Tom Shelley explains how rapid prototyping is being used to recreate a treasure from the past
A partly destroyed ancient Roman statue is being reproduced using modern technology. The aim is find out how it originally looked.
The statue was discovered in 2006 within the ruins of the ancient Roman town of Herculaneum. It is thought to represent a wounded Amazon warrior and was likely destroyed by the same volcanic eruption as Pompeii in 79AD. However, the ash preserved the paint on the hair and eyes; a rarity from the period.
As a result archaeologists at the University of Southampton and the Herculaneum Conservation Project contacted Warwick Manufacturing Group (WMG) after hearing about their expertise in laser scanning, rapid prototyping and computer graphics.
Dr Mark Williams from WMG took a Metris laser scanning probe and measuring arm to the site in order to scan the statue. Despite the scanning system being capable of gathering up to 80,000 measurement points per second, the process still took four hours. The point cloud data was then post processed to produce a usable surface mesh.
Dr Gregory Gibbons, a research fellow at WMG says: "All the scans taken were optimised to ensure that there were no stepped surfaces and the point cloud was filtered to a point spacing of 0.3mm. Boundary points were inserted to ensure surface definition and small holes in the mesh were filled using curvature analysis. This was achieved using Metris Kube software.
"To prepare the model for stereolithography, the surface model was hollowed to create a 3mm wall thickness shell in order to reduce the rapid prototype build time and the overall weight of the model. A hole was then created in the base surface to allow resin to drain from the hollow part after construction. The model was produced using an SLA 5000 machine from 3D Systems in Watershed 11122XC resin from DSM Somos, with a layer thickness of 0.1mm. The rapid prototype 40 hours to make."
Members of the University of Southampton team used photography to provide a record of the texture and colour of the painted surfaces and are now digitally re-modelling and re-painting the head of the statue, using techniques derived from the film industry.
Dr Graeme Earl from the Archaeological Computing Research Group at the University of Southampton says: "This visualisation will provide us with an otherwise impossible view of how the original statue may have looked in context, and allow us to experiment with alternative hypotheses about its origins. Painted statues from this period are unusual and digital technologies offer a host of new possibilities to researchers in archaeology. Over the coming year we will be working with experts in Roman sculpture and painting from around the world in order to produce the most accurate simulations possible."
Pointers
* The damaged bust was scanned in and photographed. Rapid prototyping was used to produce a replica.
* The work now focuses on re-creating how the original statue would have looked.