The Necessary Role of Metadata Standards in the Shelf-life of 3D Data
Annotations by Tamara Karr
Definition of Project
This annotated bibliography examines the challenges and benefits of preserving the 3D data of archival materials through the use of well-developed metadata practices. The bibliography focuses on topics related to metadata standards for 3D data as well as the challenges that arise from the long-term preservation of a developing technology. This bibliography helps provide a framework for understanding the needs associated with the preservation of 3D scans and how archival and metadata standards can be used to assist in limiting obsolescence. It does not include coverage of 3D scanning projects, or equipment reviews. Terminology such as “3D visualization,” “3D modeling,” and “Cultural Heritage” were used when searching for resources. The items selected and presented here date from 2009 to 2018. The publication venues for the resource range from peer-reviewed journal articles and conference proceedings, to more informal presentation slides.
Annotations
This paper explored the implementation of European metadata standards, to create best practices for 3D data. Andrea D’Andrea and Kate Fernie presented this paper as part of the 3D-ICONS project. The 3D-ICONS project focused on improving Metadata and Thesauri. They specifically focus on EDM (European Data Model Primer) and CARARE (Connecting Archaeology and Architecture in Europe). They explored how these metadata standards could be used for 3D scans. Their developed metadata standard mapped CARARE to EDM and included the elements: Was_digitized_by, Has_created, Consists_of, Had_general_purpose, Had_specific_purpose, and Created_derivated. To capture the software used in the scanning process they created the elements Used_software_or_firmware and Happened_on_device. This article outlined what the 3D-ICONS project believed to be the best practices for the metadata schema of 3D scans. 3D-ICONS’s schema displayed an understanding of the importance of capturing the software used to create the 3D scans, by making it a required element.
D’Andrea, A., & Fernie, K. (2013b). CARARE 2.0: A metadata schema for 3D cultural objects. In Proceedings of the 2013 Digital Heritage International Congress (DigitalHeritage), October 28-November 1, 2013, Marseille, France, Volume 2 (pp. 137-143). Institute of Electrical and Electronics Engineers, Inc. doi: 10.1109/DigitalHeritage.2013.6744745 [1]
In this paper the authors explored the quality control of 3D data, the creation of a metadata standard and CRMdig schema for the purpose of assuring quality 3D models. Their main goal was to provide provenance data concerning 3D models along with quality paradata. They explored the 3D ICONS project, a 3D modeling project containing 3,000 archeological site models, funded by the European Commission’s ICT Policy Support Program. With the metadata standards created by the 3D ICONS project, they could apply simple and clear descriptions of the processes of digitization and rendering. This description would enable the history of the 3D model to be included. The EDM (Europeana Data Model), which stores the records of millions of items from European galleries, archives, libraries, and museums, was also explored. In order to make EDM applicable to 3D data, they suggested mapping it to CARARE (Connecting Archaeology and Architecture in Europe). This would allow for born-digital resources, such as 3D scans to be added. They also suggested the addition of relations such as, Was-digitzed_by, Has Created, Consists of, and Created Derivative should be added to the CARARE 2.0 standard. Though they are optimistic about the outcome of such a schema they pointed out that there have been limited collections following their protocol. They suggested that more 3D model records need to be added to CRMdig in order to have a well-developed standard.
Doyle, J., Viktor, H., & Paquet, E. (2009). Long-term digital preservation: Preserving authenticity and usability of 3-D data. International Journal on Digital Libraries. 10(1), 33-47. doi:10.1007/s00799-009-0051-7 [2]
In this paper the authors explored the long-term preservation of 3D data, in relation to the development of a framework built to ensure authenticity and usability. To create this framework the authors looked at the issues that arise from software obsolescence. They recognized the practice of migration while expressing concerns over losing the original/authentic sense of the digital file. To combat this issue, they suggested preserving the software used to create the 3D model, along with the metadata to a framework. For the metadata standards, they used PREMIS (Preservation Metadata: Implementation Strategies) and METS (Metadata Encoding and Transmission Standard). In their framework they were able to create a place where original scans could be viewed along with their original software. In conclusion, the authors expressed concern over the long-term adaptability of their framework. Technology changes would add more information to their framework, possibly stretching it past its capabilities.
Hauck, O., Kuroczynski, P., Dworak, D., Lutteroth, J. (2015). Virtual Museum of destroyed cultural heritage – 3D documentation, reconstruction and visualization in the semantic web. In proceedings of the 2015 International Conference, Virtual Archeology (Methods and
- benefits), June 1-June 3, 2015, Saint Petersburg, Russia, (pp 54-61). State Hermitage Publishers. http://www.virtualarchaeology.ru/pdf/281_va_book2015.pdf
In this article the authors explored the creation of the metadata schema, CHML (Cultural Heritage Markup Language) for 3D models of destroyed physical objects. These models are made from many layers of points, which reconstruct the object from the base upward. Because of this technique, the authors created a metadata standard, using CH (Cultural Heritage) standards as a base. In CHML the authors include information about the destroyed physical object, the process of collecting data, acquisitions, interpretation and the 3D modeling. They also included information about the geometry of the original object, lighting and camera settings. The authors also included the attribute TYPE for the elements object, source, activity and actor. The authors believe that CHML successfully catalogs the 3D models of destroyed physical objects. However, they do point out that limitations arise from the lack of standardized vocabulary.
In this article the authors explored developing best practices for 3D data preservation, while going through the process of data creation. The authors developed a three-step procedure; Capture, Process, and Publish, while creating 3D scans of items in their collection. Capture included scanning standards, while Process focused on the preservation of the original scan and cleaning it to be useable. Publish, included sharing the 3D scans online through, Sketchfab. For this project they selected Digital Public Library of America (DPLA) metadata standards. The authors concluded by stating that the practices they developed may not be adaptable to other collections and in order to develop best practices for 3D/VR collections, a national standard needs to be created. The authors are optimistic about this outcome, citing their involvement with multiple researchers and universities with such a goal.
Kuroczynski, P., Hauck, O., Dworak D., (2014) Digital Reconstruction of Cultural Heritage – Questions of documentation and visualization standards for 3D content. In Proceedings of the 5th International Euro-Mediterranean International Conference on Cultural Heritage,
- November 3- November 8, 2014, Limassol, Cyprus. https://www.academia.edu/9189049
In this paper the authors explored the preservation and best-practices of 3D data, while considering impacts on data usability. The authors suggested the use of CIDOC-CRM (Committee for Documentation of the International Council of Museums – Conceptual Reference Model), as it provides many descriptions of cultural objects. CIDOC-CRM has 164 proprieties that make it adaptable to digital materials as well as hard-copy materials. The authors also suggested the best storage protocol involves MVC (Model-View-Controller) models, because it allows for storage of any kind of data and manipulation. A concern that the authors had, is that 3D models are currently limited to 65,536 vertices per frame, which requires splitting models. This suggests that the storing of 3D models may require multiple sets, making the processes of preservation more complex.
Pierre Alliez, Laurent Bergerot, Jean-François Bernard, Clotilde Boust, George Bruseker, et al.. (2017) Digital 3D Objects in Art and Humanities: challenges of creation, interoperability and preservation. White paper. In Proceedings of PARTHENOS Workshop, November 30-
- December 2, 2016, Bordeaux, France. European Commission; Horizon H2020 Projects. https://hal.inria.fr/hal-01526713v2
In this white paper the authors explored the preservation of 3D data and the implementation of metadata standards. This white paper was created in 2016 as a result of a PARTHENOS (Pooling Activities, Resources and Tools for Heritage E-research Networking, Optimizing and Synergies) workshop held in France. A wide variety of people contributed to it from several universities around the world. In the white paper they covered a wide range of issues related to the use and preservation of 3D scans. On page 47 they outlined the necessary elements for a schema. The elements included Actors, Objects, Goals, and Tools. They also explored the pros and cons of the most popular metadata standards for 3D scans: ARCO (Augmented Representation of Cultural Objects), CARARE 2.0 (Connecting Archaeology and Architecture in Europe), CRMdig (Conceptual Reference Model Digital), LIDO (Lightweight Information Describing Objects), METS (Metadata Encoding and Transmission Standard), and The STARC (Science and Technology for Archaeology Research Center) Metadata schema. They recognized the values of each metadata standard while expressing concerns over their shortcomings. Overall, the greatest concern expressed by the panel was the development of another metadata standard, when others are already available.
Moore, J., Hannah K. S. (2018). Who Cares About 3D Preservation? IASSIST(International Association for Social Science Information Service and Technology) Quarterly. 42(1), 1-14. https://doi.org/10.29173/iq20
This article addressed best practices for 3D preservation. The authors expressed concern that there was not an expansive enough adoption of standards to know which are best practices and best metadata standards. The article went into detail about the different ways of creating 3D models as well as how they are captured. They also shared some case studies which led them to ask three questions: What should be preserved? What metadata is necessary, and What is the role of emulation in 3D preservation? Though they were unable to provide answers to these questions they did suggest that the implementation of metadata standards, specifically for 3D objects, is paramount. The standards would aid in preservation and in the advancement of the technology. They concluded by suggesting that best practices need to be developed with the data creators, and archivists.
In this presentation, the creation of a prototype tool to contain 3D schematic models was addressed. The prototype tool contained over 3,000 3D schematic models of ancient structures. While creating the prototype tool, technological and access issues arose. As a result of these challenges the presenter asked: Do we need both, standards and best for 3D data? What 3D versions of the past should, or can we preserve? How do we preserve process and product 3D? To answer these questions, they created a workflow model along with metadata elements. Their metadata elements included: Created By, Created On, Software, Attributes, Reality Based, Resolution, Relative Resolution, Geofef.Inof., No. Triangles, No. Points, and Copyright. Along with this metadata standard he was able to add links to images of the models. The presenter believed that this structure will help create a smoother workflow that can be applied to other projects.
Richards-Rissetto, H., Schwerin, J. (2017). A catch 22 of 3D data sustainability: Lessons in 3D archaeological data management & accessibility. Digital Applications in Archaeology and Cultural Heritage. 6, 38-48, http://dx.doi.org/10.1016/j.daach.2017.04.005
In this article the authors explored, 3D archaeological data management as a way to protect data from obsolescence. The authors pointed out that a lack of 3D data standardization resulted in limited accessibility to 3D models. The authors also stated that the metadata standards, CARARE (Connecting Archaeology and Architecture in Europe) and 3D-COFORM (3D-COllection-FORMation) are useful. However, to ensure better shelf-life, continual management of the data must be implemented. The authors believe that for archaeologists to archive data in a sustainable way they must follow record standards, fill storage requirements, deal with uncertainty and security issues. While their suggestions for data management and protection against obsolescence are strong, they suggested that there are limitations due to the large amounts of data being created. A way to handle large numbers of 3D models needs to be developed.
