12/1/2000 | 8 MINUTE READ

Being There

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When it comes to computers for design and engineering, General Motors probably leads the auto world (given its size, this speculation is not particularly risky). Its silicon, software and smarts are being put to good use as its designers and engineers are now moving from the 2D images on screens and clay models to the seemingly 3D world of virtual reality.


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Objects have their benefits. But they also have limitations. But what to do when you are designing objects yet want to minimize your limitations.

To say that the auto industry has embraced computer-aided design (CAD) is to make about as bold a claim as to say that moviegoers have embraced popcorn. Regardless of which of the world's OEMs it is (there is no geographic limit), regardless of how they describe their digital design domain (many companies tend to be as imaginative in this regard as they are in their vehicle platforms), the car makers employ CAD because they all believe in the power of advanced mathematics to make better vehicles more efficiently... but then there is the utilization of material that has been used for at least as long as homo has been sapient: clay. Designers make clay models of their vehicle designs. Sometimes the models are full-size. Sometimes there is a scale model (often one-third size). According to Randall C. Smith, staff research scientist, Vehicle Analysis and Dynamics Lab, GM Research and Development Center (Warren, MI), he learned something about the importance of clay so far as designers are concerned, even though he is a computer scientist: it's sheer physicality. The clay model is there. An object in the design studio. Something that can be walked by from various angles. Something that is there in the morning and there at night. Something that can be assessed as an object. Smith talks about "soak time." Over a period of time, the designers, platform engineers, executives, and other interested parties who interact with the model are better able to perceive what are perhaps anomalous aspects that they would otherwise not see on a CAD screen... no matter how big the screen is. "We kept building bigger and bigger displays," Smith says. "People wanted to see them [the vehicles being developed] full sized." But he notes that there are some "fundamental perceptual issues." The thing is this: even though the rendering on a CAD screen, even a BIG screen, might be almost trompe l'oeil photo realistic, it is still in a comparatively contained space, one described by the dimensions of the screen. The clay model, on the other hand, is there, out in the environment, not in a separate plane of space, as the CAD digital model is. Even if a car is displayed on a typical screen 24/7, the same sort of soak can't occur with CAD... at least not until Smith and his colleagues are done with it.

The scientists and engineers have developed custom software called "VisualEyes." They are now at version 4.0. As Smith points out, "This is not research code—it's not shaky. It doesn't break all the time." They've worked exceedingly hard at making this software capable of providing images that are high resolution, stereoscopic and full-sized. This is virtual reality (VR). It is kicking up CAD to a whole different level. Way up. Larry Peruski, who works with Smith, said that designers "need a full-size model to use their intuitive sense of depth and curvature. If you put a six-inch cube up there [on the screen], you ought to be able to walk right up to it and make sure it's six inches." The images appear to be real. As Smith remarks, "You can't make decisions based on a cartoon."

There are two basic approaches to displaying the information. One is on the aforementioned screen, which is a huge rear-projection unit that, in the case of the GM Design Studio in Warren, is of a width that dwarfs what you are likely to find in a Cineplex. The other display is called the "CAVE," which stands for "Cave Automatic Virtual Environment." In the CAVE, the images are projected on three walls, thereby providing the viewer with a sense of being in something.


virtual reality
Virtual reality is being used for more than just concept design work at GM. At the GM Metal Fabricating Div., engineers are using the technology to better understand the stresses and strains that are brought to bear on a panel after it has been formed.

The hardware for driving the images consists of Silicon Graphics Onyx2 computers. In the lab, for example, the hardware is setup in so that there are what amount to four workstations driving the images for the CAVE. Because there is a need to rapidly redraw the images so that the viewer has the sense that she is actually looking at something even though she moves her head from point to point on the object (there is actually a buffer required to allow perceptually seamless transitions from one view to the next), the data-crunching capability of the hardware is essential.

To achieve the 3D effect, viewers are fitted with a set of glasses that have liquid-crystal lenses. Essentially, the glasses open and shut very rapidly; there is no massaging of the data, but the math models displayed are perceived at two slightly different views, thereby providing the sense of depth.

With regard to the software, data from both Unigraphics CAx software and fromAlias rendering software are loaded into VisualEyes, and transformed. One of the objectives of the development was to make the system useable by someone who doesn't have a Ph.D. in computing. (GM is passing VisualEyes technology to Engineering Animation, part of Unigraphics, so that deployment throughout GM's design organization will be facilitated, as the company is familiar with creating interfaces that can be used by the engineering community.)


To talk about leveraging global resources is one thing. To effectively do it is quite another. VR can be a powerful lever.

The clay model is there. Which means that it is in one place. But GM is doing global product development. There are designers in different time zones. The temporal part can be dealt with (by having some people working at odd hours). The spatial part is not readily handled. If the clay model is in Warren, it is, obviously, not in Russelsheim, Germany. Certainly, there is the possibility of video conferencing: the model is Warren and the image is sent, in real time, to Russelsheim. But this means that the people in Russelsheim are looking at the object on a screen. Nuances are, perhaps, not noticeable. Which is not the case with the VisualEyes system. (Remember the six-inch cube?) GM is on track to create 19 VR design studios on four continents. "We flick a key here to rotate the model, and they see the same thing in Germany," says Don Siefkes, manager of the VR Studio at the GM Design Center in Warren. He adds, "It just blows you away."

Hitting the wall without breaking bones. Stamping metal without causing tears.

Although virtual reality provides a fairly good simulation of, well, real reality (while sitting in a simulated cockpit behind the steering wheel, when I was getting out of the chair I instinctively tried to avoid whacking my legs on the steering wheel), it facilitates views unlike any that a person would be able to achieve in reality.

For example, there is a view that is sometimes used during vehicle crash simulation. Obviously, no one is going to sit in a real car and drive it into a brick wall in order to perceive what happens during a crash. But not only could a person sit in a VR car and see what happens when that car hits a VR wall (clearly, the engineering information that is behind the simulation is such that there is useful data, not just clever animation), but they've actually set it up so that the engineer who is running the crash simulation virtually has his head in the middle of the vehicle's hood so that the perception of the deformation is up close and personal.

And beyond simulating accidental deformation, they are using VR at the GM Metal Fabricating Div. to get a better sense of what happens during the metal forming process.

Whatever the weather: viewing cars in full comfort.


projected images
Although it looks like a driver behind the wheel–and although that person senses a vehicle's interior–it is actually an image projected on three screens.

Jeffrey Stevens, manager, Global Styling and Virtual Reality, Virtual Reality Center, describes the VR Center as being "equivalent to a digital patio." Which is no small thing in the world of design. The patio is the place at design centers where the car is rolled out (or if it is a non-rolling model, carried out) so that the full-sized object can be seen in the light of day, the way that it will when it emerges from the factory (assuming that it gets the green light for production). Reflections, proportions and other aspects are all there, visible.

The digital patio is in some ways more efficient than the actual patio. For one thing, the sun can be arced across the "sky" much more expeditiously in VR time than in real-world time. For another, the weather can be modified with keystrokes.

So far as the vehicles go, colors can be changed in what amounts to a physical blink of an eye. Vehicles can be rotated so as to provide views that couldn't be attained even if the car was hooked to a crane in the patio.

A little 'imagineering' for GM executives—the guys at Epcot don't have all the fun.

One benefit of the VisualEyes system that isn't stated but must be a part of it is simply one of the coolness factor. Let's face it, although things like in-car navigation systems are certainly (sometimes) impressive, and even though some concept cars that are built in full-scale by model builders are undoubtedly appealing, the really high technology that the engineers and scientists are working with every day tends to be comparatively transparent to the executives in charge. That technology may be so high that it is of interest only to those who can recognize the cleverness of what they are up to. But with virtual reality, GM executives have a technology that they can become involved with that is as cool as anything that anyone else has: Disney's Michael Eisner has nothing on GM's Rick Wagoner in this case.


Hand holding a crystal ball

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