Digital dresses

Scissors, needles and mannequins may now be relegated to the dustbin of the clothing industry. Fashion designers are increasingly designing their new collections digitally - with simulation software.

"[Clothing] is a complex material - different to steel or other solid materials," says Jörn Kohlhammer at the Fraunhofer Institute's Computer Graphics Research Center in Darmstadt, Germany.

"Textiles have their own structure. Depending on how the fibers are processed, and their elasticity, the material will fall differently or pull differently when it's moved."

From threads to textiles

The computer scientist is presenting the new software, which he and his colleagues developed, at the IGD stand at the 2014 Hanover Trade Fair.

It's already in use by large clothing companies.

To ensure things are as lifelike as possible, the simulation of the individual textiles begins with the fibers woven into them.

"Whether I've got denim or silk naturally makes a world of difference," Kohlhammer says, tugging at the top of an onscreen, digital dress. He tosses the garment back and forth with the cursor. It twists and folds, and moves as it would in the real world.

Silk, not linen

"In motion, you see a very soft material here. We immediately have a sense of the fabric - in this case it's a velvety type of material," says the computer scientist. "If it were denim, it would be a much flatter image. The folds here, with the shadows, for example, are extremely important for the designer to be able decide whether they're going to get the draping effect they want or not."

Kohlhammer can also change the color map of the individual fibers.

"That gives a very realistic picture of certain textiles," he says.

When he renders the "behavior" of an entire garment, the computer model is simplified. Rather than calculate every single fiber, the software calculates the material behavior as a whole.

"If we didn't do that, we wouldn't be able to pull up quick and fluid real-life simulations."

Just like a tailor

A designer's draft begins as it would at a classic tailor's - with a pattern.

Based on the cuts of that pattern, the computer renders the swatches so that they appear as they would on a real person.

Kohlhammer directs the cursor to the individual seams, which he "sews" together virtually.

"The designer changes individual lines at the borders, pulls them together and defines the seams. It is important information for the simulator, so it knows how individual parts have to be sewn," he says.

On the monitor, fabric placed piece by piece on a torso becomes an entire dress.

"That's a very important step in 3D, real-time simulation. When the simulator pulls the seams together, I get a real-time, moveable textile."

Next step: Fiber-reinforced components

But Kohlhammer and his colleagues don't plan to stop at simulating textiles.

His goal is to transfer the company's "know-how" into completely different product areas, albeit those related to fiber behavior.

For instance, it could be used to make industrial components with fiber-reinforced plastics, such as carbon, glass fiber or viscose.

The software could also come into play in engineering projects for the modeling of aircraft and ships, says Kohlhammer, or even in the development of car tires.