As stylists transition to digital designs with fewer physical prototypes, they are seeking more realistic real-time graphics. Honda and PSA Peugeot Citroën have each developed programs that let them do more digital designs for overall vehicles and human machine interfaces (HMIs), respectively.
At the recent Nvidia GPU (graphics processing unit) Technology Conference, Honda explained how stylists are reducing the number of clay models of vehicles by using software that renders images that offer realistic visuals that change as materials and lighting are altered. PSA Peugeot Citroën engineers described a system being used from early concepts through the final design phase of digital display system development.
“During the styling phase, movies must be produced to illustrate the HMI concept and/or tools that are needed to simulate in real-time embedded systems,” said Alain Gonzalez, Workstations Graphics Technology Expert at PSA Peugeot Citroën. “During the design phase, the final HMI must be simulated with the interior environment in order to visualize reflections on windshield, color, and trim integration, embedded display defaults and also to validate the usability of the HMI.”
With the virtual prototypes, stylists and ergonomic specialists can change materials and viewing angles to see how minor alterations can impact HMI readability. The models hold data that let these developers make changes based on the capabilities of electronic controls and displays as well as user requirements.
“We can simulate different intensities and different points of view to see if factors are good or not good for drivers,” Gonzalez said. “We can also change the size of the driver, altering the viewpoint to see whether all people see the same thing.”
When these simulations are realistic, there is less chance that changes will be required late in the cycle when physical prototypes are completed. That is especially important in HMIs, since many of the parameters such as color and lighting intensity are subjective. Virtual prototypes are helping reduce the number of prototypes that must be built.
“We’re reducing the number of physical mockups we need, but we still need physical mockups of digital displays. There’s still a lot of trial and error in HMIs,” said Benoit Deschamps, Imaging Solutions Team Leader at PSA Peugeot Citroën.
Honda has taken a different approach, focusing on full-body design. The automaker put together hardware and software that lets vehicle designers change viewpoints, change materials, and examine what’s behind the skin.
“For computer-graphics-based design, we need physically accurate results, not just artistic representations,” said Daisuke Ide, System Engineer at Honda R&D. “We also need real-time performance. To accomplish this, we developed rendering software solution called TOPS.”
TOPS is a real-time automotive appearance evaluation for non-prototype design that was used in the development of the Accord and Fit. This focus on production vehicles means there is a strong focus on realism.
“When we go forward from conceptual design, we need images to look real” Ide said. “The images need to have the properties of real materials. The software includes the environmental effect on materials. Various material alternatives can look completely different.”
The software with the TOPS program includes Dassault Systèmes’ CATIA tools along with software developed by Honda. It runs on systems augmented with Nvidia’s K40 accelerator boards, which use parallel processing clusters to handle real-time graphics. That combination lets designers view vehicles on large screens in much the same way that they now examine clay models and physical prototypes.
“When humans judge appearance, they’re always on the move,” Ide said. “They need to move and see how body reflections differ. Along with the ability to move, people also want to be able to zoom in and check the details.”
The ability to change viewpoints, lighting, and other parameters makes it easier to alter products earlier in the design cycle when it is less expensive to make changes. When designers can change lighting angles as their viewing position, they can spot issues like reflections that can be difficult to perceive.
“Stylists are very conscious of small reflections,” Ide said. “On one iteration of a taillight design, they saw that the red reflected onto the white lights. They altered the angle of the glass to eliminate that reflection.”
The Honda tools also let design teams look inside and see what’s beneath the surface. All components in the vehicle are accessible, so various experts can examine their section of a design by pulling off layers to see a cutaway view. Each layer of these cutaways includes all the components on that section. That’s helpful as designs move into production.
“Being able to see real-time cutaways is very important for manufacturing,” Ide said. “They can see if all the parts are correct.”