The Sydney Opera House
, with its white-tiled, arched “shells” (or “sails”, depending on whom you happen to be speaking too), is a testament to creative genius and design. That, of course, is why it is inscribed as a UNESCO World Heritage Site
. Its iconic shape and style is also why construction of the shells took engineers 12 redesigns of the construction method over six years simply to find a way to create Utzon’s conception. The resulting complex shape of the precast concrete ribbed shells also meant a unique challenge for the Scottish Ten
team in capturing the complete surface of the exterior, from every possible angel with our line-of-sight 3D laser scanners.
The international team used its vast experience across the world, especially that gained from similarly complex Mount Rushmore
, to devise an on-site methodology that takes advantage of long-range time-of-flight scanners, mid-range time-of-flight scanners, phase-based scanners, custom built cantilever rigs, and the expertise of the Sydney Opera House’s regular rope-access team from Kerrect Group
With four laser scanners (five for the last few days of the project), we collected over 800 scans and more than 45,000 photographs.
The data management itself was monumental, but luckily I had a multi-page spread sheet to help keep track of every scan, ever accompanying panoramic image, every backup and every import into Cyclone for the master registration. Not to mention a mound of metadata sheets…
Daily I backed up the data, daily I registered it as it came in, and as the composite data set grew, I kept track of the coverage of the Opera House shells via a continuously updated registration of scans as well as (albeit a little more traditional) a large A2-sized printed plan and trusty highlighter. Marking as I went, the coverage plan allowed for morning review of content to prioritize and strategize with the team.
The continuous registration and review of data allowed for us to pin point trouble spots, where curves of the shells make line-of-sight for the scanners’ lasers difficult. And when we can't get the data from the ground, we use the rig. And in a few instances, even the rig couldn't reach and so the trusty rope-access team abseiled down the facades with a scanner, strategically placing it to capture otherwise impossible locations.
The rig and abseil scans were critical to capturing a complete exterior, while also being the most precarious and difficult to accomplish. These scans were reviewed individually, with great care to be sure data and accuracy was not distorted by any unintentional vibrations or gusty harbour winds. They also make for very cool scan images!
The Kerrect Group rope-access team has been absolutely vital in helping this project complete the full exteriors…and now they too have been digitally preserved with the opera house as seen in the top image!