Wiki
This page gives an overview of terms and concepts important to know in the domain around VR and AR.
The content depicted is based on publicly accessible information about the technological status quo of March 2020.
Augmented Reality
Definition
: Augmented Reality is an enhanced version of reality created by the use of technology to overlay digital information on an image of something being viewed through a device (such as a smartphone camera) (Merriam-Webster Dictionary, 2020)
: Augmented reality, commonly abbreviated “AR”, is computer-generated content overlaid on a real world environment. (TechTerms, 2020)
Hardware
Augmented Reality can be facilitated by various devices: handheld devices (smartphones, tablets), headsets or glasses, and externally mounted projectors. In the future, even AR lenses with direct eye contact might be feasible.
There are generally two types of devices: devices supporting 2D and 3D graphics. Glasses referred to as standard AR glasses mostly support the projection of 2D information onto the real world. 2D AR devices are generally lighter and cheaper than 3D devices. Examples are Google glasses, Epson mover, or Focals by North. The Focals by North are one of the first combining regular glasses with AR features for the consumer market.
The most popular AR headset with 3D projection capability is currently the Microsoft Hololens, since it uses a see-through display. However, the Hololens is mostly used for industrial and research projects and has not yet entered the consumer market. Another headsets with 3D projection capacity are the magic leap.
Since 3D devices fully integrate information with the real world, it is often referred to as an enhanced concept of AR: Mixed Reality
A well researched general overview of AR glasses can be accessed here.
Software
Generally, AR software can be separated into development tools and viewing tools.
Development tools include development platforms such as Unity3D, or UnrealEngine. In addition, development kits for the specific viewing devices’ operating systems are needed. AR kits include for example ARKit (iOS), ARCore (Google), or ARStudio (Android). There exist further software tools which are specifically designed to support user-friendly, no-coding AR content creation such as SparkAR (by Facebook for Instagram content), or ROAR IO (for marketing content).
With most development kits customised apps can be created which serve as the AR execution tools. Moreover, most social media platforms are working on seamlessly integrating AR functionalities into their standard features. However, some tools require the user to download dedicated AR player apps, e.g. SparkAR player or the ROAR and Augment viewing app.
Virtual Reality
Definition
: Virtual Reality (VR) describes a technology-enabled artificial environment in which a user can get fully immersed, usually via headsets providing audio-visual stimuli
Hardware
There is a variety of VR headsets available on the market. The price ranges significantly based on the provided resolution and processing power: Valve Index (£££), HTC Vive (£££), Oculus Quest / Rift S (by Facebook, ££), Playstation VR (£).
Beyond the use of headsets, controllers are required to act within VR simulations. Moreover, haptic feedback devices e.g. force-feedback gloves, are gaining increasing popularity. Haptic feedback adds an additional sensorial dimension which increases the immersive potential of the overall simulation.
Software
Similarly to AR, the most common development platforms for VR are Unity3D and Unreal Engine. Unity3D is popular for its user friendly interface. Unity requires C# programming skills, whereas Unreal Engine uses C++.
For the creation of 3D models most availably CAD (computer aided design) and 3D modelling tools can be used, e.g. Blender, SketchUp, Cinema 4D, AutoCAD, Creo, Siemens NX etc.
VR Concepts to know
Field of View: The range of vision any VR headset has. Human eye: about 200 degrees
Focal Length: The distance between your eyes and the display, crucial for the perception of the optimal image sharpness.
Interpupillary Distance (IPD): The distance between the pupils of both eyes: to calculate the difference in viewing angle needed to create a stereoscopic 3D image
Refresh Rate: How fast moving images are shown. Higher refresh rates can cut down latency. Target <60 frames p/s to avoid motion sickness
Latency: The time a VR headset takes between receiving an input and updating its display. Reality: 0 ms; VR, latency should be >20 ms
Tracking: Sensor-enabled eye, position, and head tracking allows the headset to adjust the visual output to the user‘s point of view