March 1998 - Computer Graphics World
by Steve Nadis

From Bones to Clones

Let's face it: Packaging and transporting dinosaur skeletons is a tricky business. Even if you can find a suitably large container, how on Earth are you ever going to protect the irreplacable contents? By tossing in a few "peanuts" and slapping on a few "fragile" stickers?

Perhaps there's a better way, thanks to the advent of 3D digital scanning technology. The approach involves using laser scanning devices, among other means, to produce accurate digital models of objects that can be shipped electronically to reseachers all over the world. In this way, large numbers of people can simultaneously study facsimiles of rare, fragile specimens, without damaging the original object.

In a recent demonstration of this technology, two California companies-Scansite of San Anselmo and Dinometrics of San Francisco-have joined forces to construct a 3D digital model of "Sue," the Tyrannosaurus Rex skeleton that was sold to the Chicago Field Museum for $8.4 million. The team accomplished this by scanning individual bones of the T-Rex remains and feeding the information to a computer, which integrated the data to form a composite picture of the primeval beast. The group has also created a computerized rendering of Titanis-a six foot tall "killer bird" that could be found stalking the Florida countryside three million years ago-and is conducting the first digital research on this creature in concert with its discoverer, Robert Chandler of Georgia College and State University.

"Our goal is to put Jurassic Park technology into the hands of the researchers, not just the entertainment industry," says Dave Marrs, Dinometrics' founder and director. "An advantage of working with a computer is that you can easily test the posture of the animal, its anatomy, and the dynamics of movements-things that are very hard to do with reconstructed animals as large as dinosaurs."

It is possible to get close-up views of the scanned images that reveal details invisible to the naked eye. With a peak resolution of 0.125 millimeter (about five-thousanths of an inch), "we can observe minute hairline cracks and muscle insertion points in the bones," says Marrs. Such detail provides knowledge that offers a clearer picture of dinosaur anatomy.

"Obviously, the data can't be better than the original object," explains architect and Scansite co-founder David Bassett. "But this technology enables you to analyze specimens in ways that cannot be done with the naked eye." For instance, one can make "virtual cuts" to see cross section slices of bone simply by subtracting data that is not of interest. "That's easy to do on a computer," Bassett says. "Without a computer, in order to see a cross-section, you have to saw the specimen in half, which is something you normally can't do with a valueable fossil."

Once a database is created, moreover, it can be copied and shipped anywhere in the world for researchers to analyze and manipulate, adds Lisa Federici, who founded Scansite with Bassett.

Scansite employs two kinds of laser scanning devices, both made by Cyberware of Monterey, California. One machine scans continuously as it moves around the object. The other device remains stationary, taking a series of snapshots as the object moves around the around it. Digital profiles are made by shining low-power laser light on the object from numerous angles, while cameras or other detectors capture the object's color, shape, size and surface characteristics. After recording a series of profiles, Scansite's software then assembles the data into a 3D model. "Scanners are so accurate these days that you can literally get a 'digital clone' of the original object," Federici says.

The process has become much faster overall: It now takes just 17 seconds to scan a person. One of the breakthroughs stems from newly developed software that can merge separate files containing different views of an object in minutes to produce a single image.

A lot has changed from the user standpoint, as well. "A few years ago, most people didn't have the hardware or software to run 3D stuff," Bassett notes. "Now you can run 3D applications on a $3500.00 machine. Thousands of people with PCs or Macs can use our data, and they could even take it off the internet."

Scansite has worked with numerous museums in California to create "electronic archives" of artifacts ranging from human and animal remains to Indian baskets. "Every year, these artifacts are deteriorating from age, light, pollution, and dust," Federici says. "People are hoping to record them before we lose them altogether." In this way, museums can obtain "digital backups of the real things that can be used to make casts, even if the original is lost forever," Marrs adds. The information derived from scans can also be used to create "virtual museums" on the Web.