Kelly B. Heaton and Robert D. Poor
Massachusetts Institute of Technology
20 Ames Street, E15-468
Cambridge, Massachusetts 02139 USA
firstname.lastname@example.org / email@example.com
Nami is a decentralized community of identical "orbs," each of which can
display various hues of colored light, respond to touch and wirelessly
communicate with its neighbors. A user activates the spread of color within
Nami by touching a single orb, whereupon the selected orb will respond
with the expression of a new color. The new state will be broadcast to
neighboring orbs, prompting them to assume the color and forward the message.
In this way, waves of colored light will move throughout the distributed
network of Nami and create beautiful patterns of behavior. There is no
"right" or "wrong" way to arrange Nami, as messages are relayed through
whatever pathways are made possible by the placement of the individual
orbs.1 The resulting combination of wireless communication, distributed
networking, and various patterns of colored light provides a new means
for graphical animation in the physical domain.
Computer Graphics in Sculpture
Computer-generated animations become possible when an artist can exercise
dynamic control over a large quantity of individual pixels. Although a
single changing pixel is uninteresting, increasing numbers of pixels will
manifest recognizable patterns when subjected to certain recursive algorithms.
These emergent behaviors can demonstrate life-like characteristics2, reminiscent
of the spread of gossip within a community or the ripple of waves across
a pond. Whereas traditional computer graphics are limited to the flat
space of a screen or projection, the integration of color animation into
a community of distributed objects denotes physical pixels, or "phyxels,"
whose behaviors are guided by the user's jurisdiction over a physical
system. Phyxels can be imagined as game pieces, building blocks, bricks
or other sculptural objects that can express mutable color in response
to user input and network structure. While the ubiquitous "beige box"
format of a computer limits an artist's ability to unite physical interface
with virtual form, phyxels are free to integrate their computational properties
with an appropriate tangible design. Like pixels, a phyxel is most interesting
when treated as a unit from which an overall structure can be built; but
whereas pixels can exhibit only virtual qualities, phyxels have both sculptural
form and animated features.
First Implementation of Nami
The degrees of freedom necessary to transpose computer graphical behaviors
onto a decentralized network of physical objects presented several challenges
to the Nami project. Each orb must be able to (1) respond to the user;
(2) exhibit the desired behavior; and (3), communicate with other orbs.
Capacitive touch-sensing3 seemed the most intuitive interface for the
Nami orbs, enabling the user to control an orb's state by simply cupping
the domed top. Each orb has a microcontroller to manage user interactions
and communication. A separate microcontroller modulates three LEDs (one
each of red, green and blue) to create different mixtures of colored light.
Considerable effort was put into creating a gentle and soothing blending
of color, so that the orbs would have an organic aesthetic suitable to
the wavelike behaviors from whence Nami derives its name. The physical
appearance of the orbs is similarly designed to have an undulating form,
reflective of the color waves that they carry.
In the first iteration of Nami, orbs were designed for wireless communication
over a limited distance within a plane; however, future research will
investigate alternate designs for a network of distributed physical objects.
The current Nami relies on fixed-format messaging for network communication;
the next generation of Nami will employ "mobile agents"4 to provide messages
that are executable software objects. This architecture will enhance design
flexibility and make Nami a useful test-bed for the visualization of distributed
networking algorithms. Several improvements are being made to the infrared
communication and touch sensors, and an inductive charging scheme is under
development. Forthcoming versions of Nami will also include an electronic
artist's palette, intended to enhance user control by providing a method
for specific color and pattern selection.
1 Robert Poor. Hyphos - A Self-Organizing Wireless Network. Master's
Thesis, MIT Media Laboratory. 1997. http://www.media..mit.edu/~r/projects/hyphos/
2 Harold Abelson, Thomas F. Knight, Gerald Jay Sussman. Amorphous Computing.
3 Rehmi Post. Personal communications.
4 Nelson Minar, Kwindla Hultman Kramer, Pattie Maes. Cooperating Mobile
Agents for Dynamic Network Routing. Chapter 12, Software Agents for Future
Communications Systems, Springer-Verlag, 1999, ISBN 3-540-65578-6. http://www.media.mit.edu/nelson/research/routes-bookchapter/