Issue: Volume: 24 Issue: 6 (June 2001)

Part to Art

By Jenny Donelan

Virtual prototyping has brought sizable time- and cost-savings to the automotive industry. Now, in a demonstration of the synergy that computer graphics is bringing about among traditionally disparate areas of manufacturing, the same CAD files that streamline car design are serving to create promotional materials.

Using a new conversion and rendering process, Burrows, a UK-based design agency, is turning CAD assemblies into glossy, photorealistic 3D models, ready to roar across the television screen or grace the pages of technical brochures-all before the cars have even been physically prototyped.

The process, which Burrows took three years to develop, is called NVisage, and comprises a mixture of off-the-shelf software, hardware (including Advanced Rendering Technology's RenderDrives), and proprietary code. "We like to describe NVisage as a digital camera that takes photographs of things that don't really exist," says Keith Harmer, head of 3D studios for Burrows.
With CAD manufacturing data provided by Jaguar, the Burrows design firm was able to create a photorealistic inside-and-out view of Jaguar's new X-400 sports sedan-before the vehicle was physically prototyped. (All images courtesy burrows nvisage)

Burrows first embarked on the NVisage project when client Ford Motor Co. asked it to produce a photorealistic 3D model early in a vehicle's design process. The de sign firm field-tested numerous products, but finally found the best solution was to develop its own turnkey system.

In order to get from CAD data to glossy brochure, Burrows artists must first obtain all the CAD model files for a vehicle-"every nut and bolt, every sprocket in the gear box," says Harmer. In the case of Ford, Burrows downloads the data from the car manufacturer's server. The data is then converted, using a proprietary process, to a 3D model, then rendered with ART's dedicated rendering hardware, the RenderDrives. The resulting product is a 3D model that is ready for a multitude of uses. "It's similar to a real prototype in that you can decide what to do with it: shoot photographic stills, or film it driving over a bumpy road, for example," says Harmer.

Because each component of the car is part of the NVisage model, the digital prototype can be used to illustrate the vehicle's internal structure as well as its shiny surfaces. In the case of the X-400, a new sports sedan that Burrows converted for Jaguar, the vehicle's all-wheel drive system was a key feature, and so details of that were featured in press kits handed out at the X-400's launch.

The advantages of such a system are best understood in relation to the methods that have traditionally been used to create promotional materials for new cars. In a height-and-angle study, for example, which is used to determine a car's glamour shots, the physical prototype is photographed from different heights at 5-degree angles, resulting in a 432-shot visual reference. The shots are posted on a wall so that management can choose the most appealing ones. This method has several drawbacks. The first is expense. The second is time-the height-and-angle study cannot be completed until a physical prototype is available to be photographed. And the last concerns human nature. Since individuals at Burrows would weigh in on the best 'hero' shots publicly-that is, in view of one another-one person's decision could conceivably affect another's.

For a height-and-angle study using the NVisage system, the Bur rows team now creates a QuickTime VR file from the 3D model that can be sent over the Web to personnel worldwide. Everyone weighs in on their favorite shots without knowing what anyone else has chosen. This way, says Harmer, "the company can get a better idea of what people really prefer."
Because Burrows obtained CAD files for every digital component of Jaguar's X-400, the firm was able to create marketing and press materials focusing on specific details of the new vehicle's interior, such as its front suspension (below) and V6 engine (ins

Once created, the NVisage model, which Harmer estimates takes about 45 person days to produce, is both a time and a money saver. For example, a single cutaway view of a car (one that shows a portion of the interior along with the surrounding exterior) in a traditional, illustrated style costs approximately $25,000. The same cutaway view of the 3D digital car costs approximately $7000, and is photorealistic as well.

For electronic distribution, the NVisage model is optimized for quicker transmissions. But otherwise, Burrows's goal has not been to reduce the CAD data, but to retain every bit of it in order to achieve the highest quality image. "The edge of a door, for example, has a very tiny radius," says Harmer, "but that CAD data is there [in an NVisage file]. If you were going to produce a model yourself, you wouldn't put any of that detail in, but it was all there for manufacturing purposes, and that is what leads to the photographic effect."

The huge amount of CAD data proved one of the greatest challenges to the development of NVisage. "It was a struggle for Burrows's 3D application to cope with it on the workstation," says Craig Wareham, marketing manager for ART. "We provided them with a bit of software that would help alleviate the problem while they were preparing that data for rendering, before it was sent over to the RenderDrives." From ART's point of view, says Wareham, the NVisage project was an opportunity to test the RenderDrive's capabilities. "We had designed it to cope with that scale of project," he says, "but it was certainly the first time that we'd actually had a customer push the system that far."
Connecting to a Ford Motor Co. server gave the UK-based Burrows access to all the CAD data for the company's latest Thunderbird model (top), including the engine (above left), powertrain (above right), and front suspension (right).

Harmer concedes that an NVisage model is not inexpensive to produce. But when done, the savings add up. "Once you've got that 3D model," he says, "you can use it for so many things."

Jenny Donelan is Managing Editor of Computer Graphics World.

Advanced Rendering Technology ·
Burrows · Essex, UK