Creating 3-D Object Models

posted on 22 Mar 2017 16:59 by swang
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This week in the Bard Graduate Center class “The Inca and their Ancestors: Andean Objects, Technologies, and Issues of Conservation,” Alicia Boswell, Mellon “Cultures of Conservation” Postdoctoral Fellow, and her students took the next steps of their class project to create 3-D object models of ancient coastal Peruvian earthenware held at the Metropolitan Museum of Art, found with the famous mummy bundles of the Paracas culture (800 BC – 1 AD). The class met with Dr. James Doyle, Assistant Curator in the Arts of Africa, Oceania, and the Americas, to get an inside look at the unique objects – and issues – of the recently installed Paracas exhibition. Historical context in hand, the group then headed behind the scenes to dive head-first into their mission to photograph a set of Paracas ceramic vessels with the help of Jesse Merandy on behalf of the BGC’s Digital Media Lab. The class expects, by the end of the semester, to create a fully contextualized project that combines their understanding of Paracas culture and ceramic technology with recreated 3-D images of the objects themselves.

These Paracas vessels come from the Metropolitan’s Nathan Cummings collection, some of which are nearing three millennia in age. The selected objects were originally made, however, over a span of many hundreds of years, allowing students to learn and chart the development of Paracas ceramic wares and styles, along with their change over time. At the beginning of the class period, Dr. Doyle pointed out some of these recognizable changes while speaking to the group at the permanent AAOA Paracas exhibit, and it immediately became obvious why these ten vessels were chosen to illustrate the evolution of Paracas style with their different decorative techniques, including post-fired painting, negative resist slips, and incised drawings. Colorful incised bird and cat forms adorned a number of ceramic objects, while two-tone negative resist dots and fish played over the surfaces of other small bowls – each technique demonstrating the precision and dexterity of Paracas makers over time.

Doyle, along with the class’s own research over the semester, stressed the fact that many of these forms and techniques existed simultaneously, and such forms and techniques were also shared along the Peruvian coast where these objects have been found. This same fact of transmission is also true for a number of the truly remarkable textiles on view in the exhibit, which range from small border fragments to large mantles. Each of these pieces is as visually and technologically compelling as the last, and they hold clues to the sociopolitical and cosmological traditions of the people who created them. Close analysis of the imagery reveals, as Doyle takes note, more than just the shamanic tradition of the Paracas culture; the textiles divulge references to other surviving physical objects of material culture, like hammered golden crowns and decapitated heads, and they also bring up new mysteries, such as why ancient Peruvians so consistently created designs in mirror images of one another. Moreover, analysis of the materials used to create the textiles provides further information on this little-known culture, such as what dyes were being used where, or when new resources came into production. This data can give important clues as to the chronology of manufacturing techniques in the area, and thus, the chronology of the people themselves, and such data can also illuminate networks of exchange, communication, and religious beliefs. Two examples of textile fragments from Peru can be seen in the accompanying images and are on display at the MET.

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Closeup of Paracas Border Fragment, Figures with Staves, Metropolitan Museum of Art 33.149.43, 4 x 19 in. (10.16 x 48.26 cm).
Photo by Emily Field.

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Close up of Feline in Paracas Embroidered Border Fragment, Cotton and Camelid hair, Metropolitan Museum of Art 1994.35.119, 16 1/4 in.
Photo by Emily Field.

Having gotten to finally see this collection of Paracas objects in person after six weeks of research, the class began the next phase of their visit, where each student took photos of two vessels in the Cummings collection for eventual 3-D modeling. In a private workroom, students split into pairs and helped each other by providing a backdrop while their partner circled their vessel, taking numerous overlapping photographs of the object from various angles. A set of these vessels is included here in images, one showing the pot in front of its backdrop, the other surrounded by black and white markers. Both these markers and the overlapping images are important for the modeling software, Agisoft, to be able to recognize and create a digital rendering from the compilation of angles. The photograph of Mellon Fellow Jessica Walthew gives an in-action impression of this process of capturing a vessel from all sides.

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Paracas Vessel with Handle, Negative Resist and Post-Fired painting, Metropolitan Museum of Art - 64.228.142, H. 10 7/8 x 7 ¼ in. (27.62 x 18.42 cm).
Photo by Emily Field.

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Photogrammetry photo, Bottle, Feline Face, Metropolitan Museum of Art 1976.287.17.
Photo by Emily Field.

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Mellon “Cultures of Conservation” Fellow Jessica Walthew preparing to take photos for photogrammetry.
Photo by Emily Field.

In addition to walking around the objects, the group used another method for taking photos of the vessels for 3-D rendering, utilizing a software program called PAMCO to control an automated turntable on which the ceramic objects were placed. The turntable rotated at preset intervals while a camera, set on a tripod and synced with the software, took photographs at each revolution. Individuals in the class hope to work with both sets of photos from each of the two methods to create 3-D models in Agisoft, in order to identify the benefits and challenges that come with either technique and to develop a better understanding of photogrammetry. Stay tuned until the end of the semester as we discover the secrets of Agisoft and work towards our final collaborative digital exhibition.

Emily Field

Emily Field is an MA student at Bard Graduate Center.

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