VR and UX
We are living interesting times. Many technologies which we have only seen in a science fiction are now in the hands of millions of people. Google’s Daydream platform, all Daydream compatible devices and Apple’s iOS11, macOS High Sierra, new iDevices bring many amazing new features into our pockets in a form of augmented and virtual reality.
Oculus Rift, Microsoft HoloLense, HTC Vive are good examples of premium VR and AR head mounted displays (HMD) which already are available for average consumers. There are other entry level headsets like Google Cardboard, Daydream View or Samsung Gear VR which use mobile phones to display VR world. The latter options costs from few coins to around 100 euros and makes VR more tangible for everyone who own a smartphone.
Game industry is usually the first one to utilize new technology. Virtual reality gaming has been around for years already. SteamVR is one of the most popular VR gaming platforms at the time of writing this post.
Even though games are cool and we have seen amazing demos utilizing AR, VR and XR, I think we are just in the beginning the Artificial Reality journey. I am eager to see and try applications utilizing Mixed or Extended Reality to solve actual real-life problems.
This is one of the reasons why I started to study these technologies to understand better UX design process - what freedom it brings to the UX design, what constraints there are and how challenging it is. One of my goals is to educate myself to understand this application area better and understand the UX design principles of the VR.
Virtual Reality UX design
UX design for virtual reality is challenging in many ways compared to a traditional UX design. In real world, user interacts with a device either using an input device like a mouse or a touch screen. In virtual reality there are no similar controls for interaction because everything is rendered around a user. User is also inside a virtual environment which means that the UX design must consider the following VR properties or design details:
- Depth or a distance as a 3rd dimension
- Larger field of view and 360 degrees world
- How to use sound
The depth or a distance makes UX design in VR hard because it effects to many things. Where to put objects to make them easily reachable or visible for a user. How far or close items should be — how far is too far, how close is too close. How to prevent user to get exhausted if she spends long periods of time in VR enviroment.
Larger field of view and 360° world is another challenge in the UX design for VR. User can rotate her head comfortable approximately 55° to the left and right or the whole body can turn 360° but viewing area is still smaller, all user interface items should be placed in the VR world to be easily accessible and accessing them should be effortless for the user.
Sound is not a new thing. It’s can be used for many things and feedback is one of those. However, sound design is more important in VR than in traditional UX design. In VR sound can help user to understand surroundings or give feedback even faster than any visual feedback. You can close or blink your eyes, but you can’t turn off your ears. That’s why sound design should never be underestimated or leave it out from the UX design process.
Virtual Reality Ergonomics
Good ergonomics is one of the most important design guidelines in VR. Badly designed UX can literally make user feel sick. Even the best VR hardware can’t prevent improperly designed UX to make a user to feel uncomfortable. That’s why it’s good to start with the basics. Many “rules” for VR ergonomics are based on the real-life ergonomics but they are applicable to the VR field too.
The following illustration from Mike Alger’s study, points quite well the limits for different zones and where to place content around the user either horizontally or vertically. Content here means items like a text or menus to interact with.
No-No Zone is an area within 0.5m radius from the user. This area should never contain any permanent content to interact with. Note that there can be exceptions, but those should be temporary only and evaluated case by case.
Main Content Zone is an area which is “comfortable” for user to see and interact with a content. User doesn’t need to rotate her head too much in order to see items in this area. The comfortable viewing area is 30° from center to the left or right and max rotation is 55°. Rotation of 30° combined with the device’s field of view gives an area in which a user can comfortably rotate their head and see elements, 77° to the side from the center .
I noticed that Oculus Rift and HTC Vive have only 110° field of view which forces user to move head more and sets constrains for the UX design too. There are also other headsets in the market such as Pimax which has 200° field of view and it naturally improves user experience a lot.
Distance effects also to a human ability to see a stereoscopic separation (3D). The further objects are the more difficult it is to see the separation. Objects appear to be flat if they are more than 20 meters away from the user. If an object is closer than 10 meters, then stereo separation should be clearly visible. This is quite important information when designing UX and scenes for the VR.
Peripheral Zones are areas where user can see stuff if she turns her head. It should be avoided to put any necessary items in that zone.
Curiosity Zone requires that user turns her body to see the area and it shouldn’t be used for any permanent items.
Vertical positioning in VR is also important to understand in UX design. Placing objects to vertically to inconvenient positions like too high or too low makes user feel uncomfortable after some time. Human eye rests naturally approximately 6° below the horizon . Traditional office ergonomic proposes that the most optimal angle for a display is around 15°–55° below horizon line. These same guidelines can be applied for VR when designing vertical positioning of items.
Because people spend time in VR, it’s important to place items such as menus to a location where they area easily accessible and eyes don’t need do extra work to focus on them. Human eye focuses naturally approximately to 1.3 meters and is usually the optimal distance to place text or other items which user may need to watch for an extended time. According to Oculus Rift documentation, they recommend to render menu items from 0.75m to 3.5m distance from a user .
Virtual Reality Input Devices
Input device in VR means a device which can be used for interacting with the VR environment and objects in it. There are huge amount of different devices in todays market e.g. gloves, suits and other technologies for VR input, but we cover only a few here.
Leap Motion is a technology which tracks hand movement using two cameras and three infrared LEDs. Cameras track infrared light with a wavelength of 850 nanometers, which is outside the visible light spectrum. Leap motion viewing range is approximately 80cm (2.6 feets) which should be enough to track hands of the most of the people .
Cool thing about Leap Motion technology is that it’s an intuitive way to interact with virtual objects in the virtual world. It feels natural, but haptic feedback may be tricky and it’s probably good idea to have both visual and audible feedback for certain objects. Designing interactive objects for this technology is not trivial. Objects should always be responsive but it’s also important to hint user which objects can be interacted with.
Designers can use commonly known UI components (== boring approach) and create visual helpers (lighting & shadows) to understand how they work. For example change a hand semi-transparent near to UI elements or place an item to the natural viewing area closer to user. One option is to highlight an item when user “focuses” to it by moving a HMD .
Personally I think that Leap Motion interaction is only limited to the 80cm radius from the user in real world, but in virtual world it’s a different case. Using imagination, user can reach objects which are futher away. A hand can act as a controller for a “virtual controller”, which can reach items located very far from the user. So even though technology sets constraints for the physical world, in VR those constraints can be overtaken.
HTC Vive, Oculus Rift and Google Daydream View have handheld controllers which are used for interacting with a virtual world. Compared to Leap Motion technology, these physical controllers are not that intuitive to use but they can provide more functionality and it’s easier to interact with objects which are not very close to a user.
Physical controls good for gaming, at least when you have developed a good muscle memory and you don’t need to think about what button to press. Naturally there is a learning curve but even a basic game controller for traditional game consoles are sometimes complex to master perfectly.
I don’t go any deeper regarding to input devices, but I’m personally more interested about Leap Motion type of technology or maybe some sort of a hybrid of a motion tracking and a controller. Another interesting way to control virtual reality is using voice commands but I haven’t yet studied that enough.
Designing Screen Interfaces for VR
I found a pretty good video from Google I/O 2017 where UX designers from Google explain how they figured out how to create a distance independent screens. They come up with an unit called:
dmm = Distance-Independent millimeter
The idea (in a nutshell) is that designer doesn’t need to care about the distance where the screen is intended to be viewed. Screens are designed using using dmm and they can be scaled correctly based on the distance. With this approach e.g. text is always readable regardless of the distance.
I don’t want to go through to all details in this post (which already is a way too long) so here is the video to explain the theory part and it shows an example how the desing can be done in practice.
There is still one more thing to mention here and it’s the resolution of the VR headsets. Resolution is very important for a good UX. Low resolution also sets certain limits for VR and in the worst case, it can make people to feel uncomfortable.
There are companies currently working on high resolution headsets. Pimax is working on 8K (3840 x 2160 x 2) headset with 200° viewing area, which is quite impressive and according to few videos, the UX is really amazing with that headset.
Another company, Varjo is a Finnish start-up founded by ex-Nokians and they are working on a hardware and software solution to mix the real world to an extended reality and into pure virtual reality in human eye resolution.
“Our patented Bionic Display™ technology mimics the natural behaviour of the human eye and allows us to create products with up to 100 times the resolution of any of today’s VR/AR devices.”
To promote Finnish entrepreneurship, here is Varjo’s promotinal video. Video is pretty cool even though it’s just a marketing stuff but I’m eager to see what they will release later this year.
When googling about VR, it’s not difficult to notice that AR, VR and XR are very hot topics at the moment. It’s also nice to see that it’s not just a playground for big players like Microsoft, Google or Apple. There is still plenty of room for innovation and smaller players like Varjo and Pimax. I find VR really interesting area and especially the UX desing is very challenging area to make it right. I hope my little study in a form of this blog post has been interesting. It truly has been interesting journey for me.
Thanks for reading my blog!
 Visual Design Methods by Mike Alger
 Oculust Rift Introduction to the best practices https://developer.oculus.com/design/latest/concepts/bp_intro/
 Leap Motion blog: http://blog.leapmotion.com/designing-physical-interactions-for-objects-that-dont-exist/
 Google: Designing Screen Interfaces for VR: https://www.youtube.com/watch?v=ES9jArHRFHQ&t=841s