by Ann
What is 3D Laser Scanning?
3D laser scanning is a non-intrusive, non-destructive technology that can digitally capture real-world physical objects using a line of laser light directed on the surface. The 3D laser scanner emits a narrow eye-safe laser beam while two sensor cameras continuously sweep across the object rapidly and precisely recording millions of fine details and free-form shapes. While the laser moves around the surface of the object, the data gathered from the object appears as millions of points creating “point clouds” on the computer which captures the physical object’s exact size and shape. The color of each point indicates the intensity of the return signal to the laser scanner. After creating the point cloud files, the data is then registered and merged to form a digital three-dimensional representation that can be viewed, printed, or manipulated. When measuring large objects such as historical and cultural heritage sites, the use of traditional measurement methods is impractical; however, a 3D laser scanning is fitted to the task of measuring and inspecting of complex and sizable surfaces.
See how Smithsonian’s “laser cowboys” use 3D laser scanning to document priceless and important objects.
How can 3D Laser Scanning be used?
The data sets gathered from the 3D laser scans can be used with 3D modeling to create realistic digital renderings of existing artifacts and sites. For instance, in May 2012, London’s Science Museum closed its famous Shipping Gallery which has been opened since 1963 and replaced the space with a new exhibit. The Shipping Gallery held thousands of objects including artifacts, detailed model ships, and dioramas, although the objects have been moved to storage, the space and the contents within has been virtually created with the assistance of the University College London and ScanLab, making the exhibition space available for future generations.
The scan used two Faro Photon 120 terrestrial laser scanners; these devices use rotating mirrors to record one million reflections per second in a 360-degree scan at sub-millimeter resolution. Over 200 scans were recorded, creating 2 billion precise cloud point measurements which were processed and then built into a 3D virtual model. The 3D model rendered allows new and future virtual visitors to view the 1,800 gallery objects in the same context (murals, cases, interiors, and architecture) it was held before the closing all the while digitally preserving the space and the objects.
Here you can view a video that has been created using only 10 percent of the data collected.
Learn about more projects implementing 3D laser scanning.
Why is 3D Laser Scanning important?
Employing 3D laser scanning preserves not only historic objects and locations but also provides a means for virtually exploring otherwise inaccessible environments, by mapping every millimeter of the surface and creating models from point cloud datasets. The non-intrusive nature of the technology provides a hands-off means of precisely analyzing, measuring, and cataloging of essential and fragile historical objects as excessive handling deteriorates the longevity of the objects and structures. 3D laser scanning also provides researchers a reference manual into how the artifacts and site changes over time, which will aid in their conservation efforts to protect and restore the historical nature of the structure. 3D scanning and imaging technology provides an invaluable resource towards the restoration, preservation, accessibility of at-risk and already lost sites for generations to come. Lastly, these efforts not only help ensure the protection of our global cultural heritage but also brings our culture to everyone, as the data is digitally available to any interested individual allowing them to access some of the most important artifacts and historic buildings and cities in the world.
For more general information concerning 3D laser scanning, consult:
LaserDesign. (n.d.). 3D Scanning Technology. Retrieved April 22, 2018 from https://www.laserdesign.com/what-is-3d-scanning.
LaserScanning-America. (n.d.). Historic Preservation. Retrieved April 22, 2018 from http://www.laserscanning-america.com/services/3d-imaging-historic-preservation/
SmartGeoMetrics. (n.d.). How 3D Laser Scanning and Modeling can Help Preserve Historic Structures. Retrieved April 22, 2018 from http://www.smartgeometrics.com/blog/historical-sites/how-3d-laser-scanning-and-modeling-can-help-preserve-historic-structures/
Szondy, D. (2013 August 31). Science Museum Preserves Shipping Gallery As Virtual Exhibit. New Atlas. Retrieved from https://newatlas.com/shipping-gallery-3d/28844/
Scientific Analysis & Conservation Tech 