3D Scanner Designed To Scrutinize Works Of Michelangelo

MONTEREY, CA - January 6, 1999 - An ambitious effort is now underway to create the first authoritative 3D computer archive of Michelangelo's most famous sculptures. The Digital Michelangelo Project promises to make virtual copies of Michelangelo's statues available for appreciation and study around the world. It will set a new standard for the computer representation of three-dimensional physical objects. The project is led by Marc Levoy associate professor of computer science and electrical engineering at Stanford University. The project selected Cyberware (Monterey, CA) to build their principal 3D scanner. Cyberware designs, manufactures, and markets hardware and software for rapid, color, three-dimensional digitizing of both live subjects and inanimate objects.

As one would expect, entering a museum to scan objects of fine art presents challenging requirements. The scanner must view objects from many different angles to capture hidden surfaces, recording intricate details like chisel marks with high resolution. A safe standoff distance between the scanner and the sculptures is essential to protect the works and ease the concerns of curators. To capture the top portions of Michelangelo's David the system must operate reliably at heights of up to 7.6 meters (25'). The unique design of this custom scanning gantry allows the researchers to create 3D models that can be examined in greater detail and from angles impossible when the objects are viewed from the museum floor.

The Cyberware scanner sweeps a fine line of laser light across the sculpture's marble surface. The shape of this line as it curves across the unique features and chisel marks of the sculpture is captured by the scanner. This shape information is stored in computers as 3D coordinates for later processing into a surface model of the sculpture.

Other Cyberware 3D scanners based on this same technology have been used by the movie industry for years to create special effects for movies like Terminator 2 and Titanic.

Because the laser line is only 150 mm (6") long, the operators program the scanner to sweep it across the sculpture hundreds of times. Each part of the sculpture will be captured from many angles to assure that a complete and accurate model of the sculpture can be created. Because the sculptures have arms, legs and other features which can hide other portions of the sculpture from view, the scanner is designed to be able to work from above, below and all around.

The scanner's motion platform enables the scanner to view objects from a vantage point over 7 meters (23') high and includes pan, tilt and translate motions for the scan head that allow the operators to scan in otherwise difficult to reach areas. The motion system base is weighted to support its height and also has wheels that allow the operators to move the system around the object being scanned to collect data on different parts of the sculpture.

After scanning, the researchers will use software designed at Stanford University to assemble the individual scans into a complete 3D model.

The data collected by the scanner creates opportunities for researchers to learn more about working with very large data sets, alignment and merging methods and the application of texture maps.

Scanner Specifications

The custom scanning system designed and fabricated by Cyberware, at it's maximum height of 7.62 meters (25'), consists of a 2.44 meter (8') motorized vertical truss, two non-motorized truss extensions, a .91 meter (3') horizontal arm that translates vertically on the truss, a pan-tilt head that translates horizontally on the arm, and a scanner head. The entire assembly rests on a rolling base fitted with weights to insure stability. To further protect statues from contact with the gantry, there is also an elaborate system of automatic motion shutoffs and interlocks, and the entire scanner head and pan-tilt assembly are encased in foam rubber.

The scanner head consists of a laser, a range camera, a fiber-optic white light source, and a high-resolution color camera. The laser and range camera permit digitization of 3D points with a depth resolution of 100 microns (4 thousandths of an inch), a typical sampling pitch of 250 microns (10 thousandths of an inch), and a standoff of 112 cm (44"). This resolution is designed to accurately capture chisel marks. The calibrated working volume of the scan head is 2 meters (6.56') wide by 1.75 meters (5.74') high by .8 meters (2.62') deep. The light source and color camera is capable of measuring surface color with a pixel size of 125 microns (5 thousandths of an inch) over the same working volume.

About Cyberware

Cyberware, incorporated in 1982, designs, manufactures, and markets standard and custom hardware and software for rapid, color, three-dimensional digitizing. Pioneered by Cyberware, this laser-and-video-based technology takes only a few seconds to capture the shape and color of solid objects and live subjects for use on computers.

Cyberware's digitizing technology provides a unique capability for many different types of applications in art, animation, virtual reality, fashion, medicine, orthopedics, prosthetics, ergonomics, anthropology and industrial design. For more information about Cyberware and its products please visit our web site: http://www.cyberware.com.

See Also: Stanford's Digital Michelangelo Project Pages

Photographs available upon request.