Game Development Reference
In-Depth Information
The concept of an AR game
Regarding the concept of a game, I would like to describe a less-common model of
using 3D content in AR. As a rule, 3D objects are shown on or above some physical
surfaces; figuratively speaking, such AR is convex. However, it is interesting to try to
create a concave reality by creating an illusion of a hole in a surface. Fiducials cre-
ate a boundary for such a virtual recess and players have the chance to look inside
the rabbit hole. The idea is manifested in the best way when markers are placed on a
wall, since the game creates an AR window where some virtual scene is shown. The
illusion is pretty smooth because the virtual image has a real-time response to change
the player's point of view and position is space of a camera; there are parallax, real
time linear perspective distortions, and so on.
Game content is perceived as a truly and natural addition to the real world. It is like
having a window into new dimension in your own room. Of course, a special step is
needed to process the final image because a mask should be used to cut off all the
faces of the 3D model that have to be invisible, but that should not be a big problem,
as long as the marker can provide the exact coordinates of the window.
The following image represent a schematic image of the AR window:
In an ideal scenario, the image recognition system in the game is smart and capable
enough to rotate any object in an AR window, that has contrast cadres; so players
may use framed pictures on walls or computer monitors. Since rotating objects can be
considered unrealizable for some reasons graphical markers can be used instead. It
is more efficient to use something similar to the ARtag system when several fiducials
are used at once, as such an approach will add some more reliability. For example,
the game will continue operating in conditions where only some of the markers are
within camera range.
The game scene looks like a diorama: a window-frustum shaped skybox with some
decorationsinsideandofcourse,afewcharacters.Itisgoodtomakeashootergame.
Several enemies are seen behind the AR window; players need to shoot them us-
