At VirZOOM we make exercise games that move you around in VR from your pedaling and leaning on a bike. Solving VR sickness has been our top goal, so anyone in a gym can step up and feel exhilarated by VR rather than the opposite. Sorry for the long post but hope to benefit other VR devs and show non-devs all that's involved.
Virtual reality is experienced through a headset which draws two images of the game, from the precise location of each of your eyes to create a stereo effect, in the direction your head is facing. VR has been around for a long time, but the release of the Oculus DK1 marked the first time it was performant enough for a mass audience.
VR before Oculus was released could cause sickness because of insufficient framerate to draw two wide-field images fast and sharp enough, and the latency of measuring your head direction and position. Since Oculus was released these have been solved by having more powerful computers, VR-optimized graphics drivers and rendering techniques, low-persistence LED screens, and better and faster sensors.
Quality VR requires updating and rendering two 100 degree images at least 60 fps, ideally 90 fps, on a screen that flashes its pixels quickly on/off at 1:3 ratio to not look blurry or flickery from the short distance to your eyeballs, with less than 15 ms of sensor latency combined with reprojection that mostly hides the game rendering time. And it has to account for lens distortion which is different for the red, green, and blue components of each pixel, and be antialiased because different jaggies between eyes will make you crazy.
This all takes up to 10x the horsepower of regular videogames, which are single image, usually 30 fps, and undistorted with a smaller FOV. This is why most VR games look a generation or two old. Fortunately GPU and engine makers have been hard at work optimizing drivers and techniques to leverage commonality between eyes and fact that you perceive the most resolution in the center of your field of view, to bring that multiplier down to 2-3x.
Even with the best hardware and rendering, VR can still cause sickness if games move your virtual head much differently from your real head. The difference between the acceleration your inner ears feel and the acceleration your eyes see is the cause of VR sickness. It turns out the pretty much every 3D game requires your virtual head to move around, which is why existing games have been astoundingly difficult to bring to VR.
From all our playtesting and feedback, we believe people have different levels of sensitivity which can trigger their simulation sickness, and they will only feel it 10 minutes after a game has crossed that threshold. Most people will incorrectly attribute their feeling to whatever they are doing at that moment rather than 10 minutes ago. This delay time is also why it's difficult for someone to "discover their limit" and "auto-tune" a game for it. It's true that repeated VR experience can acclimate users, but the amount and degree is again unpredictable, and a mass market product can't rely solely on that.
So games have to be redesigned with VR motion in mind. The most successful but also most limiting way to do this is "room-scale", whereby your virtual head moves the exact same way as your real head. In these games you are only allowed to play from a single location or in a little area, as far as the VR position tracking and your furniture allows.
One common way to allow you to move in virtual space is to put you in a "cockpit" where you can only see out windows. This approach evolved from the idea that you don't generally get sick playing 3D games on your home TV, because your brain can perceive your whole room which is not moving, and accepts that the TV portion is just an image. But that is also what makes this approach less good and immersive for VR. Because VR images aren't as wide as your real eye (100 vs 180 degrees), you have to draw the cockpit right in front of the user, and to the extent that its works make
We have a product that runs now on Rift, Vive, and PSVR and will soon on Daydream and upcoming mobile and Windows VR. Take my opinion for what it's worth.
Comfortable VR requires low-latency motion sensing, screen displays with pixels on/off for precise periods to avoid blur or flickering, simulation and rendering that is at least 60 fps, and asynchronous reprojection of that output to 90 or 120 hz. All of the above VR systems are capable of comfortable VR running applications that meet that framerate requirement. Many would additionally argue that head-position tracking is a requirement for comfortable VR, because otherwise the world "moves" with your head. We say it's definitely better to have than not, as long as it has the same low-latency as rotation sensing and is reliable.
Applications also need to minimize the difference between acceleration you see with your eyes and feel with your balance. Our research shows people have different trigger thresholds for simulation sickness, and different sensitivities to different types of acceleration (for instance most people can handle differences in forward acceleration than vertical, and both better than turning). Different applications have many ways to address this: low detail backgrounds or background occlusion when turning, "cockpits" that turn with you, shuttering of FOV to reduce peripheral detail when turning, teleporting, acceleration limits, head-synced turning, level design that encourages more or less accelerations and vertigo, room-scale only movement, etc. You will have to jump in yourself and find what you are capable of and what applications do the trick for you.
The rest comes down to features and ecosystem of each VR system. Hardware systems have been evolving very rapidly but here's a brief rundown.
Vive & Rift are very similar from sensing and screen and computing requirements,wide fields of view, high application framerates, They both now require a tether to your PC with I5-4590 & GTX 970 or better performance. Vive came out with full room-scale position sensing and two hand-controllers, which has led to a lot of great room-scale applications. Rift came out with built-in headphones which are key to enjoying the full VR experience, as sounds can be "binaurally" mixed to sound like they are coming from precise locations, and is lighter than Vive. There are a lot of Vive add-ons available now or soon that include face covers, wireless transmission, tracking pucks and alternate head mounts with headphones.
PSVR actually has a higher screen refresh (120 hz) than Vive & Rift (90 hz) which makes looking around (with async reprojection) feel more crisp. But most PSVR applications run at 60 fps rather than 90 fps like most Vive & Rift apps, which makes object animations and positional travel less crisp. PS4 Pro apps can hit 90 fps at about the same level of detail but that depends on the developer. The PSVR's screen might be the brighest and uses a different pixel technology, less little dots and more solid squares, that is a matter of taste. It's a little heavier than Vive but is balanced between front and back so the weight rests on your forehead--in fact its screen guard doesn't even touch your face like Vive & Rift, and can move out and in for easier use by glasses wearers. PSVR's position tracking relies on visible light which is a bit less robust than the other two, though all of them have problems in direct sunlight.
Microsoft VR is further out but looks to be aiming for PSVR level performance on PCs with less than Rift/Vive specs. A notable feature is "inside-out" position tracking, coming from their Hololens research, which doesn't require external cameras like Vive/Rift/PSVR.
Daydream on a Pixel phone (Snapdragon 821) is surprisingly good for mobile. In our tests it has about twice the power of S7 running on GearVR, which our application can't yet run on with sufficient detail. Its applications require 60 fps but it has asynchronous reprojection to what feels like a 90 hz screen refre
Slashdot Mirror
At VirZOOM we make exercise games that move you around in VR from your pedaling and leaning on a bike. Solving VR sickness has been our top goal, so anyone in a gym can step up and feel exhilarated by VR rather than the opposite. Sorry for the long post but hope to benefit other VR devs and show non-devs all that's involved.
Virtual reality is experienced through a headset which draws two images of the game, from the precise location of each of your eyes to create a stereo effect, in the direction your head is facing. VR has been around for a long time, but the release of the Oculus DK1 marked the first time it was performant enough for a mass audience.
VR before Oculus was released could cause sickness because of insufficient framerate to draw two wide-field images fast and sharp enough, and the latency of measuring your head direction and position. Since Oculus was released these have been solved by having more powerful computers, VR-optimized graphics drivers and rendering techniques, low-persistence LED screens, and better and faster sensors.
Quality VR requires updating and rendering two 100 degree images at least 60 fps, ideally 90 fps, on a screen that flashes its pixels quickly on/off at 1:3 ratio to not look blurry or flickery from the short distance to your eyeballs, with less than 15 ms of sensor latency combined with reprojection that mostly hides the game rendering time. And it has to account for lens distortion which is different for the red, green, and blue components of each pixel, and be antialiased because different jaggies between eyes will make you crazy.
This all takes up to 10x the horsepower of regular videogames, which are single image, usually 30 fps, and undistorted with a smaller FOV. This is why most VR games look a generation or two old. Fortunately GPU and engine makers have been hard at work optimizing drivers and techniques to leverage commonality between eyes and fact that you perceive the most resolution in the center of your field of view, to bring that multiplier down to 2-3x.
Even with the best hardware and rendering, VR can still cause sickness if games move your virtual head much differently from your real head. The difference between the acceleration your inner ears feel and the acceleration your eyes see is the cause of VR sickness. It turns out the pretty much every 3D game requires your virtual head to move around, which is why existing games have been astoundingly difficult to bring to VR.
From all our playtesting and feedback, we believe people have different levels of sensitivity which can trigger their simulation sickness, and they will only feel it 10 minutes after a game has crossed that threshold. Most people will incorrectly attribute their feeling to whatever they are doing at that moment rather than 10 minutes ago. This delay time is also why it's difficult for someone to "discover their limit" and "auto-tune" a game for it. It's true that repeated VR experience can acclimate users, but the amount and degree is again unpredictable, and a mass market product can't rely solely on that.
So games have to be redesigned with VR motion in mind. The most successful but also most limiting way to do this is "room-scale", whereby your virtual head moves the exact same way as your real head. In these games you are only allowed to play from a single location or in a little area, as far as the VR position tracking and your furniture allows.
One common way to allow you to move in virtual space is to put you in a "cockpit" where you can only see out windows. This approach evolved from the idea that you don't generally get sick playing 3D games on your home TV, because your brain can perceive your whole room which is not moving, and accepts that the TV portion is just an image. But that is also what makes this approach less good and immersive for VR. Because VR images aren't as wide as your real eye (100 vs 180 degrees), you have to draw the cockpit right in front of the user, and to the extent that its works make
We have a product that runs now on Rift, Vive, and PSVR and will soon on Daydream and upcoming mobile and Windows VR. Take my opinion for what it's worth.
Comfortable VR requires low-latency motion sensing, screen displays with pixels on/off for precise periods to avoid blur or flickering, simulation and rendering that is at least 60 fps, and asynchronous reprojection of that output to 90 or 120 hz. All of the above VR systems are capable of comfortable VR running applications that meet that framerate requirement. Many would additionally argue that head-position tracking is a requirement for comfortable VR, because otherwise the world "moves" with your head. We say it's definitely better to have than not, as long as it has the same low-latency as rotation sensing and is reliable.
Applications also need to minimize the difference between acceleration you see with your eyes and feel with your balance. Our research shows people have different trigger thresholds for simulation sickness, and different sensitivities to different types of acceleration (for instance most people can handle differences in forward acceleration than vertical, and both better than turning). Different applications have many ways to address this: low detail backgrounds or background occlusion when turning, "cockpits" that turn with you, shuttering of FOV to reduce peripheral detail when turning, teleporting, acceleration limits, head-synced turning, level design that encourages more or less accelerations and vertigo, room-scale only movement, etc. You will have to jump in yourself and find what you are capable of and what applications do the trick for you.
The rest comes down to features and ecosystem of each VR system. Hardware systems have been evolving very rapidly but here's a brief rundown.
Vive & Rift are very similar from sensing and screen and computing requirements,wide fields of view, high application framerates, They both now require a tether to your PC with I5-4590 & GTX 970 or better performance. Vive came out with full room-scale position sensing and two hand-controllers, which has led to a lot of great room-scale applications. Rift came out with built-in headphones which are key to enjoying the full VR experience, as sounds can be "binaurally" mixed to sound like they are coming from precise locations, and is lighter than Vive. There are a lot of Vive add-ons available now or soon that include face covers, wireless transmission, tracking pucks and alternate head mounts with headphones.
PSVR actually has a higher screen refresh (120 hz) than Vive & Rift (90 hz) which makes looking around (with async reprojection) feel more crisp. But most PSVR applications run at 60 fps rather than 90 fps like most Vive & Rift apps, which makes object animations and positional travel less crisp. PS4 Pro apps can hit 90 fps at about the same level of detail but that depends on the developer. The PSVR's screen might be the brighest and uses a different pixel technology, less little dots and more solid squares, that is a matter of taste. It's a little heavier than Vive but is balanced between front and back so the weight rests on your forehead--in fact its screen guard doesn't even touch your face like Vive & Rift, and can move out and in for easier use by glasses wearers. PSVR's position tracking relies on visible light which is a bit less robust than the other two, though all of them have problems in direct sunlight.
Microsoft VR is further out but looks to be aiming for PSVR level performance on PCs with less than Rift/Vive specs. A notable feature is "inside-out" position tracking, coming from their Hololens research, which doesn't require external cameras like Vive/Rift/PSVR.
Daydream on a Pixel phone (Snapdragon 821) is surprisingly good for mobile. In our tests it has about twice the power of S7 running on GearVR, which our application can't yet run on with sufficient detail. Its applications require 60 fps but it has asynchronous reprojection to what feels like a 90 hz screen refre