Over the past few months I’ve been hard at work producing an animation of the Environment Agency LIDAR survey of the Stonehenge World Heritage site. The resulting video is currently playing on an HD plasma screen in the “Making History: Antiquaries In Britain, 1707–2007” exhibition at the Royal Academy in London.
For the more technical minded people, the underlying DEM (Digital Elevation Model) is 8000×8000 at a resolution of 1m. You can view the video in HD over at Vimeo.
Some years ago, when I was doing my MSc in archaeological computing, I heard about a curious project led by Alan Chalmers, then at the University of Bristol, that aimed to digitally recreate accurate simulations of different light sources. These would then be used to “light” 3D models to show more accurately they may have looked under certain conditions, such as goose fat tallow candlelight. The light absorption and reflectance properties of objects and walls etc was also taken into consideration.
It seems that Alan’s research is progressing well at Warwick University, and is currently featured on the BBC Technology website. Light is often forgotten when interpreting life in the past, along with the fact that it wasn’t always daylight in days of yore. I’m please to see this get some popular publicity!
At the time, Alan was using software called Radiance, but from looking at the site, I’m not sure if it’s still being developed, but it might be worth a look if you want to get started.
As computer hardware gets ever faster, and as 3D software gets ever more powerful, new opportunities always present themselves. Crucially, as the ‘average’ home computer reaches a certain stage (where they generally have a 3D accelerated graphics card and a broadband connection) using 3D to explore and interpret the past - interactively - is ever more possible.
Rendering vs Realtime
Most images of the past generated by 3D software packages are pre-rendered. That is, they are static images or movies that you cannot interact with. The reason that you can’t wander about these virtual pasts on your computer, like you can in a game, is that more often than not, it takes a very long time for a computer to ‘render’ the image from the 3D geometry that it is constructed from. Many of the images that I have produced often take hours (even days) to render, having taken days to research and create.
That is set to change, however. Computer games have been exhibiting more and more sophisticated “engines” that produce the in-game graphics. They use the graphics processing unit (GPU) present on modern video cards to the maximum extent. The latest video cards are almost computers in their own right, dedicated to producing ever more photo-real results.
A game called Crysis recently came to my attention. It is (as usual) a “first person shooter” where you roam around a fictitious landscape killing things and performing missions. They don’t usually grab my attention, but this one did for one reason: the graphics engine (CryEngine2) and level editor. The graphics in this game are nothing short of astonishing. What the game does in realtime, 30 times a second or more, would take some software that I use several hours to render. This video shows what can be achieved in realtime, on a computer with the latest video card:
What is even better, is that you can use the same engine not just to play the game, but to create new content (or levels) for it.
Maybe soon, we will be able to use these tools to interpret the past. This kind of technology, if affordable, would certainly speed up the process of creating landscapes and scenes, ultimately allowing archaeologists to experiment with their interpretations in 3D without being detrimental to budgets in terms of money and time. It could allow still images to be generated very quickly, as well as animations, and free-form interactive worlds to wander about in and explore.
One of the stills I produced as part of the Arun Visualisation has been used by E-On Software to showcase their excellent EcoSystems Generation II instancing feature. Vue was used extensively for the animation, as well as 3ds Max, AutoCAD, XFrog, and numerous GIS and imaging packages.
It’s one of my favourite images, and I couldn’t quite believe the quality of it when the render finally finished. It’s nice to see it being used for more than just archaeology!
One of the 3D animations I’ve been working on at Wessex Archaeology is now available online with an introduction to the project. It’s been along time in the making, and like any archaeological reconstruction/visualisation, it’ll never be perfect.
So click the movie above (hosted on the rather excellent blip.tv) and delve back in time 8000 years ago into a Mesolithic landscape that’s now 8 miles off the southern coast of the UK, and up to 30 metres under the sea.
I’ve been using Sketchup for a while now (demo version), initially seeing it at the MacExpo in London last year. It’s a brilliant tool, taking (in my opinion) a whole new approach to 3D modelling. It couldn’t be easier to use.
Sketchup introduced a tool to export models straight into Google Earth, and the rest is history. The company was bought by Google, who now offer a free version of the software, which is limited in what you can import or export. You will still need the ‘pro’ version if you want to use the software in conjuntion with (i.e. exporting to) CAD or 3D visualisation software.
Archaeologists - it’s very easy indeed to import an AutoCAD DWG into Sketchup (or aerial photos, DEMs or a combination), and have fun trying out different interpretations. You can then export them to Google Earth.
It’s a lot of fun, and dare I say it, rather useful.
The use of terrestrial 3D laser scanning devices is increasing in all surveying areas including topographic surveys and building recording. However, a dichotomy exists in that the deliverables produced by such surface-rich acquisition devices generally tend to be surface-less clouds of points.
This article discusses the use of a Callidus 3D laser scanner on a multi-phase site at Knowlton, Dorset. This site originally featured a Neolithic henge earthwork (circular bank and ditch) with two causeways crossing the ditch. Later, in mediaeval times, a church was built in the centre of the henge to effectively Christianise the pagan monument.
The purpose of the exercise was to acquire not only a complete dataset of the earthwork for topographical analysis, but also a high-resolution scan of the church fabric itself.
Archaeoptics have just announced the completion of their project to 3D laser scan one of the neolithic flint mines at Grimes Graves in Norfolk, UK.
They scanned the entire mine, which is roughly the shape of a tree root system, at a resolution of 1mm, resulting in a dataset of 1.1 Billion measurements (vertices). That’s 2.2 (US) Billion real polygons - a really huge dataset. I’m looking forward to seeing what the results look like!
From the resulting 3D model, archaeologists will have a detailed record of the mine for archive, as well as being able to take accurate measurements, cross sections and use it for virtual tours where public access is not possible for safety reasons.
