there is definitely a learning curve to the new rotational controls I never felt funny in my stomach.
You can either use these approaches or find your own. My point is that it is important to find solutions instead of sidestepping the problems. Find ways to prevent motion sickness without limiting free movement.