Photogrammetry of Uncle Tom’s Cabin Vase

By Mackenzie Brooks with Dave Pfaff and Ron Fuchs

Introduction

This toolkit shares an emerging technique for studying and disseminating cultural heritage objects. Specifically, it documents the process of creating a 3-D model with photogrammetry. It also contains activities and materials for using existing 3-D models in the classroom.

We will use the Uncle Tom’s Cabin vases previously approached via the lenses of History and English.

Perspective

As Digital Humanities Librarian, I am interested in digital approaches to cultural heritage materials.

Digital Humanities (DH) is a community and set of practices at the intersection between digital methodology and humanities inquiry. Practitioners might apply statistical methods to a corpus of 19th century literature or use GIS to map ancient locations. DH work is often a collaborative endeavor – scholars work with students, librarians, and technology specialists to produce a public-facing digital project. In many cases, these projects require a process familiar to librarians – the remediation of cultural works for preservation and wide dissemination.

We have established practices for replicating printed texts or two-dimensional art. Students can read books on their phones and faculty can create Powerpoint presentations of 19th-century photographs. These digital surrogates may not fully stand in for their physical objects, but until recently, there has been no equivalent surrogate for three-dimensional objects.

The development of 3-D modeling, 3-D printing, and virtual reality by fields like engineering, geology, and the video game industry has created a landscape of tools and platforms that can be borrowed for the cultural heritage sector. Building a 3-D model not only creates a digital object for manipulation, but also creates useful data for the study of that object. Libraries and museums can now add 3-D objects and their data to their digital collections.

As an example, the Smithsonian Digitization Program Office has centralized their 3-D efforts under Smithsonian X 3D. Check out their 3-D model of Abraham Lincoln’s Lifemask. The viewer allows users to zoom and pan to incredible detail. A virtual tour created by Smithsonian staff walks the user through 12 text panels of contextual material. There are even individual annotations on the model itself to point out specific details. The Smithsonian provides downloadable data of the Lincoln life mask for use in your own systems, including a 3-D printer ready model. You may not be able to visit the Smithsonian in DC to see the life mask in person, but with access to a 3-D printer, you can have an accurate model in your hands.

The Process

In this section, I hope to demystify the photogrammetry process for others by demonstrating and documenting a specific project. While the technology is more accessible than ever, I recognize that the equipment, expertise, and time required to create a 3-D model may not be feasible for every course. See the Activities section for more ways to incorporate 3-D material into your class.

To create a 3-D model of a 19th century vase, I collaborated with Dave Pfaff (IQ Center Coordinator) and Ron Fuchs (Curator of the Reeves Collection). We selected one of the Uncle Tom’s Cabin vases, previously covered in a tookit, in order to show an alternate approach to the same object.

At its most basic, the photogrammetry process consists of selecting an object, photographing it in optimal conditions, then processing the digital images in specific software. The results are a 3-D model and precise measurements of the object.

We photographed the vase in the IQ center to take advantage of the professional lighting and equipment. It takes approximately 100 photographs, shot from every angle possible, to produce a quality model. The Uncle Tom’s Cabin vase proved a challenging subject to photograph. The intricate decorations create shadows on the object – some help show the relief while others obscure details. We minimized shifting shadows by keeping the lights and the object stationary. To suppress any glare or reflection caused by the glaze, we used a polarizing light filter. The filter keeps out the light that might bounce off the object. Finally, we added small stickers to the back of the vase to help the software model the white, untextured surface.

The IQ Center staff put together this time-lapse video of the photography process.

 

 

To create a 3-D model from the digital photographs, we used software called Agisoft PhotoScan. This software is proprietary, but an educational license is available. The first step is masking, or deleting the background from the images so only the object remains. Next, the photos are aligned to create a point cloud and a mesh of the object. This allows you to preview the shape and outline, making any adjustments to the model if need be. Only after the shape of the model has been built do you apply the texture layer of the digital images. If you find problems, you can actually edit the texture layer as a flat image. For example, Dave removed the stickers from the texture layer and filled in some holes in the model.

 

 

Once the model is complete, it’s ready for export to other systems. We imported the model into a virtual reality environment where we could manipulate the object with hand controllers. This is a fantastic and immersive experience for those with the equipment, but there are other ways to share your model with wider audiences. We uploaded the vase to SketchFab, a platform for publishing and sharing 3-D content. Our model can be viewed in a web browser or Google Cardboard. Google Cardboard is a cheap and accessible way to experience sterescopic objects or environments with just a piece of cardboard and a cell phone. You can even check out a Google Cardboard at our library.

 

Uncle Tom’s Cabin Vase v3c2
by IQ Center

 Activities

Even if a full-scale photogrammetry project isn’t feasible for your class, parts of the process can be extracted to cover a variety of topics related to objects and material culture. These activities will use the Uncle Tom’s Cabin vase as an example, but you could select or create your own objects to suit your needs.

Compare and Contrast

Give students the opportunity to view the vases in person at the Reeves Center (ideally with an introduction by Ron Fuchs) and the 3-D models through the browser, a VR system, or Google Cardboard. Students can reflect on the experience in class or in writing using the following guiding questions:

  • How were the two experiences different? How were they similar?
  • What is gained or lost by experiencing the object in person? As a 2-D image? As a 3-D model?
  • Which viewing option provides the most access to largest audience?
  • How might different audiences benefit from different viewing experiences?

Annotation

SketchFab allows users to add annotations to specific points on their own objects. Have students work individually or in groups to compose annotations for an object. Consider the following:

  • How many annotations is appropriate for your object?
  • How much text is approrpriate for each annotation?
  • What writing style should you employ? Who is your audience?

Photogrammetry with Your Phone

There are several apps on the market for doing photogrammetry on your phone, including 123DCatch, Trinio, or Scann3D. Have your students use one of these apps to create a model of an object then reflection on the experience.

For example, students in a Digital Humanities class used photogrammetry to create this model of the Recumbent Lee statue in Lee Chapel. This model provides a view of the statue that is not available from walking around the statue.

Other Ideas

  • Use photogrammetry as an opportunity to discuss proper object handling, storage, and preservation. Many students have never been given the opportunity to handle historical, valuable objects.
  • Use photogrammetry as an opportunity to teach photography practices and skill.
  • Because of large digitization projects, it’s easy to assume that everything is online. Have students identify local objects or collections that have not been made available online in a digital format. Students could write a pitch justifying that object’s digitization in 3-D form.
  • Go beyond objects. What spaces could be modeled in 3-D or VR? The space could be real (see Encyclopedia Virginia’s photospheres project) or imagined (Professor Wan-Chuan Kao’s Hotel Orient course). What cultural heritage site would you select to be saved by CyArk?

Resources

Photogrammetry

Objects

Local Resources

Articles

 

Bio

Mackenzie Brooks is Assistant Professor and Digital Humanities Librarian at Washington and Lee University. Prior to her current position, she worked as Metadata Librarian at W&L and at the Loyola University Chicago Health Sciences Library. As a member of the Digital Humanities Action Team, she advises faculty and students on best practices for metadata standards in digital humanities projects. Additionally, she teaches undergraduate courses on scholarly text encoding and digital humanities.

Dave Pfaff is IQ Center Coordinator, ITS.

Ron Fuchs III is the Curator of Ceramics and Manager of the Reeves Center.

License

This lesson was created by Mackenzie Brooks, Assistant Professor and Digital Humanities Librarian at Washington and Lee University in Lexington, Virginia. This lesson can be used or adapted by other educators for educational purposes with attribution to Brooks. None of this material may be used for commercial purposes. Copyright of original artworks belongs to the artist and/or university. Please contact Andrea Lepage for information about the lesson or the Teaching with UCAH Project: lepagea@wlu.edu or (540) 458-8305. Toolkit Lesson “Photogrammetry of Uncle Tom’s Cabin Vase” by Mackenzie Brooks is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.

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