A room-filling parametric design makes its way from the classroom to Austin’s famous music festival.
When Kory Bieg and his students at The University of Texas at Austin School of Architecture began working on Caret 6, they had no idea that it would wind up at this year’s South by Southwest (SXSW) music and arts festival. But the rippling, room-filling installation soon took on a life of its own. Within months, Bieg’s undergraduates—who had little previous exposure to digital design—had designed and fabricated Caret 6, and assembled and disassembled it twice, first at the TEX-FAB SKIN: Digital Assemblies Symposium in February, and then at Austin’s most famous annual gathering in March.The installation features a central catenary vault with two vaults to either side, plus a cascading front face. (Kory Bieg)
Caret 6 developed out of a research studio taught by Bieg, who is also associate director of the regional digital fabrication and parametric design network TEX-FAB. Selected to chair TEX-FAB’s annual design competition, Bieg knew that he would soon face a problem: how to display the winning entry in a gallery much larger than it. He put his students to work on a solution. “The idea was to create a kind of counterpoint to the winning entry. [We] needed to fill space,” said Bieg. At the same time, the studio would teach the fundamentals of digital fabrication. “It was really just an experimental exploration of what these tools could produce,” he said.
Caret 6’s white and grey diamond-shaped cells cascade from a central catenary vault with three column bases. Two secondary vaults project from either side. The front face of the structure flows down to the floor. “The idea is, we didn’t actually know who the winner [of TEX-FAB: SKIN] would be,” said Bieg. “We wanted to design a ground surface that was modular so that we could replace some of the cells with bases for their models.”For Bieg’s students, the project was a chance to experiment with digital design tools including Grasshopper and Kangaroo. (Kory Bieg)
The 17 students enrolled in Bieg’s course first created individual study models of aggregations and weavings amenable to digital fabrication. In an internal competition, they narrowed the field to three. Bieg broke the studio into teams, each of which experimented with creating volumetric versions of the designs. In a departure from typical parametric installations, Bieg and his students decided to stay away from patterns that gradually expand and contrast. “Our interest was not [in] doing subtlety, but local variations that are quite abrupt, like going from a large cell to a small cell,” said Bieg. “So part of that was a result of the way we structured it. Instead of aggregating cells, we designed a series of ribs.” The primary ribs form the vaults’ seams, while the secondary and tertiary ribs divide the structure into asymmetrical pockets.
Halfway through the semester, Bieg called Alpolic Materials, whose Aluminum Composite Material (ACM)—a thin polyethylene core sandwiched between two sheets of aluminum—he had worked with on an earlier project. Alpolic agreed to donate supplies for Caret 6, “so we refined the design according to the material we had,” said Bieg. He also drafted students from UT engineering to calibrate the structure’s thickness, scale, and cantilever distances. “It kind of just evolved from these different processes coming in,” said Bieg.The students fabricated Caret 6 out of Alpolic ACM. (Kory Bieg)
Back in the studio, Bieg’s students used 3ds Max for form studies and Kangaroo, a Grasshopper plug-in, to fit the tessellated diamond pattern to the vaults. They also used Grasshopper to develop an assembly system of binder rings, bolts, and o-rings. Bieg and his team fabricated the installation using UT’s CNC mill. They cut the vault pieces out of Alpolic ACM. The elements closest to the floor are polypropylene, while the intermediary pieces are high-density polyethylene.
The students assembled and disassembled Caret 6 manually. At first, they tried working with a QR-code system, scanning each component to determine its location. When this took too long, they projected a digital model of the form on a screen, then called out each piece by number. For SXSW, where they had only six hours for assembly, they subdivided the structure into sections that could be quickly recombined on site.
Caret 6 travels to Houston in September, where it will rejoin the entire TEX-FAB: SKIN show. But while the installation has already moved beyond its original context, Bieg insists that it remains rooted in the SKIN competition brief, which focused on building envelopes leveraging metal fabrication systems. “[Caret 6 is] not really a program per se, but more of an experiment about the same concepts that were part of the exhibits at TEX-FAB,” he said.Bieg and his team assembled and disassembled the structure by hand. (Kory Bieg)