Information Technology Reference
In-Depth Information
will encounter when they follow an AR marker or launch an AR application to
look at a piece of work. The viewer can be exposed to undisclosed content that
is only revealed once the decision to view and the technological connection has
been made. The relationship between the viewer and the creator of the work must
be built on trust, experience, and an understanding of the media form. Therefore,
successful communication is contingent on establishing a context of use and the
setting up of expectations that relate to what is anticipated, and how a viewer might
respond/behave when the AR content is revealed. Creators of located AR need to be
mindful of both the viewer's expectations and the content of use.
In the following section we will look at different techniques for the generation
of AR graffiti and its potential in terms of storytelling through the creative use of
media.
11.4
Augmenting What and Where: Markers and Clues,
Techniques and Technologies
Early examples of AR used fiducial markers for the tracking and positioning of
the viewer or the viewing device. This allowed virtual content to be displayed in
relation to the point of view and position in physical space, and for the combining
of AR content on a digital screen (Bimber and Raskar
2005
). With the development
of more sophisticated image processing software and the utilization of combined
WiFi, cellular and GPS tracking, and 'Simultaneous Localization and Mapping'
technologies (SLAM), many AR applications that now run on mobile devices can
directly recognize the visual patterns incorporated within the shapes and images
of graffiti and street art. These technologies remove the need for physical/visual
markers to be placed in the physical environment. However, although abstract and
nonsensical in human terms, the small black and white squares or geometric shapes
of these conventional AR markers do operate as a useful device, in that they provided
a visual clue for people to recognize that AR content is available. With the new types
of 'transparent' AR markers - where almost everything you look at can effectively
be tagged with virtual content - the question is, how do we know when and where
to look for this content? In the urban environment the existing visual language of
graffiti and street art can operate as a useful device for indicating that virtual AR
content might also be available in a specific place.
With AR graffiti it is possible to make use of all the conventions of contemporary
digital media. Drawn and photographic visual media, computer-generated 3D mod-
els, typographic and information graphics, video, animation and audio content can
all be used in the creation of AR artworks. AR graffiti can use the potential of digital
image making and effects to extend, create and reveal new and additional stories
around conventionally made graffiti and street art. However, as observed in the
uptake of digital visual effects in mainstream media, the mapping of digital content
into realistic scenes needs to be carefully considered, managed and applied in such
a way that it adds to the experience of the viewer not detracts (McClean
2007
).
