My name is Paloma Sánchez Allegue. I am a Building Engineer from the Polytechnic University of Cartagena (Murcia, Spain) with studies in two masters related to architectural heritage and heritage conservation, where I specialized in 3D digitization using the techniques of digital photogrammetry and laser scanning. My training began in a self-taught way learning digital photogrammetry techniques, although I also took some courses on this technique. During my time at the university, I received two research and specialization scholarships, which allowed me to research, train and specialize in the 3D digitization sector for several years. I also had the opportunity to spend a period at the University of Bologna, (Italy), where I learned a lot about the optimization and post-processing of 3D models. All this training has allowed me to work currently for Dronica (idronica on Sketchfab) a technological company of 3D digitization and digital transformation, located in Spain, but with many international projects. My main job in the company consists in the management and realization of 3D scanning projects, scanning, generating point clouds and 3D models for very different sectors: heritage, naval, industrial, etc.
For some years, 3D scanning has been the preferred procedure to create accurate and real documentation of different objects. This registry will contribute to objects’ long-term conservation, especially for cultural heritage objects. The creation of digital information of the object will allow us to monitor, study, investigate, disseminate, and better understand the history and function of each object.
Although my current work is divided into different labor sectors, mainly I have always felt more accomplished in the Heritage sector, its conservation and dissemination. So, my public works and my models on Sketchfab have always followed this path. The majority are pieces of cultural heritage from different eras and styles, which have been chosen with singular care to represent the style of their construction or a particular era of our history.
Baroque altarpieces of churches of the Region of Murcia, Spain
My first works consisted of the digitization of two baroque altarpieces located in churches of the Region of Murcia (Spain).
The aim of these works was to disseminate the baroque heritage of southern Spain for its unique architecture and symbolism, and at the same time obtain reliable and accurate information to generate documentation, plans, take measurements of the sculptures, etc., which could serve as a basis for a possible future restoration, since until now there had been no graphic documentation of these architectural objects. The use and integration of different 3D digitization methodologies such as digital photogrammetry and laser scanning, as well as various post-processing operations of three-dimensional modeling and the application of realistic texture from images were key to the realization of these works and a precise and quality 3D model.
These works have been described in more detail and published in renowned magazines both in Spain and abroad. The first altarpiece can be found in the article “Documentación, conservación y difusión de un retablo a través de la Geomática: el retablo barroco de la Iglesia de San Miguel en Murcia”, e-rph magazine, nº 21, decembre 2017, ISSN 1988-7213. And the second altarpiece, in the article: “Interactive dissemination of the 3D model of a baroque altarpiece: a pipeline from digital survey to game engines”, Scires-it magazine, volume 8, issue 2, 2018, ISSN 2239 – 4303.
Historical pieces from the Archaeological Museum of Murcia (MAM), Spain
This work consisted of digitalization by digital photogrammetry of two pieces of the Archaeological Museum of Murcia. The work was undertaken with the aim of preserving two historical pieces without compromising their integrity and allowing a more exhaustive knowledge of the pieces through their disclosure thanks to platforms and web viewers such as Sketchfab.
Processional sculptures of Holy Week, Brotherhood of Cartagena, Spain
A line of digitization that I am working on recently is in the sculptures, especially religious sculptures and brotherhoods of Holy Week, a festival with a long tradition in much of Spain. The model of the sculpture of María Magdalena was made by digital photogrammetry, while the Nicodemus model was made with a manual light structure scanner. The obtaining of 3D models of these sculptures are increasingly demanded by historians and restorers, since they are sculptures that come out in procession and are exposed to constant dangers and damages. Having the 3D model of these sculptures is a great advantage when it comes to carrying out a possible future restoration or even the printing and integration of lost or damaged parts of the sculpture through 3D printing.
3D scanning is not an exact science; it depends a lot on the object being scanned, its material, texture, environment, lighting, etc. So, each object and each model is different. Sometimes it can become a real challenge, but in the end we must know how to choose the most suitable technique and equipment for its digitization, be it photogrammetry or laser or light structure scanner.
A great challenge that I have had has been to work with models of great magnitude, such as altarpieces, objects that are difficult to scan and access due to their complex geometric shape and height. The biggest difficulty has been to integrate different scanning techniques, laser scanning and photogrammetry, to obtain point clouds and meshes of the areas where the scanner could not access, to produce a model close in form to the actual object, a model that does not lack information or contain invented information.
As a result, heavy models and meshes with a large number of triangles are obtained that few computers can work and visualize. Thus I must lighten these meshes, converting them into quadrangular meshes or reducing their number of polygons, but always looking for a balance between this reduction in size and the quality of the final finish. Finding this balance is the biggest challenge for me.
I use Sketchfab because it is an easily accessible platform for both users and viewers, where 3D models of different styles, sectors, interests, etc., are shared. It is able to integrate models of people from all over the world, creating a wonderful network of contacts in this sector with the same interests as me. In addition, it is a platform with exceptional lighting tools, incorporation of normals maps, textures, etc., thanks to which, the models acquire an incredibly similar result to reality and can even be viewed with virtual reality glasses, where our models and those of other great professionals from all over the world take on a life of their own. Sketchfab has been able to reach all corners and make us part of the great work that is being done around the world in digitizing our heritage, our assets, our history and ultimately, our entire lives.