Characteristics of AR systems

Applications Types of AR Issues in AR

Human Factors 2: Augmented Reality

Augmented Reality Characteristics

Combines real and virtual: virtual objects superimposed or composited with the real world (adding and/or removing)

Interactive in real time Registered in 3-D In contrast to VE’s, AR supplements reality rather than

replacing it

Components of an AR system

NB: AR can be applied to all senses. There are systems that are being developed that can

accommodate sound, in which the user wears headphones equipped with microphones.

Why use AR?

The information conveyed by the virtual objects helps the user perform real-world tasks. It provides information to the user that is not directly available to the user’s senses otherwise.

Applications

Medical: project non-invasive imaging scans (MRI, CT, ultrasound) onto the patient’s body - “x-ray vision”. Particularly useful for minimally invasive surgery. Also for guiding precision surgery or training.

ultrasound guided needle biopsy

Applications

Assembly, maintenance and repair: Instructions available on-site as superimposed 3D drawings (video)

Applications

Visualization: e.g. architects may visualize how a particular structure will change the view of the environment. Or they may employ “x-ray vision” to visualize pipes, electric lines or structural supports inside walls (video).

Annotation: tag objects or enviroments with public or private information. E.g. a context sensitive (hand-held) display could provide info on library books as the user walks around a library.

object IDobject ID

NaviCam [Rekimoto, UIST’94]

context-sensitive information assistant

Applications

Robot path planning: due to long communication delays with a real robot, controlling the virtual version may be preferable

Military aircraft: superimpose vector graphics onto the pilot’s view of the world

Entertainment: e.g. virtual sets merging real actors with virtual backgrounds

Applications

Wearable computing: context-sensitive & mobile

http://www.microopticalcorp.com/

Types

Optical see-through HMD Video see-through HMD Monitor based AR

Optical See-Through HMD

Video See-Through HMD

Monitor based AR

Issues in AR

What’s wrong with this picture?

Issues in AR

WIMP interface is fundamentally wrong for AR Users are very sensitive to visual offsets (<1 min of arc) -

HMD trackers and displays cannot provide this level of accuracy: the registration problem (not so much a problem in VE’s). Note that some applications will demand high accuracy! Static errors: optical distortion; errors in tracking; misalignments Dynamic errors: end-to-end system latency (pot. solutions: lag

reduction; temporal stream matching (only w. video based systems); location prediction)

AR is in its infancy: No turnkey, off-the-shelf AR systems available; much research still needed on perceptual, cognitive and social issues