In the Mapping the Via Appia project, a traditional two-dimensional geographic information system (GIS) and relational databases are being employed to accurately store the data gathered during archaeological fieldwork. However, since archaeology inevitably involves the third – vertical – dimension, the Mapping the Via Appia project is at the frontline of interdisciplinary and generic 3D GIS development.
Mapping the Via Appia in 3D
Over the past decades, the use of virtual 3D technologies in archaeology has increased tremendously. Projects in which scanning techniques are used to obtain 3D measurements or in which 3D modelling software is used to generate virtual reconstructions are numerous. However, the application of 3D technologies as an information system in which the measured field data can be systematically queried based on attributive information collected in the field and in which sophisticated 3D analyses can be conducted, is not yet widespread. Especially for complex archaeological sites, in which structures and objects are scattered over the study area, a 3D system as such would aid to understand and reconstruct complex archaeological sites.
The developed 3D GIS allows archaeologists to spatially store, share, visualise and analyse the complex archaeological features in a virtual 3D environment. Furthermore, the 3D GIS allows to include in 3D georeferenced historical images and virtual 3D reconstructions in a scientifically transparent way. At the base of the 3D GIS lies a sophisticated cloud-based data infrastructure, providing various services to different clients ranging from an interactive web viewer to a dedicated desktop viewer. The project has produced a unique research instrument for the archaeologists working in the study area. It provides functionalities and analysis tools which have never been available as such before. Additionally the developed 3D GIS offers, yet unexplored, state of the art opportunities to present the research results to the archaeological research community and the broader public.
3D GIS framework
The framework for the 3D GIS consists of various components which can be grouped in four parts. They are all part of an infrastructure that makes them accessible via the internet as services.
A) Data acquisition & processing
The reference point cloud of the study area was laser scanned using Fugro´s DRIVE-MAP service. In order to generate more detailed 3D representations of the archaeological objects, image-based modelling techniques were applied using Visual SfM components. To integrate these captures in the laser point cloud, both automatic and manual alignment functionalities have been implemented. Functionality to identify objects in 3D and to link these to a relational database has been implemented, which is essential to allow the systematical querying of the objects based on their fieldwork attributes.
B) Analytical tools
To systematically analyse the study area, the infrastructure offers processing and viewing services on which both a desktop (based on OpenSceneGraph) and a web client (based on WebGL potree, see potree.org) have been developed. These clients offer functionalities to query the archaeological objects based on their attributes, integrate 2D mapping services, visualise 3D sections and to measure distances, angles and volumes.
C) Archaeological reconstructions
To produce archaeological 3D reconstructions, the infrastructure offers functionalities to download sections of the dataset. This allows researchers to use the data in dedicated 3D modelling software. In addition, the infrastructure offers functionality to upload multiple hypothetical 3D reconstructions. These reconstructions are presented as a service, allowing to be visualised in both the web and desktop client.
D) Presenting and sharing the results
Especially the web viewer offers clear opportunities to share the research results with other scholars and a broader public. The viewer allows people to browse through the dataset in 3D, without having to install software on the local machine. Furthermore we have developed services which are accessible through an Oculus Rift.
The 3D GIS for Mapping the Via Appia has been developed in close collaboration with the various archaeologists involved. The system is now in place and ready to be used by our research team, both staff and students. All components developed in the project are open-source and thus available and reusable by other research teams. We invite other researchers to use and enrich the code and components we have developed.
Based on tools that have been developed and used in the context of Mapping the Via Appia, the NL eScience Center has produced a web viewer to visualise the 3D point cloud for the Netherlands (AHN2). This dense massive point cloud can be accessed at ahn2.pointclouds.nl. More information about the related project can be found here.
Please visit the OUTPUT section of this website to view publications on the 3D GIS and virtual 3D reconstuctions of architecture along the Via Appia, plus the poster for CAA 2015 Siena!
Maurice de Kleijn SPINlab – VU University Amsterdam
Rens de Hond Radboud University, aff. SPINlab – VU University Amsterdam