Extreme 3D
by Dan Collins,
Associate Professor of Art, Arizona State University
The virtual space of the computer is allowing artists, designers, and engineers to
pre-visualize form, pursue sophisticated formal innovations, to design at
heretofore unmanageable scales with technical accuracy, and to interact with
objects impossible to create with the human hand. But there are a host of new
3D input and output methods available that are still barely on the CRT of most of
the 3D community. These new techniques can serve to broaden the palette of
the “digital sculptor” or anyone interested in capturing exotic data and translating
it into tangible 3D objects. Welcome to the world of “extreme 3D.”
Three domains must be understood and mastered by the extreme 3D artist: Data
Acquisition (input technologies); Computer Aided Design, modeling, and
visualization (CAD), and Computer-Aided Manufacturing (CAM).
3D Data Capture: From Microscopes to Satellites
The first domain, data capture, covers a wide array of systems operating at a full
spectrum of scales. Virtually anything that can be mapped in 3D can be rendered
as a digital model.
Extremely tiny objects--e.g., blood cells, crystalline structures, larger molecules
at nano scales--can be rendered as three-dimensional models using tools such
as a Scanning Probe Microscope. Objects are measured in nanometers--units a
billionth of a meter long. Slightly cruder in its resolution is the Confocal
Microscope which is adept at rendering three-dimensional objects at micro
scales. Models are measured in microns--units a millionth of a meter long.
At larger scales, objects several millimeters across can be digitized with manual
probes or optically scanned using 3D laser scanners. Depending on the lens
configuration, resolutions as fine as .125 mm can be achieved. Whole body
scanners—such as has been developed by Cyberware of Monterey California-record a million data points spaced at 3 mm intervals. Camera based systems
such as 3Q’s are configured to digitally capture the human form in 3-D using a
non-laser technique known as Digital Surface Photogrammetry (DSP).This
approach employs projecting a random light pattern on the subject and capturing
the surface contours and color information with precisely synchronized digital
cameras set at various angles. Gamers can get their “skins” for the price of a
good haircut.
Medical diagnostic technologies such as MRI, CT scanners, and 3D Ultrasound
give three-dimensional representations of internal morphology. A company
called AmeriScan is providing state of the art CT scans in shopping malls for a
fraction of the cost of a typical hospital visit. These technologies enable a new
kind of "figurative sculpture" that reveals both internal and external anatomy.
Long range scanners from companies like Mensi and Cyra produce hi resolution
3D models of larger objects such as architectural facades, geological features, or
archaeological sites. Using lasers and optical triangulation, these systems can
acquire data up to 100 meters from the source object at accuracies up to .21
mm.
At very large scales, terrestial maps or extraterrestrial planetary surface data are
delivered by satellites equipped with systems such as Synthetic Aperture Radar.
Satellite data in the form of DEMs (Digital Elevation Models) are freely available
from the USGS. DEMs consist of a sampled array of elevations for a number of
ground positions at regularly spaced intervals. These can be translated into
usable 3D models using conventional 3D modeling packages such as
Rhinocerous or 3D Studio Max.
Computer Visualization: Modeling the Data
Much as the drawings of Leonardo, Vesalius, and Alberti achieved a synthesis
among techniques of observation, systems of measurement, and the pure
pleasure of representational drawing and painting, recent work in computer
visualization provides a link between contemporary aesthetics and science. In
many respects, computer visualization is where a quantifiable description of the
world--the traditional domain of the physical and life sciences--finds new
expression and meaning in enhanced methods of representation--the traditional
domain of the arts and humanities.
"Computer visualization" is an area familiar to anyone who has struggled with the
learning curves typical of 3D modeling packages. At its most arcane, the task of
translating quantifiable information into pictures falls to mathematicians,
programmers, and software engineers trained in Computer Aided Geometric
Design (CAGD) and Computer Graphics. Most sculptors do not have the
requisite technical skills to develop the algorithms or programs that are
necessary for translating abstract spatial concepts into 3D models on the screen.
However, artists comfortable with working in three dimensions will find that their
skills at visualization, "imaging", and conceptualization are highly valued in
technical circles. As one becomes more adept at the protocols of a 3D digital
universe, a healthy appreciation of the complexity, logic--and especially the
elegance--of software and hardware design will grow.
We are seeing increasing numbers of successful collaborations between
individuals with technical competencies and those with an eye for the aesthetic or
the conceptual. Major conferences in computer graphics such as SIGGRAPH
highlight the latest breakthroughs in art, industry, entertainment, and theoretical
computation. The entertainment industry drives much of the technology and
provides opportunities, challenges, and applications for the development of
complex algorithms and new programming protocols. The special effects
wizardry achieved by Steve Jobs's company, Pixar, and the legendary work of
George Lucas and his company Industrial Light and are just two examples of
companies that are built on the premise of collaborative enterprise between
technologists and artists. Apart from the kinds of spectacles possible with the
deep pockets of the entertainment business, there are some unique, innovative
projects that bring together the best the arts and sciences have to offer. The
CAVE project (Cave Automatic Virtual Environment) at the Electronic
Visualization Laboratory at the University of Illinois at Chicago is perhaps one of
the more innovative examples of collaborative enterprise integrating high end
graphics into an immersive 3D audio/video experience. Viewers wear special
glasses utilizing "shuttering" technology (LCD stereo shutter glasses are used to
separate the alternating video fields being received by the eyes), and move
through a space "guided" by a leader wearing a full VR headset. The correct
perspective and stereo projects of the environment are updated, and the image
moves with and surrounds the viewer. Content explored has included everything
from the visualization of natural phenomena to scientific data to "fine art"
immersive environments.
Many related areas converge in computer visualization. Computer graphics,
scientific visualization of all kinds, 3D Modeling, 3D Archive/Database
development, 3D Pattern Recognition (requiring artificial intelligence expertise)
are just some of the areas of interest to the digital sculptor.
A set of tools that can accommodate the diversity of data generated by the range
of data input devices enumerated above is essential. In the PRISM lab--a
research unit devoted to visualizaton and prototyping at Arizona State University-data gathered from machines as diverse as Scanning Electron Microscopes,
MRI machines, and 3D laser scanners has been successfully translated into solid
models. We are currently using portable 3D laser scanners in the development of
a data base of anthropological artifacts ranging from Anasazi pottery, to lithics, to
hominid bones.
Form Realization: 3D Printing and Rapid Prototyping
At the heart of the process of digital sculpture is the desire to translate threedimensional objects designed in the virtual space of the computer into actual
three-dimensions--a process generally known in industry as "rapid prototyping."
Rapid computer-based prototyping--more precisely called "layered
manufacturing"--is a relatively new field that is gaining increasing acceptance in
fields as diverse as medicine, aerospace, industrial engineering, and sculpture.
Complex three-dimensional objects such as human prostheses, molded tooling,
or aerospace parts are produced by linking Computer Aided Design (CAD)
products with various rapid prototyping (RP) systems. It is also an ideal tool for
concept modeling as RP systems can provide CAD-equipped design engineers
(and digital sculptors!) with a physical model of a proposed design that they can
touch, examine in detail, and ship to others for inspection and review.
There are numerous automated devices that can translate 3D CAD models into
tangible form. Most common are the Computer numerically controlled (CNC)
machines that have been in service since the 1970s. CNC milling enables
computer controlled cutting on multiple axes in a variety of materials. Earlier
electromechanical machines--both analog and digital--capable of cutting
relatively complex solids were introduced just after World War II. Other machines
regularly used in heavy industry include computer controlled plasma and laser
cutters, electro discharge machining (EDM) systems, automated hi-pressure
waterjet cutters, and various sand and glass bead blasting technologies, to name
a few. Most of these tools have unique control protocols that do not port easily
from one machine to another.
An entirely new category of manufacturing processes are classified under the
rubric of "layered object manufacturing." All of these new systems--irrespective of
the methods with which the final part is made--require "solid models" that are
subsequently "sliced" (digitally) into multiple horizontal "layers" that can be
produced in sequence by a given process. Some machines cut individual sheets
of paper (with razor blades or lasers); others deposit thin semi-liquid threads of
wax or plastic; still others use lasers to harden liquid resins, fuse synthetic
"flours", or, in the most exotic processes, cause precise chemical reactions to
occur at given points within a gas-filled chamber (only at very small scales).
Within the field of layered object manufacturing there is a rapidly growing number
of competing technologies ranging from small desk-top "3D printers" and
cutter/plotter devices to room-sized "rapid prototyping centers." Each technology
has its advantages and disadvantages. As might be expected, the desk-top units
are relatively inexpensive. A computer aided plotter device that cuts individual
sheets of adhesive backed craft paper machine can be purchased for less than
$7500.00. At the other extreme, a laser "sintering" (fusing) machine can cost
over half a million dollars. In these high end machines, the hard-copy output is
remarkable for both the fineness of surface detail and their robust structural
integrity. Advances in the range of materials available for prototyping permit
particle sizes of as small as 40 microns (e.g. DTM's"True Form") which can be
fused for fine feature definitions down to .004 inches resolution. Middle range
desktop machines such as the Stratasys/Genisys thermoplastic extrusion system
($50-60,000.00) can achieve resolutions of .020 inches. A short list of the
companies that manufacture RP devices include the following: 3D Systems
pioneered the so-called "stereolithographic" systems (SLA) in which a bath of
photosensitive resin is hardened by a laser. Stratasys specializes in a process
known as Fused Deposition Modeling which involves the extrusion and precise
layup of a continuous thread of hot thermoplastic. They have recently introduced
a sophisticated FDM machine for under $30,000. Z-Corp’s technology is built on
an MIT patent for “3D printing” which bypasses the need for support structures by
building the object in a container of starch-based powder. While it is like other
“layered manufacturing processes” in that it utilizes an .stl file format, it uses an
“inkjet” type process to harden the layers of powdered starch/cellulose. Z-Corp
recently introduced both a full RGB color machine (millions of colors) and a
machine with a much larger build envelope (20" x 24" x 16").
Because of the significant cost savings that can be achieved by shortening the
production cycle in industry, there is substantial interest in all kinds of rapid
prototyping. Many of the initial problems associated with rapid prototyping-toxicity, lack of durability, problems in translation to metal or cold casting
methods--have been solved. A handful of companies have already perfected
methods for directly producing production level tooling (for injection molding
machines, in particular) using RP technologies.
Goals for Research and Teaching
What does the future hold? On a technical level, new machines are on the
boards that will expand the capabilities of Rapid Prototyping technology into a
broader range of scales and materials. Functional prototypes in materials ranging
from hard steel to flexible rubbers are already possible. Can organic structures
be far behind? Research on a theoretical level is currently being conducted into
the next level of volumetric data storage. If a "pixel" (literally "picture element")
represents the base level unit for typical 2D representations, the new unit of
choice is the "voxel"--a neologism that combines the words "pixel" and "volume."
Systems are envisioned that would be tied to enhanced voxel data sets that allow
an operator to specify not only volumetric information, but material or physical
property characteristics. Imagine, for example, a knife blade created in a rapid
prototyping machine that would be able to be "custom crafted" to different
specified levels of flexibility and density..
In the area of Interdisciplinary Education, I am particularly excited about an
integrated approach to techniques of visualization and prototyping that could
serve as a vehicle for innovative teaching and a cross-disciplinary curriculum.
These technologies lend themselves readily to hands-on approaches and "active
learning." Further, as all design and output is part of an ever-expanding digital
record, the archiving of raw data and product will provide opportunities to pursue
collaborative research across disciplines and with other institutions. Ideally, a
critical discussion will ensue that looks closely at the formulation and
interpretation of data and physical prototypes derived from that data. The
theoretical (and legal) problems associated with digital imagery, virtual reality,
and simulation, and the context-dependent factors that issue from particular
methodological biases need to be explored by interdisciplinary thinkers not afraid
to draw from historical precedent, the "science" of fiction, and studies in the
humanities ranging from ethics, pscyhology, and education.
The demand for expertise in visualization, modeling, rapid-prototyping and
manufacturing is exceptionally strong right now in both the arts and sciences. It is
a growth sector for future generations of students. Access to equipment and
training programs that extend these new technologies to those communities and
constituencies who remain technologically impoverished are essential.
Conclusion
All of these new concepts and systems depend on the computer for its ability to
translate quantifiable data into visual information. Using systems that are
becoming increasingly accessible to the non-technologist by virtue of improved
graphical interfaces and hardware, artists can now move with impunity (if not
total freedom) in a domain heretofore dominated by computer scientists and
engineers. While it would be a mistake to suggest that a lay individual can move
easily into high end rapid prototyping, with ever improving GUI's and the ubiquity
of learning tools for 3D digital media, it can be argued that "digital sculpture" has
come of age. What about the rest of the culture?
Future individuals and communities may be distinguished by their ability to meet
the challenge of form-making with methods that are quick and responsive--that
meet the need for objects, abstract forms, or environments as they arise. New
technologies that utilize transparent interfaces, reduce technological restraints,
and encourage interative design processes and customized products have the
potential for changing our 3D environment and making it more user responsive.
Design and production by users-for users in real time, of course, depends on
models of design, manufacturing, distribution, and consumerism that are only just
beginning to take shape.
As with any new technology, the real challenge will be to not fetishize the
machines or their products as ends in themselves, but to focus on the quality of
the activities enabled by the technology. No one would dispute our status as
consummate tool designers and makers. The challenge is for all of us to become
better tool users.