My name is Alicia Colmenero Fernández, a Sketchfabber from Galicia. I am a doctoral candidate and researcher at the University of Vigo in the field of new technology applications for heritage and virtual archaeology. I am also a professor of New Technologies applied to the East at the Roots of Europe Foundation.
I have been trained as an historian and in multimedia engineering (Universidad Oberta de Cataluña), which allowed me to work recently in two fields: the digitization of archaeological sites and 3D modeling for virtual reconstructions. The second field in which I have worked in recent years has been the three-dimensional reconstruction of archaeological models for audiovisuals in museums and for television series. I have been able to participate as a freelancer with everything from documenting to modeling scenarios. Being able to learn the use of new film modeling techniques has greatly improved my work methodology. Currently I am finishing my doctoral thesis and looking for funding to continue researching in the field of vision and artificial intelligence for heritage conservation.
In the area of digitization, the major challenge that I have encountered has been to document large archaeological spaces, digitizing them with a SLR camera. I have always tried to perform professional quality work with low economic investment. Many excavations have limited funding and sometimes the materials with which the site is built put their conservation at risk. Therefore it is necessary to create documentation for each campaign. There are many conditions that cause a deposit to be at risk of this loss of information.
Among the works that I was able to do, I would highlight what I could do in Magdala, Israel. Documenting this site was especially significant for me due to its large dimensions. I had to face challenges such as working in conditions of extreme heat, not being able to rely on support technology, and dealing with problems such as light variations that occurred throughout the capture of the data collection.
To help the image overlap process I used a small gps connected to the camera that added to the exif of the local coordinate images. This proved to be very helpful when it came to obtaining a model with a high level of detail. Although these gps usually have a high range of error in their global coordinates, nevertheless they presented very good results in local positioning and this greatly helped the photogrammetry software to position the cameras. This work was able to be completed with the permission of the archaeologist director of the excavation, Marcela Zapata, and with the knowledge of the Institute of Antiquities of Israel.
Turuñuelo de Guareña, Spain
A similar process was the one I used to document the last two campaigns of Turuñuelo de Guareña. This site is a jewel of the Tartessian world and due to its fragility it is necessary to document each campaign. In this case I made the digitization of the whole field with photogrammetry; for the 2018 campaign I combined the images taken on foot with 12 images for a geolocated orthophoto of a drone flight. This approach helped the positioning of the cameras in the generation of the point cloud. The archaeologist Sebastián Celestino Pérez was able to benefit from this work by sharing the digitized models of the site with the worldwide scientific community who were interested in this site; he used Sketchfab, which also allows private models to be uploaded.
Tools and Workflow
I have been able to achieve the best results and the highest level of precision with a mixed technique of photogrammetry and laser. I did this work with the authorization of archaeologist Celso Rodríguez Cao at the Mitreo de Lugo, Spain. Together with the University of Vigo we completed the digitization using a laser scanner and more than 1000 photographic images to finally optimize the model for virtual reality (Oculus vr), a process that I share in this publication.
The levels of precision and quality of the model in both texturized and vertex color turned out to be exceptional. Sketchfab is an ideal tool for viewing of models of high geometric density, obtaining the best results when applying light conditions with the predetermined hdr.
All these works were carried out without funding, so as a researcher I consider that Sketchfab is a very useful tool when it comes to sharing the photogrammetric documentation of deposits, pieces, etc. It is great to be able to generate an archaeological 3D database that until now was not possible. Additionally, the simplicity of the platform allows non-specialized users to include images with rendering quality and use them for their studies, conferences, etc. With intuitive movements, any user can analyze models with great precision of detail and just take a screenshot, choosing the right view to have the desired image without having to resort to complex rendering programs.