Designing Augmented Reality Apps:>> Comfort Zones, Interfaces, and Text
Augmented reality (AR) applications are already emerging. Augmented reality technology is hard to develop because we don’t understand all the applications yet. And that’s all the more reason to experiment to see how augmented reality will really come in handy. Keep reading for comfort zones, interfaces, and scripts in AR apps.
AR Application Design: Understanding Comfort Zones
It is important to understand the interaction of users within their comfort zones, especially for augmented reality applications that may focus more on getting work done. You also need to understand the differences between the comfort zones of interacting with a head-mounted AR versus the comfort zones of interacting with an AR on a mobile device.
Head-mounted augmented reality experiences are somewhat similar to virtual reality experiences, with a few exceptions. You need to reduce the amount of users required to move their heads for any experiences longer than a few minutes. Although their work has focused on virtual reality, Google VR designer Mike Alger and Alex Chu of Samsung Research claim users’ comfort level when rotating their heads horizontally is 30 degrees to each side, with a maximum rotation of 55 degrees. For vertical movement, a 20° upward rotation is comfortable, with a maximum upward rotation of 60°. Comfortable downward rotation about 12 degrees and a maximum of 40 degrees.
When determining your comfort zones for head-mounted augmented reality, it is also important to consider how you will use your application. Will it require direct interaction from users, such as hand tracking and gestures, or just pointing and clicking via the controller or touchpad? If direct interaction is required, consider how you can comfortably use that, especially if the app is intended for prolonged use. As more and more AR applications rely on utility, this consideration will become even more important.
A report on office ergonomics by Dennis Ankrum provides a good guide for augmented reality experiences that require user interaction, especially AR applications designed for use with (or as an alternative to) traditional computer use. Ankrum lists the correct eye-screen distance for most users as 25 inches from the eye, preferably more, and optimal placement of monitors 15 to 25 degrees below the horizontal plane of the user’s eye, resulting in a small “comfort area” for AR experiences while seated.
Meta has completed similar studies and achieved similar results with its headphones for the standing and sitting trials. An “ideal content area” is located between an intersection where the user’s hand will be detected by the headset, the field of view of the headset itself, and the comfortable viewing angle of the user’s line of sight. Each headset is slightly different, but in general, the ergonomics of a comfortable AR headset experience apply to most platforms.
The tracking technology used for hand tracking in Meta 2 has a detection area of 68 degrees, optimized at 0.35m and 0.55m distances from the user. Combined with the headset’s 40° vertical field of view, an ideal content area can be created at the intersection of what is comfortable for the user to reach and see.
This interaction comfort zone is not the same for every AR headset, but the identification of these areas will be similar to any current or future headset. Carefully consider how much user traffic and interaction your app requires and what comfort zones your devices may have. Take care to reduce the amount of neck rotation or unnecessary user movement. The first time a user has to have access to “turn on” a virtual light bulb in an augmented reality experience may be new. If the user has to perform this action multiple times, it quickly becomes boring.
Hint
“The comfort zones of a mobile device are very different from those of head-mounted AR devices. In the mobile AR experience, the user has to hold their device a certain distance in front of their eyes and button their arm or head to gain insight into the augmented environment inside the device. Carrying the device this way can be quite cumbersome after a while, so try to find a way to reduce user discomfort. If your application requires a great deal of user movement or long periods during which the user has to hold their device in front of them, find ways to provide breaks to allow the user to rest their arms a bit before continuing.”
AR Application Design: UI Patterns
Best practices for AR user interface design are still being defined. There are not many specific user experience (UX) patterns that augmented reality designers can refer to as best practices for what a user should expect when entering into an augmented experience. In addition, AR is a completely new form factor, different from the 2D screens people are accustomed to. Augmented reality will enable people to completely rethink the way we approach user interface (UI) design.
The two-dimensional world of the computer consists of flat layouts with multi-dimensional two-dimensional windows and menus. Augmented reality allows developers to take advantage of 3D space. When designing your AR user interface, consider creating a spatial interface and arranging your UI tools and content around the user in 3D, rather than the framed interface that computer screens are currently limited to. Consider allowing the user to use the 3D space as an organizational tool for their items, rather than hiding content or nesting it in folders or directories – a common practice in today’s 2D user interfaces. Augmented reality has ways to safely avoid masking content.
Instead of hiding the menus inside other objects, use the physical environment available to you to organize your setup. Hidden menus in 2D screens are usually created due to space limitations or the designer’s feeling that the amount of content will be overwhelming to the user. For enhanced experiences in situations of what you might consider an overwhelming amount of information, consider organizing items into groups in a 3D space.
Hint
“Instead of including content within menus, explore the possibility of minimizing the content to improve the space around the user. Content that would normally take up a lot of space can be made small until the user expresses a desire to interact with it.”
This does not mean that you can always avoid hidden or nested structures. Both will likely always be present in UX designs for augmented reality. If you find the need to include content, try to keep nesting levels to a minimum.
In most traditional 2D user interfaces, the nested content is given. In a traditional computer, users are quite accustomed to having to click four or five different nested directories to locate a file. However, the deep overlapping of content can be very confusing for end users, especially in the 3D environment of augmented reality. A user who has to navigate a 3D space through multiple overlapping elements will likely quickly get frustrated with the experience. Shallow nesting and easily accessible elements within the spatial environment should allow users to quickly retrieve content.
Warning
“Limit expandable and hidden menus as much as possible in the AR space. These patterns may have worked well in 2D screens in the past, but they are not necessarily relevant to the 3D world that augmented reality is trying to simulate. Expandable/hidden menus can introduce a level of complexity that you should avoid, if possible.”
The windowed two-dimensional world of today’s computing user interfaces has accustomed us to the two-dimensional icons and abstract shapes that represent real-world tools. These icons can also often hide other functions, such as expandable or hidden menus. However, the world of augmented reality is full of new modes for users to learn. Try to avoid creating a new system of 2D symbols for the augmented reality experience. This can force users to guess and learn about a system you created that may not be relevant to them.
Hint
“If the tool is intended to be used within the 3D space of the experiment, replace the abstract icons or buttons with 3D objects in space that give the user a sense of the tool’s purpose. Look to real-world environments such as drafting offices or art studios for inspiration. Realistic workspaces can provide examples of how real 3D objects are organized in a physical environment, which the user interface in augmented reality will generally attempt to emulate.”
Finally, enable the user to customize and organize their spaces in the way they find comfortable, in the same way they can organize physical desktops or work areas at home or work. This will increase the likelihood that she will be comfortable using the system you created.
Understanding text in augmented reality
Carefully consider the length and legibility of the text when creating your AR app, and review it while testing on as many hardware platforms and as many environmental conditions as possible. You probably won’t know what kind of environment your app will be running in. Is an area too dark at night? Too bright room in the middle of the day? To make sure your text can be seen, consider placing it on a contrasting-colored background.
The text size and typeface (font) can also affect text legibility. In general, you should opt for shorter headlines or shorter blocks of text whenever possible. However, many AR applications are utility based, and sometimes involve consuming large blocks of text, so ultimately designers will have to find a way to make long-form text documents manageable in AR.
If long document consumption is required for your application, make sure that the font size is large enough that the user can read it comfortably. (Meta recommends a minimum font size of at least 1cm in height when the text is 0.5 meter from the user’s eye.) Avoid overly complicated calligraphic fonts. Instead, stick with utilizing simple serif or sans-serif fonts for these large text blocks. In addition, narrower columns of text are preferable to wider columns.
Rapid serial visual presentation (RSVP) speed reading is a method of showing a document to a user a single word at a time. This could prove to be a good way of consuming large blocks of text in AR, because it allows a single word to be larger and more recognizable, instead of forcing your application to account for displaying these large blocks of text.
For any informational or instructional text display, try to favor conversational terms that most users would understand over more technical terms that may confuse a user. “Unable to find a surface to place your object. Try moving your phone around slowly” is preferable to “Plane detection failed. Please detect plane.”
AR app design: Testing, testing, 1, 2, 3
AR applications are still defining what make an interaction good or bad. So, you’ll often need to work from your own assumptions, and then test those assumptions as frequently as possible. Testing with multiple audiences will help reveal what’s working well and what you may need to go back to the drawing board with. When testing your application, give your test users only the same amount of information a standard user of your application would receive. Letting your testers try to use the app without assistance will help prevent you from inadvertently “guiding” them through your application and will result in more accurate test results.