IV. INTERACTION DESIGN
A. Interface/Interaction implementation
The tablet application supports two main view modes:
”Map” and ”Field” view, which correspond to a top-down and
eye-height level perspective of the environment respectively.
In Field Mode, Virtual and Augmented views (VR/AR) are
available. Both include a virtual reconstruction of the camp
in two historical states: 1944-1945. In AR mode the virtual
reconstruction as well as its annotation are combined with the
tablet’s camera video image of the present-day environment,
providing an immersive impression of the state of the camp
in 1944-1945. Both map and field view modes are available
through tapping a smaller window at the bottom center of the
screen (Fig. 3).
Information accessibility is restricted with a proximity
condition (⇠10 meters) to promote physical movement through
the environment. The distance of available information is
informed to the users in the Map View through a circular area
that surrounds their indicated position in the map. If a moving
visitor brings his circle close enough to a PP icon, the content
is made available.
Fig. 3. Top bar shows icons with different positions, sizes and colors
indicating different content times, distances and states of availability.
Since the platform application is aimed at the navigation
through large sets of data, large amounts of icons at various
distances create cases in which the 2D layout becomes unclear.
Although the map view helps identifying icon’s relative position
from each other, our aim was to maximize the field view in
order to promote the bodily actions of turning and translating
oneself in the environment. We conceptualized a horizontal bar
in which duplicate icons hover above their relative position in
the perspective, which also helps to reveal content momentarily
occluded by buildings. Both icons in the field and in the bar
resize according to their distance to the viewer, indicating
distances, and have different graphical representations to show
different historical times. The top bar also provides the main
access to the content: when a POC becomes available as the
result of proximity, a thumbnail opens under the highlighted
icon, which then can be clicked to open a fullscreen content
view. Once a document has been open, it can be saved into
the user’s list of bookmarked items and remains accessible for
the rest of the session in a lateral, slidable tab (Fig. 3).
The top bar system was also designed to solve the problem
of unreachable locations due to inaccessible parts of the
environment. Typically, outdoor environments pose limitations
to direct content accessibility due to trees, mud, elevations
and so on. In such cases a looking direction (vector) that is
associated to the PP is a good solution, and the horizontal top
bar serves the purpose of directing people’s gaze.