Virtual Reality Glossary of Terms

Any reasonably complex field has its own set of catchphrases and keywords. The world of virtual reality, often abbreviated as VR, is no different. The terminology used in VR runs the gamut from the technical to the philosophical. While virtual reality systems are operated by sophisticated technology, the design of the worlds and games is more aspirational. VR experiences may be designed to re-create the physical world, or they may seek to deliver the player to an entirely new place. Fortunately, exposure to some of the more common words and concepts can help you navigate this strange and fascinating ecosystem.

Augmented Reality (AR): A sort of “light” version of virtual reality, AR incorporates virtual content into the real world. Some AR apps on mobile devices allow users to see how a new sofa will look in their own home. Others are more fantastical, such as making dinosaurs appear on city streets.

Avatar: An avatar is a VR user’s representation in the virtual world. While avatars in some online services may be simplistic and cartoonish, VR avatars are different. In virtual reality, the user needs to see a virtual representation of their hands, for instance. This allows the user to interact with objects in the virtual world.

Collision Detection: Without collision detection, the VR user would pass through virtual objects without effect. This lack of physical interaction would prevent the user from undergoing a properly immersive experience. When the player presses a button in VR, collision detection tells the game that the button should activate.

Eye-Tracking: VR systems have increasingly sophisticated eye-tracking systems, which tell the application where the participant is looking. This is useful for prioritizing system resources. For example, the VR system might render parts of the scene in full detail but other parts in reduced resolution or not at all. Knowing where the user is looking helps the system makes these decisions. Eye tracking is also useful in VR training, such as for pilots. Tracking where the trainee looks can tell the trainer whether they are paying attention to the right things.

Field of View (FOV): The width of the user’s visual plane is called their field of view. Human vision has a field of view of about 220 degrees, including direct sight and peripheral vision. A wider FOV makes the virtual world’s visual information more like reality, boosting immersion. Because FOV determines how much of the virtual world the user can see, manufacturers are constantly pushing to increase it.

Gesture: Any bodily motion that controls or influences VR content is called a gesture. A user might wave their hand at a virtual door to make it open, for instance, or lean forward to simulate walking.

Haptics: While VR goggles and headphones deliver visual and auditory information, haptics inform the sense of touch. VR devices use motors or vibrations to simulate touch. Adding a third sense to the mix increases immersion and expands the range of VR experiences.

Immersion: When all of the elements of a VR experience combine effectively, we say the experience is immersive. This means that the user encounters a convincing virtual world, even if it requires some suspension of disbelief. In theory, true immersion is achieved when the sensory inputs from the VR system are indistinguishable from reality.

Locomotion: In virtual reality technology experiences, physical movement is often restricted. There are practical reasons for this, as most participants operate VR gear in relatively enclosed spaces, such as a room in their house. There are also safety reasons, to prevent users from wandering into danger in the real world. Locomotion in VR is therefore achieved by simulation. That could entail the user teleporting from one place to another or simulating walking by shuffling their feet..

Peripheral: Hardware add-ons to a VR system are called peripherals. For virtual reality, these add-ons often enable additional methods of controlling the experience. Some controllers attach to the arm, allowing more detailed movements to be duplicated in the virtual world. Others permit the user to move or tilt their feet to activate a walking animation in VR.

Presence: While immersion concerns the effectiveness of the VR illusion, presence is about how the user feels within the virtual world. An effective VR system can make the experience less like watching a film and more like being present in another place. The user reacts to the virtual world much as they would to the real world, making similar choices based on their goals and personal risk analysis.

Virtual Reality: Virtual reality is the use of technology to deliver sensory information. Often, the goal of this sensory information is to convey a simulated, or virtual, world. The user is then able to interact with the virtual world in a variety of ways. Some systems feature controllers that the user holds in their hands, while others track the user’s movements.