A Location and movement based videogame for Mobile Phones
2. Literature review
2.1 Location-based Media
2.2 Immediate/Intuitive input
3. Methodology & Evaluation
In recent years there has been a notable shift in the use of computers away from the
traditional desktop paradigm, which dominated the industry during the 80s and 90s.
The characteristics of what a computer is and what it can do have changed in copious
ways due to the development of smaller and more powerful components. Due to the
necessary size of the components for more powerful systems, computers were large
and immobile, or portable and feeble. In the late 90s the mobile phone exploded in
popularity, moving from a luxury item to a device that everyone could own. There
was now a computer in everyone’s pocket, but these devices were still of relatively
meager power and did not have the capacity to run programs other than those built in.
However, due to the irresistible market forces of more than 1 billion devices sold
every year, they have become massively more powerful in a short space of time.
General purpose computing mobile phones (Smartphones) that have the ability to run
applications programmed by the end user or software developers have been released,
and currently they have 10% of the total market.
In tandem with these advances, a number of innovations in the input field have
changed the way we use these devices. Gyroscopes and accelerometers have brought
a physicality to the use of the devices, and because they are handheld they go well
together. Nintendo have harnessed the power of accelerometers in conjunction with a
basic digital camera to create the motion-sensitive Wii, which has become the fastest
selling games machine of all time. Touchscreens have also gone mainstream, used in
most smartphones and also used by Nintendo in their portable games machine, the DS
which has now become the largest selling portable games machine thus far. Digital
cameras have come from expensive novelties at the beginning of the decade to the
point we are at now, when if any portable digital device is launched it is surprising if
it does not have a camera. Digital compass’ (magnetometer) have also started being
deployed in the latest smartphones which should lead to some interesting applications
in which knowledge of the orientation of the device is desirable, not least of which in
emerging Augmented Reality field.
Finally, there have been numerous advances in wireless communications, with mobile
phone data networks expanding in coverage and bandwidth thanks to the deployment
of 3G and 3.5G technologies such as HSDPA. Fast reliable internet anywhere is now
within reach. Complementing the cell networks, 802.11a/b/g/n (wi-fi) personal
wireless internet routers and the cooresponding necessarily small and efficient chips
for mobile devices like phones and games machines and more recently cameras and
televisions supplement the cell networks due to their still relatively higher cost
compared to fixed broadband, while also placing these devices on an internal home
network owned by the user. Bluetooth allows quick and easy inter-device
communication without the need for a network hub, and small GPS (global
positioning system) chips have been developed suitable for mobile devices, though
generally assisted by the phone network.
For the location-based game, we plan to use some or all of these assorted technologies
to create an experience of a traditional computer game, but set in the real world. The
success of Nintendo and the iPhone as a development platform is proof that the
immediacy and tangibility that these platforms provide is desirable. Not only will the
player be moving in real locations, they will be performing real actions. The aim is to
remove as many layers of abstraction between the player and the experience as is
possible, through the application of the technologies described above.
2. Literature Review
2.1 Location-based media
Location-based media have seen a dramatic rise over the decade, since the removal of
Selective Availability(SA) by the United States military, which owns and operates the
Global Positioning System (GPS) satellite constellation. SA was a form of signal
scrambling that limited the accuracy of non-military GPS receivers to stop them being
used by the enemy, but was turned off on May 1 2000. Geocaching was one of the
first non-navigation applications found for the signal, the first recorded instance of the
activity occurring two days after the deactivation of SA. The pursuit consists of a
form of treasure hunt, in which a waterproof container is hidden in a remote location
and participants are challenged to reach it. The container may contain anything,
money, photographs, or toys for example. Countless variations on the format now
exist, involving puzzles, webcams, and virtual stashes. One particularly interesting
twist on the format is XKCD’s Geohashing, which involves using an algorithm to
create an arbitrary set of GPS coordinates which are used as the site of a meeting for
users of the website.
All of the previous section’s examples can be implemented using a dedicated non-
programmable GPS unit. The next step is to get GPS into general-purpose
programmable devices, which will open up additional layers of possibilities, allowing
a computer program access to the coordinates. The original home for these were
Personal Digital Assistants (PDAs) such as Compaq’s iPaq with GPS hardware add-
ons, but recently GPS has become integrated into most smartphones and so, combined
with a decline in PDA popularity, development has switched to them.
Examples we have looked at range from the simplistic to the extremely elaborate.
Catch & Run is a simple computerized version of the children’s game, “Tag”. If any
two users of the game come within range of each other, they enter a chase game with
one of them assigned the role of the chaser, and one the role of the runner. More
elaborate is VirtualPunk, which claims to be the first location-aware Massively
Multiplayer Online Roleplaying Game (MMORPG), the online gaming genre of
which World of Warcraft is the most popular example. The game layers game items,
Non-Player Characters (NPCs) and enemies, as well as other players, onto a map of
the local area.
Finally, the integration of GPS, cameras, accelerometers and magnetometers into
smartphones have allowed for Augmented Reality (AR) applications, which mix the
virtual world with the real world by layering computer graphics over the input from
the device’s camera. GPS lets the program know where it is, while accelerometers and
magnetometers inform the program of the device’s orientation, which is important
when amalgamating the real and virtual visuals. One of the most advanced
applications of AR is Layar, a “reality browser” available for Google’s Android
mobile OS and the Apple iPhone. Layar is a platform which enables content providers
to provide users with location-aware information through their mobile phone. As the
user observes the real world through their phone via the camera, Layar places
information bubbles over the visuals, in the appropriate places. In commercial
gaming, Sony Europe’s Invizimals utilizes a camera attachment to bring the creatures
from the game into the player’s environment, but does not use any locative features
beyond the camera.
2.2 Immediate/intuitive input
Like digital cameras, accelerometers have become ubiquitous in portable consumer
electronics in just a short period of time. Nintendo’s Wii games machine uses a three
axis accelerometer to translate the player’s movement into control signals, as well as a
cheap digital camera to orientate the controller in 3D space relative to the television.
Wii Sports, a game provided with every Wii sold, emphasizes motion control and
plays down traditional button pressing gaming, with typically little or no input beyond
moving the controller. In 2008 Nintendo sold over 25 million consoles, the largest 1
years sales ever for a home games machine, and has advanced motion gameplay
further with accessories such as the Wii Balance Board, a surface on which the player
stands which detects pressure. Apple included an accelerometer in its iPhone and iPod
Touch devices to allow the them to switch from portrait and landscape mode without
pressing buttons, but since the platform was opened to development they can now be
used in a wide variety of applications. Even before the platform was officially opened,
open-source games utilized the accelerometer in games such as Wooden Labyrinth 3D
had shown its potential. In a recent software update for the platform, the gesture of
shaking the device has come to mean “undo” in the operating system, reminiscent of
the Etch-A-Sketch drawing children’s toy.
Touchscreens allow for more immediate and intuitive interfaces in digital devices,
and have been deployed as such by Nintendo in their DS portable console. In Brain
Training, the player can write their answer to puzzles using natural language using the
stylus provided. The game is specifically targeted at non-gamers and older people
who have no knowledge of typical game control conventions, making the experience
more immediate and relevant to the real world. A second advantage is that by moving
the controls to the display, you are free to reduce the overall footprint of your device.
Apple’s iPhone and iPod Touch only have one button on the front, permitting a much
larger display and and a smaller device. The OS also benefits from this, with less
clutter than typical interfaces which utilize softkeys as they need some screen to
illustrate their function. Pointer-based gaming, easy on computers with a mouse but
never recreated satisfactorily on consoles with gamepads, are easy using
touchscreens. An example of mobile phone touchscreen gaming include Fieldrunners,
a strategy game in which the player places guns on a battlefield, a difficult task to
streamline on a gamepad but simple with a mouse and now a touchscreen. The
location is selected directly by touching the desired location. Of final interest in the
touchscreen area is gestures, such as pinch zooming and flicking on the screen left
and right to navigate. Much like movement based control, but on a smaller scale,
gestures remove abstraction from an interface and make the UI work more like the
Cameras can be used as a form of input, and not just in the AR area. In Japan, QR
codes are a popular form of physical world hyperlink. The codes take the form of a
monochrome pattern in the shape of a square, which can be recognized by the
cameras of portable devices and translated by software into a small piece of
information, such as a web URL or email address. They are an interesting case of
providing a link from the real world into the virtual. Modern GPS equipped
smartphones also have a Geotagging feature, attaching the GPS coordinates of the
location of a photograph into the picture’s metadata. Sony have also had a take on
motion based gaming using Eyetoy, a digital video camera attached to the console.
The low resolution of this camera made it an imprecise but fun method of control that
precipitated the rise of the Wii. More recently Sony has released the Playstation Eye,
and upgraded high definition camera for Playstation 3 that allows more precise input.
Methodology & Evaluation
There are a couple of different approaches to achieve a location and motion based
game using current digital devices. The devices that carry the most technology
applicable to the problem are the latest generation of smartphones, such as Apple’s
iPhone 3GS and the latest Google Android-based devices such as HTC’s Hero. The
choice between developing for the iPhone and Android has a couple of facets to it.
Android development is advantageous in that it is an open platform, with no
restrictions on running your own code on the devices. The underlying Linux nature of
the system has encouraged a culture of open-source development. Due to the many
different hardware devices Android runs on, development can be more complex than
iPhone, developing for which involves supporting more generally uniform hardware.
There is a development fee to allow access to the iPhone app store. These concerns
are largely only a worry if the project were to go commercial, I’m not sure if it is a
worry for a research project.
One way to sidestep the platform issues would be to make it a web app. The iPhone
and Android web browsers support location service requests from web pages. While
using a web app would be limiting from speed and power perspectives, and having
less access to the device’s other input sensors. I have much more experience creating
web pages than coding applications, so this may be a less troublesome method of
running the game, but it would require access to the mobile phone data network while
a native application could run offline.
A third option would be to aim solely at the location based game, specifically with
geotagged pictures. This would broaden the focus from smartphones to any device
that can take geotagged photos. The front-end would be a standard website, with
pictures being uploadable from anywhere and any device.
The choice seems to come down to doing many things poorly or focus on fewer
features but better functionality. To avoid this dichotomy, I propose to make the
project modular and scalable, as far as is possible. Things are too vague right now to
establish precisely how this may be done, but I would prioritize the objectives like
1) Locative – Use of GPS features in an intelligent and innovative manner.
2) Gestures – Use of both accelerometer and touchscreen gestures in a natural
fashion that enhance the real world/virtual world fusion.
3) Augmented Reality – The final step in meshing reality with the virtual, I fear
this is an order of magnitude more difficult to employ versus my other
objectives. Further research is needed but AR would be low on my list of
priorities relative to the others.
By taking a modular layered approach I hope to create something that works
well, and with the maximum level of desired features that is possible in the
timeframe and with my skillset. Above all I want to produce something that
works over something that is potentially more interesting but doesn’t.