Jitte Waagen, Hugo Huurdeman, Jill Hilditch
Introduction: 3D datasets and open science
In the field of material heritage we see an exponential increase in 3D datasets which provides the scientific community with interesting new possibilities. One of these possibilities is to share 3D models using online platforms, making use of so-called ‘3D-viewers’. Such platforms can really add value to 3D datasets, because they allow for presentation of scientific data in real-world dimensions, provide the possibility of annotating the models, and often feature tools to interact with the models. All these factors increase the impact of 3D datasets by making them insightful and creating a versatile medium for communicating in-depth knowledge on those datasets. Some useful platforms have already been developed specifically for archaeological collections, such as Dynamic Collections, a 3D web infrastructure created by DARK Lab, Lund University (https://models.darklab.lu.se/dynmcoll/Dynamic_Collections/) or PURE3D (https://pure3d.eu/), focusing on the publication and preservation of 3D scholarship.
However, the availability of online 3D datasets on such platforms also presents challenges: 3D datasets can be both complex to understand and interact with, and presentation tools often lack possibilities for bi-directional knowledge transfer, which can mean that the insights and narratives generated from the user-perspective are difficult to integrate and often ignored. From an Open Science perspective, it would be very interesting if platforms such as these would provide novel tools to create a rich multi-user workspace. These might include creating your own versions of 3D models and personal annotated collections, as well as multi-author 3D models or collections, and tools to enable discussions on those models and collections, and creating 3D-illustrated learning pathways.
The project that we introduce here, 3DWorkSpace, is an Open Science project funded by NWO (https://www.nwo.nl/projecten/203001026, see also the project announcement https://4dresearchlab.nl/3dworkspace-project-announcement/) and led by Jill Hilditch, Jitte Waagen, Tijm Lanjouw and Hugo Huurdeman. The goal of the project is to develop an online platform for interacting with 3D datasets and explore its potential to offer structured guidance, stimulate discussion and advance knowledge publication. This project is not so much aimed at creating yet another platform, but is intended as a pilot study towards the direct combination of realizing a platform and presenting case studies that will explore its potential, benefits and shortcomings. These case studies are focused on both deployment in the classroom as well as for peer-interaction in a research and professional context.
The 3D viewer technology is something quite different than the eventual user-facing platform in which you’d like to integrate it. Depending on the case, building a viewer from scratch might not be a good idea - especially when many good examples already exist. Since our goal was to explore the potential for creating the platform and to evaluate that, we decided to work with an existing viewer. In our explorations, both within the 4D Research Lab as well as in the Tracing The Potter's Wheel project (https://tracingthewheel.eu/), we evaluated various 3D viewers and 3D web technologies, such as 3DHOP (https://3dhop.net/), Aton (https://osiris.itabc.cnr.it/aton/), and Potree (https://potree.github.io/). Each of these has its specific benefits and drawbacks in terms of features, usability and technology, but eventually we chose Smithsonian Voyager (https://smithsonian.github.io/dpo-voyager/), an open-source 3D toolset. We found especially attractive the focus of Voyager on providing both a web-based 3D model viewer (Voyager Explorer) and an extensive authoring tool (Voyager Story). This authoring tool allows a user without specific technical experience to enrich 3D models via a web browser. A user can add, for instance, annotations as well as articles and combine these into tours. These enriched 3D models can, requiring some technical expertise, be subsequently published by integrating Voyager Explorer into a website. Given this capacity, Voyager ticked quite some boxes on our wishlist. A final important benefit of Voyager is that behind its development are professionals working hard to bring their product to as many users as possible and increase flexibility. Direct communication with the 3D Program team of the Digitization Program Office of the Smithsonian has been of fundamental value to the 3DWorkSpace project.
Having decided to use Voyager as the 3D-viewing building block of our platform, we turned to designing a platform in which it could be integrated, allowing us to reach our goals related to the open science approach of multi-authoring, learning and discussing. The challenge was to not fall into the trap of ‘featureism’, i.e. thinking up as many cool features as possible to integrate into the single most fantastic tool. This approach could lead to potential issues, including usability problems and implementation difficulties. Instead, we opted for a theoretical and methodological discussion which led to a baseline set of features that would facilitate the type of use and case studies that we were working towards. Thus, in addition to the basic browsing and search functions of such a platform, users should be able to:
- create and use their own 3DWorkSpace account (user authentication)
- compare 3D models side-by-side using multiple viewer panels (comparing models)
- annotate specific 3D models (annotating models)
- create and save personal or public collections of 3D models (collection making)
- add basic metadata to collections (describing collections)
- add comments to collections and reply to comments (discussing collections)
- create learning pathways for collections, incorporating textual content and hyperlinks to custom views of specific models (creating collection learning content)
Components of the 3DWorkSpace platform
The final 3DWorkSpace platform integrates the basic features we defined, such as collection making, annotation of 3D models and detailed discussions about collections. These features were implemented using three main elements: a storage server for 3D assets, the 3D viewer and authoring tools, and the 3DWorkSpace system itself.
The first crucial element of 3DWorkSpace platform entailed the storage and retrieval of the required 3D assets. These assets include 3D models, but also related annotations and additional metadata about the models. As we aimed for creating a bi-directional platform, these files had not just to be statically stored, but also dynamically editable. Voyager directly supports the WebDAV-protocol (https://en.wikipedia.org/wiki/WebDAV), which allows for editing files directly on a web server. Therefore, this WebDAV-server provided the foundation of the 3DWorkSpace platform.
Second, we integrated the Voyager toolset into the 3DWorkSpace platform. Specifically, we made use of two elements of the toolset: Voyager Explorer, the web-based viewer for 3D models, and Voyager Story, the authoring tool for creating the necessary files to display 3D models together with contextual information in Voyager Explorer (using Voyager’s structured SVX-format). Enrichments created using Voyager Story were automatically saved on the previously described storage server and could be visualized using the Explorer element.
Finally, the third crucial element was the 3DWorkSpace system itself, which seamlessly integrated the Voyager tools. The system made use of the Firebase app development platform (https://firebase.google.com/) for features such as user authentication and associated databases. The user interface (‘front-end’) was created via the React-framework (https://react.dev/), a framework to create interfaces using individual pieces (named 'components'). An advantage of React is that created components are highly adaptable, resilient and reusable, further contributing to the goals of the Open Science program 3DWorkSpace is part of.
The three discussed components led to the platform illustrated in Figure 1, 2 and 3. Users can browse and search models, collections and learning pathways. A unique feature of 3DWorkSpace is that users can always directly interact with the 3D models; in search results list, collections as well as detail views (Figure 1). The addition of multiple models makes directly comparing features of models possible, which is potentially useful for education, research and professional purposes.
Within the detailed views of collections (Figure 2) users can view and interact with associated 3D models, for instance by rotating models or by toggling visible annotations. Logged-in users can also edit 3D models and metadata using Voyager Story. These edits are directly saved on the WebDAV-server providing storage, offering a seamless experience.
On the right-hand side of a collection, various tabs allow for inspecting and editing collection metadata, notes and comments, as well as learning pathways. These features allow for unique possibilities in terms of bi-directional knowledge transfer: for instance, discussions with peers or teachers. Furthermore, learning pathways (Figure 3) allow for directly linking learning content with specific model views, such as close-ups of forming traces on ceramics. In this case, the multi-model view also allows for direct comparisons. Learning pathways will be further discussed in Blogpost 3.
Challenges, solutions and future work
While the 3DWorkSpace platform prototype provides various novel features, a number of challenges arose during its design and implementation, including user roles, potential system requirements and the authoring of enriched 3D models.
User authentication is an important issue. In the prototype version of the 3DWorkSpace platform, users can register and log-in to access commenting and editing features. However, there is no differentiation between roles; any user can directly edit or even delete any model, collection or associated data. In a future version of the platform, different user roles should be distinguished, to include administrators (having full editing access), editors (upload and edit models or collections) or commenters (only being able to comment on collections). This is especially important for use of the platform within educational settings.
The unique feature of displaying multiple editable models on search result pages facilitates model comparisons, but also resulted in issues with regards to high memory usage; a potential issue for users with older or limited computers. We resolved this issue by including only six models on any given page (e.g., in a search result list). In future work, model display via Voyager can be further optimized, for instance by initially showing low polygon-versions of models, or by showing thumbnails of models which only load after clicking on them.
A final challenge was the inherent complexity of the authoring tool Voyager Story for enriching 3D models with metadata, annotation and tours. Voyager Story has many in-depth features which make it an incredibly useful tool. However, this leads to some difficulties for initial users of Voyager Story due to its complexity. It was not feasible to resolve this within the scope of 3DWorkSpace, but we were able to alleviate it by creating extensive screencasts explaining the authoring process.
We hope with this blogpost to have provided you with some insights into our ideas and how they steered the development of 3DWorkSpace. We will comment on the platform evaluation and practical case studies in the next few blogposts!
Tracing the Potters Wheel
- Jill Hilditch - ACASA
- Jitte Waagen - ACASA / 4D Research Lab
Concept, development, evaluation
- Hugo Huurdeman - Open Universiteit
- Tijm Lanjouw - 4D Research Lab
- Caroline Campolo-Jeffra - Immersive Heritage
- Markus Stoffer - 4D Research Lab
- Ivan Kisjes - CREATE
- Saan Rashid - CREATE
Funded by NWO Open Science Fund (203.001.026)