Chromatophoric Architecture

Contents
For Nicole
Martina Eberle: Foreword 7
1 Introduction
Prologue 12
Chromatophoric Architecture 16
Presentation of Various Voxel Façade Systems 28
2 Implications for Architecture
A Discussion of Works in the Field of Enquiry 42
The Significance of Voxel Façades for Architecture 60
3 Projects
Introduction to the Projects 82
From Moving Image to Moving Surface 84
Simon Schubiger-Banz: Control Units and
Interacting with Voxel Façades 90
Alexia Maddox and M. Hank Haeusler: Social Form 100
4 Appendix
Glossary and Abbreviations 104
Acknowledgments 107
Biographies 108

Presentation of Various Voxel Façade Systems
An LED-based static volume 3D display is built on the principle of arranging
LEDs in a 3D matrix with the possibility of switching each LED on and off
individually. The ways in which this basic principle is implemented in technical
systems, however, varies from design to design. The following list presents
selected design solutions in chronological order, providing an overview of
their evolution. Further below, indoor and outdoor applications are presented,
connecting these systems with specific design solutions.
left: LED Cube by Stephen Boyer, claimed to be the first 3D display system
right: Close-up view of 3D display cube v3 by James Clar
One of the first people to explore the use of LEDs to display objects in 3D is
Stephen W. Boyer. According to his homepage 1 , he handed in a patent for a
“Light Art Structure” on May 22, 2001. The system has been described as
an ornamental design for a light art structure using 125 LEDs embedded into
acrylic tubes. It was first presented in an exhibition in Chicago in 1999.
The 3D display cube v1 was the starting point of a series of works using 3D
displays by New York-based artist James Clar in 2002. In the first version—
produced in collaboration with Todd Holoubek, Cindy Jeffers, and Danielle
Lee—100 LEDs were imbedded into clear acrylic planes. In total, ten planes with
100 LEDs each made up a cube with 1000 voxels, increasing the number of
pixels compared to the previous version by Stephen W. Boyer tenfold.
Following this first prototype, the 3D display cube v3 in 2003 2 was a handmade
version with freestanding LEDs that were not embedded in an acrylic plane.
Each of the 1,000 LEDs could be controlled individually with a refreshing rate
of sixty frames per second via a serial input. Not only the hardware but also the
media content the system was to display played a role in its design right from
the beginning. The 3D display cube could be connected to a camera or sound
system via a serial input to allow for video and/or sound transmission.
28 Presentation of Various Voxel Façade Systems

left: Cubatron at Burning Man Festival, 2004, another system working as a 3D display
right: Big Round Cubatron at Burning Man Festival 2006
left: Big Round Cubatron at Burning Man Festival 2006. The detail shows that the system is rather
fragile and is used more as an artistic installation instead of as an integral element of architecture.
right: Detail of the Installation in Delft. As can be deduced from the picture, one of the system’s
disadvantages is the time-consuming replacement of single parts.
However, this kind of system is still far from being used in an unprotected
outdoor environment as it is quite fragile. In 2006, the Cubatron’s successor,
called “The Big Round Cubatron“ (BRC), claimed to be the world’s largest 3D
full-color dynamic light sculpture. It consists of an array of light points with a total
dimension of over twelve meters in diameter and three meters in height. A series
of spokes —twenty-eight in number—each of which is twenty-four lights wide and
nine lights high make up the system. Each light is independently controllable to
display any color and brightness and the entire display can be updated fifty times
per second. There are 6,048 voxels in total (28 x 24 x 9), each containing a red,
blue and green LED to allow for a color display, bringing the total number of
LEDs to 18,144.
Students of electrical engineering at the Delft University of Technology in the
Netherlands created a 3D display in May 2006. 4 The display consisted of 8,000
suspended ping-pong balls that each contained a red LED light. It was able to
play the games of 3D snake, 3D ping pong, and 3D duck hunt, and was also
able to display mobile phone text messages and simple animations. The display
used four kilometers of copper wire, three kilos of solder, a couple of hundred
meters of aluminum brackets and eight printed circuit boards.
It can be said that the main aim of this system was to prove its technical
workability not necessarily its practicality. The voxel system used in the
installation by the students of Delft University of Technology placed LEDs
into ping-pong balls to create a bigger light point. One of the main drawbacks
of the system is its fragility. The wires used for connecting the LEDs are also
used to provide physical stability to the structure, supported by metal frames.
This may work well for an installation where physical disturbances can be
kept to a minimum. However, it would prove difficult to run it successfully in
an environment where, say, vandalism may occur, or outdoors. Wind loads,
adverse weather conditions, and other environmental factors would probably
harm the system as well. The second problem is the above-mentioned issue
of the repair and replacement of single components. Replacing a single LED
in the center of the cube could become quite difficult.
Up to this point, the only systems that have been discussed were either
32 Presentation of Various Voxel Façade Systems 33

The 3D Installation in Delft, a system built by electrical engineering students from the Delft University
of Technology, the Netherlands
prototypes, installations, or commercially unavailable—with the exception of
the 3D display cube v3 and v4.
In September 2006, the ETH Zurich inaugurated NOVA, a three-dimensional
color display, at Zurich Central Station for its 150th anniversary. It was
developed by the ETH Zurich and realized with the support of private
companies, institutions and foundations. 5 The installation has an impressive
volume of twenty-five cubic meters, measuring 5 x 5 x 1 meters, suspended
nine meters above the ground. For a display of this size 25,000 voxels with
300,000 individual LEDs were necessary. Custom-made software allows for
the display of media content such as statistical data, rendered images, or
videos with a refreshing rate of twenty-five images per second; a rate which
is often used for movies.
NOVA connects each voxel with a thin black “stick” that contains the wiring
and also functions as a structural element. Due to this structural arrangement,
the installation must hang from a ceiling to work. NOVA has also been
designed and developed for an indoor environment.
right: NOVA system
located at Zurich Central
Station, Switzerland
34 Presentation of Various Voxel Façade Systems 35

A prototype solution for an outdoor voxel façade system was researched
and developed by the author during PhD research conducted at the Spatial
Information Architecture Laboratory (SIAL)/RMIT University in Melbourne,
Australia from 2004–2008. 6 The focus here was on designing a prototype
specially suited for outdoor architectural applications, where concerns such as
vandalism and the weather actively informed the design process. Unlike previous
systems, it is a single element, the LED stick—including a base element and
voxels that are embedded in a clear acrylic tube—to be assembled horizontally
on the substructure of a façade. By embedding voxels in a clear acrylic tube, the
system is able to resist weather conditions, be waterproof, as well as impactresistant.
The voxel façade would be assembled from a certain number of LED
sticks, allowing for easy replacement of faulty elements by replacing an LED stick
as a whole. Creating a voxel façade using single modules also provides the option
to have openings in a voxel façade such as for doors or windows. Furthermore,
cost control is improved since the number of LED sticks can be easily increased
or decreased per running meter, meeting requirements more accurately and
without creating waste.
In all the systems mentioned above, data is represented in a 3D or 4D mode
by using a matrix of voxels, a volume element representing a value on a regular
grid in 3D space. Each voxel is represented by a sphere using an LED-based
static 3D display system. The light of each of these LEDs produces an intangible
surface made up of light points. This intangible surface can be created by
placing a number of RGB LEDs equidistantly next to each other to create a 3D
grid or zone in which media content can be displayed. Using this arrangement,
a constant resolution can be achieved in all three directions. Images can be
displayed in X, Y, and Z planes and, more importantly, as 3D objects. In this way,
a 3D object, surface, form, or image defined by light points can be realized within
the zone. A voxel façade is thus able to display the dimension of time within a
spatial construct. The dimension of time can be brought to function by everchanging
sets of data that define the movement within the zone set by the voxel
arrangement.
Having treated the history of LED-based static volume 3D displays and shown
that light points can very well define space, I now discuss the merits and
Rendering of an
array of LED sticks
36 Presentation of Various Voxel Façade Systems 37

Artist impression of a cube covered with Spatial Dynamic Media System

SDMS (Spatial Dynamic Media System) single element LED stick prototype

2
Implications for
Architecture
A Discussion of Works in the Field of Enquiry
Detail of The Source by Greyworld, 2004
For a discussion of Chromatophoric Architecture in the contemporary built
environment, various examples of existing buildings/installations that demonstrate
how space, shape, image, and form have been transformed in architecture
through public participation and changes in environmental perception are
presented here. The presentation of the following five projects focuses on how
they construct a “reciprocal environment modification” and the methods they use
to do so.
The five projects are as follows:
A group of London-based artists, Greyworld, who have produced a number of
pieces of interactive architecture, have created The Source (London, England,
2004) that transmits information through moving arrays of 3D illuminated spheres
within an eight story-high kinetic sculpture. Installed in the main atrium of the new
London Stock Exchange building in July 2004, information on trade activity of the
London stock market is relayed by the sculpture’s constantly changing shape.
In a cube of 9 x 9 x 9 meters, a total of 729 spheres are suspended from
44 A Discussion of Works in the Field of Enquiry

The Altar of Zeus from Pergamon, c. 164–156 BC
extent in space allows the viewer to move along with it and always see parts of
it in a different perspective. A good example for this is the Altar of Zeus from
Pergamon from circa 164–156 BC, which is housed at the Pergamon Museum
in Berlin. The frieze is composed of a sequence of isolated groups and figures,
each telling a self-contained story composed in a tightly-knit manner.
The possibilities of a voxel façade allow the experience of the spatiality of a zone
depending on the different positions of the beholder in relation to the surface. It
creates a three-dimensional zone similar to a relief. As such, it can be said that
the contemporary counterpart to the ancient Greco-Roman reliefs is the LED-
based static volume 3D display that creates an interactive amalgam of form and
image within an activated space. We may call the latter a dynamic relief.
At the same time, there are also obvious differences between reliefs made
from marble or stone and an LED-defined zone of a static volume 3D display.
Perhaps the most important is the fact that a traditional relief utilizes tangible
architectural building materials whereas a modern dynamic relief uses the
medium of light points. This brings us to the question of whether this form of
architecture therefore is a virtual one.
An LED-based static volume 3D display creates virtual space in the sense of
64 The Significance of Voxel Façades for Architecture 65

The structure of the building is placed on piles in the water and a tensegrity
system of rectilinear struts and diagonal rods cantilevers out over the lake.
Ramps and walkways wind through the tensegrity system. 10
Again, Designboom mentions that high-grade steel jets spray high-pressure
water through tiny apertures that are only 120 microns across. The water then
sprays onto fine needle points directly above the apertures at a pressure of
eighty bars, where it is atomized into innumerable tiny droplets four to ten microns
in diameter. The droplets are so small that most of them remain suspended in
the air. If sufficient jets are installed—creating a specific volume—they saturate
the air with moisture and create the effect of mist appropriately named a blur in
this case.
The public can approach the blur via a bridge. The 122-meter-long bridge drops
visitors off at the center of the fog mass onto a large open-air platform. Visual
and acoustic references are drowned out while approaching the fog, leaving
only a visual “white-out” and the ”white noise” of pulsating water nozzles. The
original concept incorporated the idea of a questionnaire/character profile that
would be filled out by visitors prior to entering after which they would receive a
“braincoat” (smart raincoat). According to www.arcspace.com, this “braincoat”
would not only be used as a protection from the wet environment, but also as an
electronic store for the unique personality data of each visitor for the purpose
of communicating with the cloud’s computer network. As such, tracking visitors
through their movement around the system and a comparison of their character
profiles becomes possible. However, to the great dismay of the architects,
“braincoats,” the integrated media installation, was canceled during the design
process. In the installation that was realized, visitors could walk up to the Angel
Bar at the summit. The final ascent to the Angel Bar resembles the sensation of
flying in an airplane as one pierces through the cloud layer to reach clear skies.
At night, the fog functioned like a dynamic, thick video screen. 11
Blur Building by Diller Scofidio + Renfro, 2002. View towards building
What conclusions can we draw from these three projects?
The first two projects, The Source and Aegis Hyposurface, both alter their
spatial appearances through tangible surfaces made out of spheres or metal
plates. The Blur building offers a different approach to how space could be
altered, in this case with “mist” as a building material. The three projects
demonstrate that an alteration of space is possible by an interaction between
51

Image sequence on surface as the viewer moves from center further to one side
The Blur Building allows an alteration of form, though it is not predictable with
certainty in which direction the building would move and it is also not knowable
how the building looked before. Similarly, the Aegis Hyposurface only allows a
display of the form of the surface at one moment in the present with no reference
to the past or future of the surface form.
Another new term within Chromatophoric Architecture, privileged perspectives, is
best explained by means of two examples. Though, both examples are taken from
an art context, privileged perspectives can also be found in architecture.
The work of the French photographer Georges Rousses shows how privileged
perspectives are articulated in contemporary works of art.
Rousses’ photographic work translates the techniques of anamorphosis from
a 2D drawing to 3D space. The technique used is a combination of projection,
painting and photography. He first projects an image, such as a circle, onto
the walls of a hall or corner of a room. Due to the position of the projector, for
instance in a corner, the image is projected with a certain degree of distortion.
Rousses then copies this image by painting it onto the wall. As a last step, he
positions the camera at exactly the same point where the projector used to be
and photographs the painting. Through this technique he achieves two effects:
1) when looking at the photographed image the beholder gets the impression
that someone has painted on top of the photograph and 2) when walking
through the space of the installation the beholder will only understand and
experience the anamorphic effect when in the position where the projector used
to be.
Another example for a privileged perspective in art would be the sixteenth century
painting The Ambassadors (1533), by Hans Holbein the Younger, which is now
exhibited in the National Gallery in London (p. 75). The painting shows a distorted
skull in the foreground. The distortion corrects itself completely when the painting
and the skull are seen from an angle to the right of the center (p. 74).
Both examples work with anamorphosis, which is, according to Daily Cognition,
distorted projections or perspectives requiring the viewer to use special viewing
devices or to occupy a specific vantage point to reconstitute the image. 10 This is
what a voxel façade does too.
72 The Significance of Voxel Façades for Architecture 73

Surface view 1, generated from test image shown on previous page
Image from cloud movie clip that functioned as a base for the translation of a moving image into a
moving surface
converts into numerical kilobits of information relating to the size and color of the
image in greyscale. It then becomes possible to save the image as a ‘text image’
in .txt file format. A 5 x 5 pixel image would thus be translated into twenty-five
different numbers representing the five rows and five columns of the image in
greyscale. Greyscale has pixel values ranging from 0 to 255, with 0 being the
darkest (i.e. black) and 255 the lightest (i.e. white). As such, the numbers in
the cells can vary between 0 and 255.
Some of the early studies translated a black and white image onto a voxel
surface. The image shown on page 83 has been altered from its original
resolution and color to an 8 bit image with a resolution of 20 pixels in height
and 26 pixels in width. Through the use of a script, based on the premises
explained above, the image could then be translated into a surface where each
layer can be given a different color.
Based on these premises, a randomly chosen movie clip was translated into
individual images. Each of these images has then been altered into a greyscale
8-bit image and then into a text image as described earlier.
To show how the resulting image could look like, a movie showing clouds moving
across a blue sky in time lapse mode has been chosen as an example. Each
frame of the movie has been altered into a greyscale 8-bit image and was further
processed to achieve a voxel as described above.
The image shown is a visualization in an Open Scene Graph environment as
a translation of the cloud movie clip suitable to be presented in a voxel façade
environment. The project which is presently in further development allows for the
display of life content in real-time in a voxel façade environment. The aim is to film
the movement of people in front of the voxel façade. Their movement results in
a change of color information in each pixel and at each frame, creating a moving
surface and making possible a new relation between the movement of a body and
the movement of space.
The project demonstrated that it is possible to provide future artists from a film or
image processing background with a new tool that would allow them to explore
the potential of voxel façades. Chromatophoric Architecture is of interest to many
84 From Moving Image to Moving Surface 85

Physical configuration editing with NOVA Studio
Due to the flexible hardware configuration options of the NOVA, content is
closely related to an actual physical configuration. For that purpose, physical
configuration management is also handled by the NOVA software. Inside NOVA
Studio, a so-called voxelizer creates physical configurations from existing CAD
models (see image above), which can be used for pre-visualizing content as well
as outline detailed configuration and mounting instructions.
Procedural Content
NOVA voxel display in 2D mode
Whereas offline content creation targets more the classic video-oriented user
base, procedural content attracts mainly new media artists. Procedural or
generative art is based on algorithms generally expressed in a programming
language that manifests itself in the physical world through generated sound,
images etc. For voxel displays, the translation from abstract algorithms to the real
world means rendering frames for a specific physical configuration in real time.
For that purpose, we provide the creation of hardware configurations through
92 Simon Schubiger-Banz: Control Units and Interacting with Voxel Façades 93

Sequence of images based on cloud movie and then translated into surface movies
researchers who are exploring the possibility of altering architecture through
film rather than conventionally representing architecture in film. As such, a new
way of looking at movie narratives is opened up.
The experiments have shown that it is possible to weave together architecture
and images creating a result which closely resembles the original image but
which at the same time is more than a simple 3D representation of the image.
The translation of movement in a film forms the focus of movie making using
Chromatophoric Architecture. Two-dimensional forms are not literally translated
into a 3D form. To give an example, the image of a person depicted in a 2D movie
will not be directly translated into three dimensions. Rather, the color information
stored in the 2D image of the person is used to construct an abstracted and
pictorially entirely different 3D image of the 2D object, creating a movement
when the color information of the 2D pixels change.
Detailed view of surface
86 From Moving Image to Moving Surface

Social Form
Alexia Maddox and M. Hank Haeusler
The 3D animation of social data—for instance what people do, how they come
together, and how groups of people behave across physical and virtual space—
represents a new wave of data animation displaying social sentience by means
of media façades. In this chapter, various projects that serve as examples are
discussed. The focus is on the application of media content onto voxel façades in
the form of social data. The collaborative research between Dr. M. Hank Haeusler
and Alexia Maddox aims to integrate social content into a visual media system
that animates information in three dimensions. The social content in the case
study under discussion in this chapter is based on social inquiry of modeling a
spatially distributed interest network. The illustrated case of a group of people
interested in reptiles and amphibians serves as a good example of how media
content functions in a social context in terms of the application of data onto a
voxel façade.
The aim of the collaborative research between Alexia Maddox and Dr Haeusler is
to create an interactive prototype to explore the process, the hardware, and the
display elements needed for transforming social content into a spatial display of
social form. This objective relates to the combined interests of the collaborators in
customizing the space created when social data or media content is transformed
into three-dimensional media space by means of a voxel display. The emphasis is
on the surface texture of the generated form, providing new aesthetic results as
well as producing visual analyses of media content.
The media content consists of sociological data generated by a quantitative
survey of the global herpetological community conducted by Maddox from July to
September 2006 as part of her PhD thesis. The population that was researched
provides unique access and insight into a tech-savvy social world that uses all
of the same gadgets and processes we do in our everyday lives, such as online
Visualisation of a social form
98 Alexia Maddox and M. Hank Haeusler: Social Form 99