Nike uses IRIS Explorer to design hi-tech footwear

Flexible and powerful computer visualization software is helping a world-famous sports and fitness company's 'R&D SWAT Team' look for technological developments that can take it into the future with improved products and processes.

IRIS Explorer's task at NIKE includes visualizing 300,000 data points smoothly, accurately, and quickly.

Bob Borchers, Research Manager, Advanced Technology, and his Footware Design and Development Group in Beaverton, Oregon are carrying out a corporate mandate to study promising technologies and major product opportunities at Nike, Inc. "We evaluate everything," Borchers says of his cross-functional team of computer programmers, biomechanics experts, and mechanical engineers. "The department looks at all opportunities from low-level technologies - computer tools that could help us design products faster to meet the needs of the individual, to new systems for how to fit a shoe."

With a background in mechanical engineering from Stanford University and a masters degree from a joint Harvard University/MIT program in medical engineering, Borchers' own research is in "foot-shoe interaction" - analyzing thousands of foot shapes, using that information to define the internal volume of a shoe.

Designing a shoe means creating various components - the outsole, midsole, and upper - and then fitting these components around a foot support unit called the last. Borchers and his team are interested in understanding and perfecting this shape which represents the internal volume of the shoe.

"Traditionally, the shoe last has evolved based upon manufacturing constraints," Borchers explains. "We are trying to take the opposite approach - having the last evolve through better understanding of foot morphology."

Today, Borchers and his team know that while the shape of the last somewhat resembles a foot, in some very important ways it does not. Much of the research they are doing - especially including the use of computerized visualization tools - is to get a better understanding of what the internal shape of a shoe should be.

Armed with a Silicon Graphics Indigo 2 Extreme desktop workstation with R4400 processor, four gigabyte hard drive, and 128 megabytes of RAM, Borchers uses IRIS Explorer an interactive 3D data visualization system to analyze data. The team's datasets range in size from four to 20 megabytes (based on foot scans producing 300,000 points in x-y-z spatial datasets).

"We involve IRIS Explorer (IE) in two very important aspects of our research," he says. "The first is for rapid application prototyping. When we want to try to test a new analysis algorithm - or if we simply want to do ‘what if’ experiments - IE gives us a fast and flexible way to pull together prototype code. The low programming overhead associated with IE is a big advantage to us. To a large degree, understanding our analysis results and the morphology of the foot requires fast and accurate visualization, and this is where IE delivers the second big benefit. Whether our data is from a laser scanner or a touch probe, IE consistently handles any dataset."

"We take great pains to make sure that whatever we're going to present will appear as a seamless dataset. And IE visualizes, renders, and rotates our data just that way."

"The flexibility of IE visualization tools - especially the Render module -is very important to us," he says. "We often want to flip very quickly through surface representations - solid, wireframe, point - Exactly what was that bump on the top of the foot that we just looked at? Is that an abnormality in the dataset? Or is that actually a growth on that person's foot? Cycling rapidly through a number of variations helps us to probe the dataset."

Borchers says that fitting shoes to feet is further complicated by the fact that feet change shape significantly during the course of the day - even over the course of an hour. "We may have two shapes of a person's foot from one day to the next, and they may be very different," he says. "With Explorer and the additional tools we’ve written for it, we can very quickly look at the two related shapes, compare them, and identify the differences between them."

The Render module displays geometry data. It is built using the Inventor Scene Viewer which allows a large number of different viewing paradigms. There are two major modes in Render - viewing and selection/picking. In viewing mode, the camera parameters can be changed, and users can toggle between a perspective and an orthographic view. Other features include a Fly viewer that simulates constrained flight through space, a Walker viewer for a walk-through allowing motion and a camera pointed with constant eye level, and a Plane viewer that lets the user manipulate the camera with respect to the viewing plane.

Part of the uniqueness of Borchers' task is that there are very few computer visualization tools that can do the same functions that the team asks IE to do. The problem, as he describes it, is that off-the-shelf tools expect to see fairly regular shapes and datasets. Feet, however, are amorphous, and they generally break the rules or assumptions that are made by mechanical engineering and CAD packages.

"Part of the uniqueness of Borchers' task is that there are very few computer visualization tools that can do the same functions that the team asks IE to do."

So Nike’s solution is to use IE to bring in datasets, and then probe those datasets with IE so that they can see the results in a visual, understandable form. Then they export the data to CAD packages only after it is fully understood.

For screen presentations, the team frequently will do screen captures, then embed them into presentations, documents, or feed them directly into a large format color plotter that can print images in cross section.

Because the Nike organization employs so many creative people who are visually oriented, top-notch visualization software is absolutely integral to communicating results. "The people that our team talks to could care less about whether I use a surface normal comparison or if I have 18 decimal points of precision," Borches explains. "They want to be able to understand what's going on at a gut level. The only way to communicate that is through visualization."