Bar Code Hotel is an interactive installation for multiple participants (or guests). By covering an entire room with printed bar code symbols, an environment is created in which every surface becomes a responsive membrane, making up an immersive interface that can be used simultaneously by a number of people to control and respond to a projected real-time computer-generated stereoscopic three-dimensional world.

View Quicktime Movies of Bar Code Hotel.
View Screen Images of Bar Code Hotel.
View Installation Shots of Bar Code Hotel.

Origins Of The Project

Bar Code Hotel was produced under the auspices of the Art and Virtual Environments Project at the Banff Centre for the Arts, in Alberta, Canada.

Upon arrival at the Banff Centre, one is issued an ID card with a photograph and a bar code symbol, which is passed through bar code readers in various locations for various purposes. One afternoon, I swiped my card to pay for a meal, and was promptly informed that I had received some messages. I'd never thought much about bar code before, but it struck me as strange that such entirely different functions could be conjoined.

I started to research bar code technologies, and began to visualize a room in which every available surface was covered with bar code, an entirely black-and-white environment. At this point, I still wasn't sure what the bar code would actually do, but I assumed I'd think of something. I went ahead and ordered my first bar code reader, and began to decipher the various available symbologies. We even discovered that we could actually (somewhat laboriously) write readable bar codes by hand.

What is Bar Code?

Bar code is the ubiquitous system of black and white stripes that is branded onto the surface of every single salable item in the western world. Introduced in the early 1970s and substantially unchanged since then, bar code appears timeless, almost style-free. The Universal Product Code organizes all consumables into an exhaustive digital hierarchy that interfaces seamlessly with an ever-growing network of computer systems that can track everything from vast warehoused inventories to the minutiae of individual consumers' choices and whims.

Why Bar Code?

Like any technology, bar code can be enlisted for other, less practical purposes. Misusing something that is normally in the service of control and authority holds the potential to reveal other, less constrictive scenarios. Of course, the ominous overtones of its intended use remain at least faintly audible.

Bar code represents an early attempt to bridge the gap between the physical world and the computer. As such, it is the forerunner of present-day attempts to allow computer comprehension of the world as it is (such as optical character recognition and artificial vision), as well as plans to embed digital information invisibly in the environment (ubiquitous computing and augmented reality).

Unlike these contemporary projects (which strive for subtlety, invisibility, a policy of non-intrusion) bar code is blatantly, unavoidably obvious. In fact, this very obviousness became its appeal to me. Bar code makes no attempt to disguise its sole function as an extension of the domain of the digital computer.

As my ideas developed, I started to think of using bar code technology as a kind of caricature of a more conventional virtual reality apparatus. Participants would be "immersed" in a computer-generated world; but this world, instead of being made up of virtual polygonal objects, would be made up of printed black and white symbols. The bar code wands were a kind of cheap substitute for a data glove. Finally, I decided to incorporate 3D projection, necessitating 3D glasses as a surrogate for the inevitable head-mounted display.

The Interface

Each guest who checks into the Bar Code Hotel dons a pair of 3D glasses and picks up a bar code wand, a lightweight pen with the ability to scan and transmit printed bar code information instantaneously into the computer system. Because each wand can be distinguished by the system as a separate input device, each guest can have their own consistent identity and personality in the computer-generated world. And since the interface is the room itself, guests can interact not only with the computer-generated world, but with each other as well. Bar code technology provides a virtually unlimited series of low-maintenance sensing devices (constrained only by available physical space), mapping every square inch of the room's surface into the virtual realm of the computer. Both sound and image are highly spatial. Stereoscopic images are produced by a pair of video projectors, and localized sounds emanating from each of the objects are reproduced using a quadrophonic system.

Bar Code Hotel is designed to accommodate any number of guests, up to the available number of bar code wands (which is dependent on the particular configuration installed). So far,the Hotel has handled between one and five guests at a time.

Guests can scan any bar code within reach at any time. Each bar code is labeled (verbally or graphically), letting the user know what action will result.

The Virtual World

The projected environment consists of a number of computer-generated objects, each one corresponding to a different guest. These objects are brought into being by scanning unique bar codes that are printed on white cubes that are dispersed throughout the room. Once brought into existence, objects exist as semi-autonomous agents that are only partially under the control of their human collaborators. They also respond to other objects, and to their environment. They emit a variety of sounds in the course of their actions and interactions. They have their own behaviors and personalities; they have their own life spans (on the order of a few minutes); they age and (eventually) die.

The objects in Bar Code Hotel are based on a variety of familiar and inanimate things from everyday experience: eyeglasses, hats, suitcases, paper clips, boots, and so on. None of them are based on living creatures; their status as characters (and as surrogates for the user) is tentative, and depends totally upon their movement and interaction. At times they can organize themselves into a sort of visual sentence, an unstable and incoherent rebus.

Objects can interact with each other in a variety of ways, ranging from friendly to devious to downright nasty. They can form and break alliances. Together they make up an anarchic but functioning ecosystem.

Depending on the behavior, personality and interactive "style", these objects can at various times be thought of in a number of different ways. An object can become an agent, a double, a tool, a costume, a ghost, a slave, a nemesis, a politician, a pawn, a relative, an alien. Perhaps the best analogy is that of an exuberant and misbehaving pet.

Each object develops different capabilities and characteristics, depending on factors like age, size and history. For instance, younger objects tend to respond quickly to bar code scans; as they age, they become more and more sluggish. Older objects begin to malfunction, flickering and short-circuiting. Finally, each object dies, entering briefly into an ghostly afterlife. (This process can be accelerated by scanning suicide.) After each object departs, a new object can be initiated.

Bar Code Commands

Each time a guest scans a bar code, contact is re-established between that guest and their object. However, between these moments of human contact, objects are on their own. This allows for a number of possible styles of interaction. Guests can choose to stay in constant touch with their object, scanning in directives almost continuously. Or they may decide to exert a more remote influence, watching to see what happens, occasionally offering a bit of "advice" to their object.

Bar codes can be scanned to modify objects' behaviors, movements and location. Objects can expand and contract; they can breathe, tremble, jitter or bounce. Certain bar code commands describe movement patterns, such as drift (move slowly while randomly changing direction), dodge (move quickly with sudden unpredictable changes) and wallflower (move into the nearest corner). Other bar code commands describe relations between two objects: chase (pursue nearest object), avoid (stay as far away as possible from all other objects), punch (collide with the nearest object) and merge (occupy the same space as the nearest object). Of course, the result of scanning any particular bar code will vary, based on all objects current behavior and location.

Many bar code commands cause temporary appendages to grow out of objects. These appendages amplify and define various behaviors. Particularly aggressive objects often grow spikes, for example.

Besides controlling objects, certain bar codes affect and modify the environment in which the objects exist. The point of view of the computer projection can be shifted. Settings can be switched between various rooms and landscapes. Brief earthquakes can be created (leaving all objects in a state of utter disorientation).

Narrative Logic

Since any bar code can be scanned at any time, the narrative logic of Bar Code Hotel is strictly dependent on the decisions and whims of its guests. It can be played like a game without rules, or like a musical ensemble. It can seem to be a slow and graceful dance, or a slapstick comedy. And because the activities of Bar Code Hotel are affected both by its changing guests and by the autonomous behaviors of its various objects, the potential exists for the manifestation of a vast number of unpredictable and dynamic scenarios.

Exhibition History


Technical Information

Technical Diagram
of Bar Code Hotel

Input from the bar code readers is transmitted via RS232 to a Silicon Graphics Onyx, equipped with Reality Engine II and Multi-Channel Option. This is the primary graphics platform for the piece. The runtime software for the piece was written in C using Silicon Graphics' Performer libraries. Objects were modeled with Alias Animator.The Multi-Channel Option on the Onyx is necessary to produce dual video outputs for stereoscopic image projection. Twin video projectors with linear polarizing filters are registered on a 10 by 15 foot silver-surface screen.

The audio component of the work runs on a NeXT Cube with an IRCAM Workstation(ISPW), and a Macintosh IIx with a SampleCell card. The Onyx triggers the NeXT via Ethernet, and the NeXT triggers the Mac via MIDI. Both the NeXT and Macintosh run Max software. Four channel audio output is produced by using a MIDI-controlled mixer, which feeds into dual amplifiers and then to a quadraphonic speaker system.

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All contents copyright (C) 1995 Perry Hoberman
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Revised: 2-20-95