Virtual forms for buildings and society
Faculty present findings at AAAS meeting

Sarah H. Wright, News Office
February 23, 2006

Two MIT faculty members presented research and offered innovative
perspectives on their fields at the annual meeting of the American
Association for the Advancement of Science (AAAS) held February 16-20 in
St. Louis.

John Ochsendorf, assistant professor in the Building Technology Program,
and Henry Jenkins, director of the Comparative Media Studies Program,
presented papers at the AAAS meeting, which was attended by more than
6,000 people, including 900 scholars and scientists. The meeting's
overall title was "Grand Challenges, Great Opportunities."

Ochsendorf provided a press briefing in a symposium, "Arches: Gateways
from Science to Culture," which was part of a daylong series called
"Beyond Pi: Grand Challenges in the Mathematical Sciences."
Optimizing architectural forms

A structural engineer specializing in architectural and construction
history, Ochsendorf presented a virtual design method that has been
extended in novel ways by a team of architects, computer scientists and
engineers at MIT.

The method, known as particle-spring systems, is a three-dimensional
design tool that was originally developed by computer scientists for
creating graphics such as character animation and cloth simulation. For
example, particle-spring systems produced the clothes "worn" by virtual
characters such as Yoda in "Star Wars Episode III: Revenge of the Sith."

The interdisciplinary MIT team proposes to employ particle-spring
systems dynamically: They are using the software, which models the
gravitational load on a given shape's exterior, to find a structure's
most efficient form and to allow the architect or engineer to interact
with the form-finding program while it is still running.

When it is running, the team's software program displays arching lines
that look like white daddy-long-legs spiders, delicately dancing on a
black field as they seek efficient forms. The program can also be used
for modeling structural elements, such as trusses, slabs and beams.

Historically, finding and creating new structural forms was accomplished
by painstaking physical means. Antoni Gaudi, Spanish architect and
designer of the chapel of Barcelona's Colonia Guell, devoted 10 years to
a "hanging chain" model made of weights on strings that would serve as
an upside down version of the efficient arched forms he sought.

MIT's virtual method, Ochsendorf said, is as straightforward as Gaudi's
physical method for exploring and testing new forms, but it uses time,
materials and money more efficiently.

"Using the particle-spring approach, a three-dimensional structure such
as a cathedral can be created in only a few minutes. Most importantly,
the user can change form and forces in real time while the solution is
still emerging," Ochsendorf and Axel Kilian (Ph.D. 2006) wrote in a
recent paper, "Particle-Spring Systems for Structural Form-Finding."

Ochsendorf also envisioned MIT's particle-spring systems method being
used to analyze and illuminate historic masonry methods (these secrets
were closely guarded by guilds) and to support sustainable modern
building practices by discovering more efficient -- and
less-resource-consuming -- structures.