Motion sickness actually encountered this problem a decade ago during the 3D game revolution: Why do some people experience dizziness and nausea when playing first-person 3D games?
The reason lies in the “vestibular visual misalignment“.
For example, the following VR game
I am strapped to a skateboard and accelerating downward.
The picture your visual system feels is like this——
Instead, the vestibular system felt like I was sitting still in the chair.：
Simply put, your eyes tell your brain you’re moving, your body tells it you’re not 。。。。。。 , the brain is confused, and then there is no more then. We won’t expand in detail on the specific motion sickness, after all, our topic is not about why humans get seasick and carsick.
So, what does VR have to do to keep people from getting dizzy?
1、Because of the “vestibular and visual consistency” requirement, we have the same requirement for VR: “The IMU on VR and what is displayed on the screen should also be consistent.” So there is what you often hear: keep low latency (within 20ms) tracking, 60 fps, 90 fps, 120 fps without frame drops …… Once the user enters the VR should always keep the head tracking, even if the scene switching, content pause, but also must be directed to track, with a variety of devices to maintain the consistency of the body-eye brain. If you are using a cheap cell phone for computing, computing performance a can not keep up, rather than become black, not to drop the frame, card frame. Even so to now external technology can not perfectly solve the problem of vestibular and visual consistency, and currently can not do.
2、There is also the severing of the connection between the vestibule and vision, shielding one side. The way to block vision is simple, you close your eyes. Of course, if you block vision, is it still virtual reality? So, you ask, what about shielding the vestibular system? Yes, blocking the vestibular system is the only way to lift the VR motion sickness spell (visual and vestibular coupling), which I call “decoupling.” Decoupling’ can’t be cutting off the vestibular and visual systems, then you’ll even take a step and fall half to death, unable to keep your balance. Decoupling’ is blocking or weakening the vestibular system, for example, by taking medication, by taking vertigo medication.
With that said, there are many issues that can cause you to experience vertigo, including the low frame rate of your monitor, lag, acceleration, the painting style of the game, the complexity of textures, lighting and darkness, and more. One of the most influential factors is how the player moves, which is why we discuss spatial positioning techniques for VR in Chapter 1. Here we will analyze the various ways to move in VR.
1、 Handle movement
The use of a joystick to control movement, which is the same as traditional movement on the PC, is easy for players to understand, but the vertigo associated with this type of movement is severe. The game allows players to adjust the direction without actually turning their heads, and the game’s crouching action can be achieved by simply pressing a button, all of which induces discomfort in players. Even long-time VR players can not last more than 15 minutes, especially when approaching the wall, will feel the brain swelling pain, it is not recommended to use this approach in the game.
2、 Teleportation
Currently VR on the use of this type of movement more, such as “disappearing kingdoms” and other RPG games almost all use this type of movement, the freedom of this movement is higher, the design of the process in the instantaneous screen darkening and reappearance can also effectively reduce the player’s sense of vertigo. However, this way of moving the player is unable to see their own movement process, just similar to switching the position of the camera, if the frequent movement process in the battle is easy to lose their way. Combined with Room Scale, in the battle using Room Scale small range of movement, in the adventure and exploration process using instantaneous movement, the combination of the two ways for the most popular VR games is also one of the best way.
3、Jump
《Sairento VR》 in the jumping action and the above-mentioned instantaneous way somewhat similar, but before moving the player can know the next trajectory in advance, the process of moving will also be displayed on the screen (not the screen darkened and then appear), the game also added a “bullet time” in the jumping process, encouraging players to use a variety of attacks in the process of moving, to produce the feeling of fighting while walking, so that the pace of the game is more tighter, but this type of movement also brings a stronger sense of dizziness.
4、 Carriers
Racing games are an enduring genre, how do racing games fare in VR? We said in the article above that if the game graphics and vestibular sensations conflict with each other to bring about vertigo, then racing games should be very vertiginous, right? The answer is no, the reason is that when playing racing games, the brain will help you cheat the vestibule, the player is active in the process of movement, active movement will effectively reduce the vertigo, that is why some people will be dizzy in other people’s cars, while they drive but not dizzy.
5、 Hand movements
The basic idea is to move with hand movements in a way that keeps the visual and physical senses as consistent as possible. For example, “The Climb” in the simulation of real rock climbing, “VINDICTA” in the player simulation of running action, throwing hands to achieve forward running. Oculus announced in October, OculusQuest should usher in the first pure hand tracking technology in 2020.
6、 Spatial positioning motion tracking system
The technology is detailed in Chapter 1 content VR knowledge popularization a: spatial positioning technology allows players to move within a certain range, so that players do not feel dizzy. However, for some games, this range is still too small and can only be used as an aid to movement or as an area to dodge, and needs to be combined with other movement methods.
7、 Virtuix Omni Virtual Reality Treadmill
VirtuixOmni The virtual reality treadmill goes one step further than Room Scale, allowing you to walk infinitely in a virtual world. However, since offline space is obviously limited, both in homes and experiential stores, there is a virtual reality treadmill designed – to make it feel like you are walking (both physically sensory and visually), but actually in place, as the Ready Player One movie has shown.
It is very difficult to make the effect of stepping in place to be fake and make users feel like they are really walking. At first you may think, isn’t the treadmill in the gym just running by stepping in place? But the treadmill there actually sets a speed at which the track rotates, and then the user keeps up with the rotation of the track at a corresponding running speed. If you want to make a VR treadmill, you need the track to know how the user is walking and then rotate at the correct speed to keep you in place, which is very difficult, and the treadmill in the gym is not multi-directional. Why is it difficult? The biggest problem with getting the machine to adapt to the human pace is latency. Because human walking is irregular, you don’t know what his next step will be, and the time and speed are unknown. Therefore, in order to achieve track rotation in line with the human walking pace, the user’s movement must be recognized in a very short period of time and then transmitted to the treadmill, and the track will rotate accordingly. Unfortunately, with current technology, this process still takes too long, and if it takes too long (i.e., a large delay), it is likely to fall over on the treadmill. A clever designer came up with a solution: put a “pot” under your feet and a wheel on the bottom of your shoe so that no matter how you walk, you will slide back into the “pot”. Walking on a treadmill is very different from walking on real ground. This “difference” is not bad, but it means you need to learn another way of walking. This type of walking is a bit like walking uphill when the soles of your shoes are too slippery, and as a result, you can’t walk how to walk without sliding down. But in general, VR treadmill is a good idea, but the price of close to 10,000 yuan makes many players discouraged.
8、 Zero Latency
ZeroLatency，It is one of the most sophisticated virtual reality game centers in the world, with a game mode in which six players wearing VR devices work together to complete game tasks in a 400-square-meter venue. The venue (similar to a factory) is 28 meters long, 14 meters wide, and the overhead frame is 2.5 meters high. A disc can be seen at each steel frame node of the venue, and the disc is arranged with 8 PS Eye cameras (Sony’s new generation of somatosensory device PS MOVE components), with an average of 10 cameras assigned within each 5*5 square meter steel frame, for a total of 129.
For spatial localization, Zero Latency uses the PS MOVE optical localization and image recognition solution.PS MOVE is based on the principle that different colored light spheres in the PS Eye camera can render a significantly different image from the background image, which is then combined with an aerial triangulation algorithm and a computer vision (CV) algorithm to extract real-world coordinates. However, the dark room effect can occur in the arena due to the strong interference of visible light. In addition, to make the environment simulation more realistic, they added some environmental simulation devices, such as fan system to simulate cross wind and elevated floor to simulate bridges, etc. The motion of VR can be divided into two categories: “self-motion” and “non-self-motion”. zero Latency’s approach is self-motion. Zero Latency gives the player the best experience, but the scale and the investment in equipment required here is not affordable for the average player.
Summary：
At this stage of VR, various means of movement have their own advantages and disadvantages, the player’s acceptance of vertigo is not the same, etc., in the end, which is more suitable for use? There is no definite conclusion, and even some games do not have a means of movement, like “Hero Sam”, “Career Simulator”, “Super Burn”, “Jida Chronicles of the chaotic frontier” (Jida Chronicles) and other games are used in a fixed position. And everyone’s VR vertigo level is different, the feeling of various ways of moving may also be different, VR games to play more body will slowly adapt to, the degree of vertigo will gradually reduce. If you also want to experience VR games and worry about the vertigo problem, you can start with some games that have a lower level of vertigo. Through the method of neural implantation, will the final VR be like the movie “The Matrix”? What do you think?
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