In the Italian Renaissance, artists seeking a more lifelike portrayal of the human figure went so far as to skin or dissect human bodies to better examine the muscles.

Mara MacMahon, who graduated May 18 with a Bachelor of Fine Arts in communication design from the Sam Fox School and a Bachelor of Arts in biology in Arts & Sciences at Washington University, continues this tradition but in a medium beyond the ken of the Renaissance masters.

She uses the anatomical knowledge gained from dissections to "rig" animated characters that pounce or flounce in a believable way.

"The character is initially modeled in a neutral pose," she says, "but it has to look great when it's running around. My job is to set up the controls so that the animator who wants a character to, say, extend an arm, can just click on the control for the wrist and pull the wrist outward and the other muscles will flex or extend realistically."

She chose WUSTL because she was passionate about art but also interested in medicine, and few schools are strong in both.

Here, she was able to dissect a dogfish and a cat in a vertebrate structure course offered by the Department of Biology in Arts & Sciences.

"A lot of art anatomy books you buy," she says, "it's all surface anatomy. You see the shapes and how things maybe fit together visually, but you don't understand how they work or what happens when you flex a muscle. So taking an anatomy class was very helpful to me."

After that, she arranged to shadow the medical students in their anatomy course. "I brought my sketchbook and drew as they dissected cadavers," she says.

As she was struggling to choose between medicine and illustration, a thrilling third possibility appeared. She saw a Pixar internship posted on Facebook.

Feeling not quite qualified for the internship, she waited a year to apply so that she could take an introduction to 3D animation class taught by Jon Navy, senior lecturer in the Sam Fox School.

"I later found out," she says, laughing, "that I was the only one who sent (Pixar) just a flatwork portfolio and no DVD reel of motion."

Navy thinks he knows why she got the internship. "Mara is fascinating to everybody in animation because her knowledge of anatomy is way beyond what they usually get. Do I dare say she's kind of a Leonardo? She's so strong both in science and in art."

MacMahon credits Navy and her communication design professors, Doug Dowd, Jeff Pike, and John Hendrix, for giving her the artistic chops she needed to succeed.

The Pixar internship turned out to be a crash course on filmmaking — lectures, demos, and a mini-assignment scheduled for critique by the end of the first week.

After returning to WUSTL, MacMahon kept momentum going by taking independent study with Navy and reaching out to the online community when sticky challenges arose.

In her junior year, she applied for an internship at Disney, telling herself that if she didn't get a summer job in film she would go to medical school.

By Commencement, she still had not heard from Disney, but that night, at midnight, Disney e-mailed an internship offer.

Of course she called her mom. And no she didn't wait until a civilized hour.

She was hired as the technical director responsible for constructing a character rig and establishing how muscle, skin, hair, fur, and clothing will behave.

She had direct access to top animation professionals at Disney and clearance to look at the character rigs for Tangled, an animated feature Disney had just released.

"I probably learned 80 percent of what I now know about rigging over the summer," she says.

She also learned how much work goes into film. Working flat-out full-time nonstop the entire two months, the team of 12 interns was able to pull together a super-short film in which Little Red Riding Hood's basket is filled and she sets off into the forest.

And when the mini film was screened at Disney, the professionals gave the interns a big round of applause.

Here is the demo reel she is currently sending around to studios: