To make a 3-D model, a laser scanner bounces light off an object and collects the resulting topological cloud of points. To reproduce every nook and cranny, the scanner snaps overlapping images from all possible angles. A computer then sews together one large surface image and draws lines from one point to another to create a wire-frame model. High-resolution digital cameras add color and texture. When fully assembled, the models can be viewed, printed or manipulated.
These scans do more than pickle a memory in a database. With highly accurate measurements, archaeologists can find hidden passages or reveal ancient engineering tricks. Schoolkids can explore places they might otherwise never see. And when a site is destroyed, the scans can even be used to reconstruct what was there. That has already happened for one World Heritage Site, the Kasubi Tombs in Uganda. Built of wood in 1882, they were destroyed by fire in 2010 and rebuilt in 2014, based in large part on 3-D models made in 2009. More than 100 World Heritage Sites have been already preserved as 3-D models, and conservationists are racing to record as many more as possible, especially in the conflict-torn Middle East and northern Africa.
Conservationists around the world are emulating CyArk’s methods. To scan Mount Rushmore, the nonprofit provided people, expertise and some funding. The U.S. National Park Service added funding plus a technical climbing team to scan the presidents’ nostrils and underneath their eyebrows. A local engineering firm and university mining department consulted on the local geology. Historic Scotland, the Scottish National Heritage agency and the Digital Design Studio of the Glasgow School of Art collected data and deployed them as tools for visualizing and conserving the mountain.
Bounce: v. 反弹
Topological: adj. 地质学的、拓扑学的
Sew: v. 缝纫、装订
Pickle: v. 腌制
Emulate: v. 模仿