It you’re interested in 3D scanning and Cultural Heritage, then you’ve probably noticed the Discovery Programme on Sketchfab. They have been very actively publishing new models and I was interested to learn more about their efforts. Today I talk to Anthony Corns who is their Technology Manager.
Hi Anthony, can you tell us a bit about the Discovery Programme?
The Discovery Programme is a research centre for archaeology and innovation in Ireland. We were established in 1991 by the then Taoiseach (Irish Prime Minister), Charles J. Haughey with the mission to explore Ireland’s past and its cultural heritage through advanced research in Irish archaeology and related disciplines and by disseminating these findings widely to the global community. The culture of the Discovery Programme is to carry out research within an interdisciplinary framework so that all research subjects such as humanities, sciences and technology work together in furthering the understanding and promotion of archaeology. Our activities are not limited to any specific time period therefore we could be working on anything from ancient stone carvings produced over 4,000 years ago to important historical buildings from the recent past.
What is your role in the company?
I work as Technology Manager within the organisation and as a member of the IT & Survey team. Our role is to support the archaeologists through the application of new technology to their own research projects, whilst also carrying out our own applied research. We have a wide range of research activities from geophysics to data archiving, but currently our major focus is the 3D documentation and presentation of cultural heritage objects.
One of the 3D documentation projects we have been working on over the past 3 years is the EU co-funded project 3D-ICONS. This project brings together partners from across Europe with the relevant expertise to digitise architectural and archaeological monuments and buildings in 3D with the aims of establishing a complete pipeline for the production of 3D replicas of archaeological monuments and historic buildings covering all technical, legal and organisational aspects. It also aims to create 3D models and a range of other materials (images, texts and videos) of a series of internationally important monuments and buildings. All the content created is to be made available online and its metadata hosted by Europeana cultural portal. The models presented on Sketchfab by the Discovery Programme are only 150 of the total 4000 models which have been created; these will be available, together with videos, image renders and information about each heritage object at our dedicated website www.3dicons.ie which will be launched in spring 2015.
Which scanning technologies do you use? What works best in which case?
Cultural heritage objects to be documented in 3D range significantly in size, and the scale of object normally determines the scanning technology we apply.Landscapes and expanses of terrain containing the relict features of human activity are the smallest scale features we record. These are captured utilising a range of aerial survey techniques including fixed wing and helicopter based lidar (survey areas > 4km²) which enable us to remove vegetation cover and reveal the morphology of the monument beneath. Hopefully this year we will purchase a UAV to enable focussed aerial surveys and SFM models to be created.
For building and monuments which have some upstanding remains, we employ the use of terrestrial laser scanners (Faro Focus 3D) to capture this data, with the addition of subsequent gigapan imagery if colour texturing is required. We normally scan to an effective resolution of 1cm to ensure the structure of the monument is fully recorded. Many of the surveys we do could be carried out by SFM, however some environments we work in have very poor lighting (e.g. chambered tomb) making this approach difficult. Another factor in the selection of laser scanning as the data collection method of choice is the ability to check sufficient and quality data has been gathered in the field. With SFM surveys most of the processing is carried out back in our Dublin office. Any loss in data or poor models would require another trip to gather the data, which is quite time consuming if you have to travel to Skellig Michael, a remote island of the west coast of Ireland.
For smaller objects such as statues, high crosses, carved stones or any architectural features we use an Artec EVA close range scanner. Again, we can ascertain in the field what level of accuracy and 3D coverage has been achieved. For smaller objects such as modelling artefacts or very small architectural; fragments we would employ SFM.
What are your most successful/impressive results so far?
We have worked upon a wide range of monuments, each with their own merits and challenges. The level of details we have been able to capture model, and the and final look of our High cross 3D models makes these some of the most impressive models currently on display. These objects are of some of the most impressive early Christian stone monuments in Europe, with these examples dating to around 900AD. They were originally built as public monuments to teach the public scriptures from the bible and contain amazing detail and design especially in their interlaced decoration. We have removed the colour texture from the 3D models created as this often camouflages the finer details of the carvings, instead we have opted to use an ambient occlusion texture together with environmental lighting effects to enhance their detail.
In contrast some of the other models we have produced may not be as visually striking, but in terms of the challenge and effort involved in capturing and processing the data they are of equal importance. The surveying of Skellig Michael, presented a testing environment to capture data due to the variability of the weather, the remote and rugged nature of the site, and the fact that it is open to tourists throughout the year. The shear monumentality of the Walls of Derry, 1.6km in length, presented a daunting challenge. This survey, in an urban environment was completed in 14 days using the Faro laser scanner.
One of our greatest achievements was to develop a pipeline to enable the meshing, retopologisation and modelling of very high resolution terrestrial laser scan data for viewing within a web-browser. In the past two years the advances in software capabilities and the development of WebGL has allowed for the presentation of detailed models using only web browser without the addition of plug-ins or additional software.
Which Sketchfab tools are important to you and how do you use them?
Sketchfab has provided the Discovery Programme with a great set of services to enable the online display and interaction with our 3D content. The ability to rapidly get obj files and associated texture maps online is particularly significant. Once our models are online we visually adjust the environmental and camera settings to maximize the impact of the model. We have only just started to use the annotation tools, but we see great potential in marking up our models with interesting information or linking to other 3D models on Sketchfab.
One unforeseen benefit of using Sketchfab was the ability to publish point cloud data online. Online dynamic display and navigation of point cloud data is fairly difficult due to the massive files sizes. Through the sampling of data (usually to 1% of the original data) and the creation of obj files from the point cloud data we have been able to offer the user some level 3D interaction with point cloud data. This may not be as effective as visualizing the original full point cloud data but it offers an excellent solution for the public who lack the software tools to access the full cloud.
Thanks so much Anthony!