OK, we all know how the virtual space of the computer gives 3D artists godlike power to create objects, avatars, animations, and interactive worlds. But there are a host of professional 3D input and output methods available that still barely register on the CRT screens of most of the 3D artist community. These techniques-some tried and true, others hot off the press-can serve to broaden the palette of animators, 3D Web designers, and digital sculptors.
A few pioneering artists have discovered the power of 3D capture devices operating at the full range of scales-from the nano to the planetary. Others are pushing the boundaries of CNC milling and rapid prototyping. Some examples: Using devices initially developed for reconstructive breast surgery, designers are creating characters for gaming. Downloading digital elevation models from the U.S. Geographic Service, Web artists are creating interactive sites with unprecedented topographic detail. Using new rapid prototyping systems, digital sculptors are creating tangible, full-color objects that bypass the products of traditional model shops and stretch conventional build envelopes. Welcome to the world of "extreme 3D art."
The extreme artist is a boundary pusher, a cross-disciplinary thinker, a cultural and technical tinkerer, and "hybridizer." These artists need to be savvy enough to talk their way into labs and studios that house advanced input and output technology. Or they need to build it themselves. While digital artists working in the 3D arena have mastered their modeling and animation software, many are out of the loop when it comes to bringing real-world data into their familiar virtual worlds, or, conversely, finding ways to push their designs out of the box and back into the real world.
Extreme artists need expertise in three domains: 3D data capture, computer-aided modeling, and computer-aided manufacturing. While computer artists are adept at modeling, those interested in the power of this new dimension must also be aware of the following 3D data capture (input) and manufacturing (output) technologies:
Real-world 3D data opens up unlimited possibilities for artists. Here's a range of techniques for capturing data ranging from the microscopic to the astronomic:
Microscopy: Extremely tiny objects-blood cells, crystalline structures, and molecules-can be rendered as 3D models using techniques such as scanning-probe or atomic-force mi croscopy. Such 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 3D objects in microns-units a millionth of a meter long. While these systems aren't going to be found at your nearest electronics outlet, it may be worth a trip to your local university to see what the engineers or bioscientists are doing with such instruments. They may be able to provide you with data sets that could be integrated into your artwork.
Laser scanning: At slightly larger scales, objects several millimeters across can be optically scanned using 3D laser scanners or digitized with manual probes. Depending on the lens configuration, resolutions as fine as 0.125mm can be achieved. Whole body scanners, such as those developed by Cyberware of Monterey, California, record a million data points spaced at latitudes 3mm apart.
Photogrammetry: Camera-based systems, like the ones from 3Q, are configured to digitally capture the human form in 3D using a non-laser technique known as digital surface photogrammetry. This approach involves 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. Since several of these systems are now located in shopping centers around the country, gamers can get their "skins" for the price of a good haircut.
Medical imaging: Diagnostic tools such as MRI, 3D ultrasound, and CT scanners give three-dimensional representations of internal morphology. A company called AmeriScan is providing state-of-the-art CT scans in upscale malls for a fraction of the cost of a typical hospital scan (around $900). These technologies enable a new kind of "figurative sculpture" that reveals both internal and external anatomy.
Long-range scanning: Systems from companies like Mensi and Cyra produce high resolution 3D models of large 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 of 0.21mm. Sample "point cloud" datasets can be downloaded from the Internet and translated into polygonal files using applications such as InnovMetric Software's PolyWorks or Raindrop Geomagic's Studio.
Satellite imaging: At very large scales, terrestrial maps and extraterrestrial planetary surface data are delivered by satellites capable of measuring not only latitude and longitude but altitude. Satellite data in the form of digital elevation models is freely available from the U.S. Geological Survey. These models consist of a sampled array of elevations for a number of ground positions at regularly spaced intervals. Many of the height maps derived from these systems are encoded as value scale images (where lighter values correspond to higher altitudes). These can be translated into usable 3D models using conventional 3D modeling packages such as Robert McNeel & Associates' Rhinoceros or Discreet's 3ds max. New York media artist John Klima has used digital elevation models in his notorious Web-based project, "The Great Game," which recorded troop movements during recent events in Afghanistan in relationship to a 3D terrain map of the region.
At the heart of the process of digital sculpture is the desire to translate 3D objects designed in the virtual space of the computer into physical objects. Processes ranging from computer numerically controlled (CNC) milling (a subtractive process) to rapid prototyping (an additive process) can be used for producing tangible prototypes and sculptures.
Advances in the range of materials available for prototyping permit particle sizes of as small as 40 microns, which can be fused for fine feature definitions at resolutions of 0.004 inches. A short list of the companies that offer RP devices include the following:
3D Systems pioneered the so-called "stereolithography apparatus" (SLA), in which a bath of photosensitive resin is hardened by a laser. Stratasys specializes in a process known as Fused Deposition Modeling (FDM), which involves the extrusion and precise layup of a continuous thread of hot thermoplastic. The company has recently introduced a sophisticated FDM machine for less than $30,000. Z-Corp's technology is built on an MIT patent for "3D printing." While it is like other layered manufacturing processes in that it utilizes an .STL file format, it uses an ink-jet-type process to harden the layers of powdered starch and cellulose. Z-Corp recently introduced a machine capable of producing millions of colors and one with a large build envelope of 20 by 24 by 16 inches.
Examples of works created with physical prototyping systems were recently part of the "Bit Streams" exhibition at the Whitney Museum of America Art in New York. Rapid prototyping tools were used by artists Robert Lazzarini and Michael Rees to create stunning sculptures generated from a combination of synthetically modeled data and 3D medical scanning (see December 1998, pg. 54).
Another artist taking advantage of digital manufacturing technology is Bill Kreysler, who has been working for years developing his own CNC machines for scaling up sculptural work. His best known projects include works for pop artist Claes Oldenberg as well as the MGM lion in Las Vegas. The lion was first modeled in clay, then digitized using 3D laser scanning. Tool paths generated from this original model were used to cut massive styrofoam blocks. Molds were taken from the scaled up foam model, and a bronze version of the lion-the second largest bronze sculpture in the world-was produced.
All 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 previously dominated by computer scientists and engineers.
We are already seeing hi-res 3D scanners located in malls. Can it be long before we see a "3D Kinkos" that will provide CNC or RP services for the general public? Of course, then it will no longer seem so extreme.
Dan Collins is associate professor of art at Arizona State University. He is also Chair of the Siggraph 2002 Studio, a hands-on environment that enables visitors to explore ideas in 2D, 3D, 4D, and n-dimensional media using the latest computer-based data-capture, modeling, and manufacturing devices. Siggraph 2002 will be held from July 21-26 in San Antonio, Texas. The author can be reached at firstname.lastname@example.org
The author created this sculpture, "Of More Than Two Minds," by rotating his head as it was laser scanned. He converted the point data to a solid model and created a wax model for a mold using a CNC milling machine.
Artists Robert Lazzarini and Michael Rees used rapid prototyping technology to create "Skull" and other sculptures from 3D medical scan data and synthetic models for the recent "Bit Streams" exhibition at the Whitney Museum of American Art.
Image courtesy of Pierogi Gallery, Brooklyn.