Creating Virtual 3-D Fossils
Laser Design Inc. RE-810 Laser Scanner

Suzanne Strait, Ph.D., specializes in vertebrate paleontology at Marshall University, located in Huntington, West Virginia. She became interested in scanning technologies while writing her thesis on the comparative anatomy of fossil mammal teeth. She first used an electron microscope to make 2-D scans of her specimens, but that time-consuming method didn’t provide the three-dimensional data necessary for researchers to manipulate the objects as 3-D models or take realistic measurements for comparison and study.

Strait kept abreast on the development of scanning technologies, and when she heard about 3-D laser scanning, she knew that it would be ideal for her purposes: faster, more accurate, noncontact, and in 3-D. She envisioned creating a web site as a virtual museum where researchers could view fossils in 3-D and download functions so that they could manipulate, measure, and compare them. An online 3-D resource would be a valuable tool for researchers, giving them access to many objects without having to travel to remote locations.

In 2000, Strait’s project, funded by the National Science Foundation, purchased a RE-810 laser scanning system from Minneapolis-based Laser Design Inc., a supplier of 3-D laser scanning systems and services for more than 20 years. The RE-810 is a desktop 3-D scanning system that is well suited for scanning small, highly detailed objects. The system scans parts from all orientations using a rotary stage to automate the scanning process, making 3-D image generation quick and simple.

The specimens are laser scanned and documented in PaleoView3D ( http://paleoview3d.marshall.edu), an online database/museum. The project also gives students an opportunity to scan and catalog specimens, which exposes them to modern field methods and high-end, state-of-the-art technology.

When Strait and her students began scanning fossils in 2000 on the Surveyor laser scanner, the system used Laser Design’s proprietary, UNIX-based software, but it was soon updated with Laser Design’s Surveyor Scan Control (SSC), a Windows version of the software that features enhanced functionality and ease of use. Using SSC, scanning and modeling processes became much easier for the students. SSC controls the laser scanner’s motions, manages the laser probe settings, and contains advanced automation features.

Because the laser scanning system projects a line of laser light onto surfaces while cameras continuously triangulate the changing distance and profile of the laser line as it sweeps along, the problem of missing data on an irregularly shaped surface is eliminated, and the object can be exactly replicated digitally without the need for templates or fixtures.

The Surveyor system’s laser, a high-accuracy RPS-120 probe with a high-scan density, is ideal for small and medium-sized specimens with fine detail features. “The resolution level of the probe is very good,” says Strait. “It produces a dense point cloud of coordinates so our measurement data is very accurate.

“Bone groups, such as a jawbone with teeth, are more challenging to scan and require multiple scans to gather enough data to create an accurate 3-D model,” she continues. “Most of the fossils are tiny, less than 1 mm, and have lots of undercuts.” Scanning free-form detailed shapes, however, is noncontact laser scanning’s forte, and the student operators easily master scanning techniques. Scanning from several orientations can be completed in less than an hour. After scanning, the data are converted into surface models, or reverse- engineered, using Raindrop Geomagic Studio 7.0, which can take another few hours.

The PaleoView3D interactive web site details the technical aspects of the laser scanning, such as the number of scans performed, the number of coordinate data points, and linear spacing of the scan lines. The surface models are high-resolution images that can be viewed in 3-D, magnified, and rotated. Simple measurements of each model can be made on the web site using a point-and-click feature. Each image can also be downloaded as a data file so that more sophisticated 3-D measurements can be made using CAD, GIS, or 3-D measurement software.

“We have made amazing progress on the PaleoView3D database thus far,” says Strait. “We hope to be a leader in what will be an explosion of online databases, an innovation possible because of the advancements in the field 3-D laser scanning found in our Surveyor system from Laser Design.”

Laser Design Inc. RE-810 Laser Scanner

Benefits:

• Fast and accurate, reducing time-to- market
• Measures the entire surface of an object, improving inspection, verification, and reverse-engineering
• Reduces the discrepancy between the as-designed part and the as-built part
• Highly automated and noncontact, so there is no operator error or variation in operator technique

www.laserdesign.com