Roman Catacombs in 3D

5.03.2009 | |




"The leader of the project, Dr Norbert Zimmerman of the Vienna Academy of Sciences, was behind the idea to use laser scanners to record every part of the Catacombs.
His scanner, which looks like a cylinder on a tripod, stands a metre or so high and is a piece of kit you usually find in the construction industry.
Gone are the days when archaeologists just used shovels, brushes and sieves to unearth the past.
The scanner has been placed in hundreds of different locations in the Catacombs.
It turns slowly, sending out millions of light pulses that bounce off every surface they come into contact with. The light pulses rebound back into the scanner and are recorded on a computer as a series of white dots, known as a 'point cloud'.
Gradually, every wall, ceiling, and floor is bombarded with the dots, enabling the computer to build up a picture of each room.
Eventually, the computer completes a 360-degree, three-dimensional, moving image of that room, with every surface looking like it is made up of small white dots.
At the same time a camera on the scanner takes a picture of each surface. That information is also fed into the computer enabling colour to be added to "fill in" the dots.
'Real data'
When the process is finished, it looks like an actual film of the particular room in question.
In all, four billion dots were recorded, enabling practically the whole catacomb to be documented in this way. Only a handful of small spaces were left out because it simply was not possible to get the scanner in.
The final result is astonishing.

The catacombs of Saint Domitilla stretch for about 15km (9 miles)
On a computer screen, you can now see the whole underground complex. Using different buttons on the key pad, you can zoom in on the tunnels.
You can travel 'through' walls, down corridors and into chambers, giving the first real sense of its beauty, scale and detail.
Paintings on walls, which have not been seen in nearly 2,000 years, are now visible - their colours vivid and clear.
'It is not a virtual image, it is not animation - what you are seeing is real data,' says Mr Zimmerman."
[BBC]