Designing the A1 Sportback

What happens when the power of 4300 laptops is combined with human craftsmanship?

Binary code meets human instinct – the process of designing a new models remains a combination of digitisation and traditional clay models – with a modern twist.

Charlotte Seybold

12 November, 2019

The design process of a series model at Audi takes around four and a half years

Curiously, I open the door to the new C3 studio in the Audi Design department. Bright light streams from the neon lights, electro pop gently wafts from the speakers. The room is full of designers, 3D CAD-form designers and clay modellers. CAD stands for Computer-Aided Design, meaning that the design phase is helped along by automated, digital processes. And right in the middle of the huge model studio is the Audi A1 Sportback – made from light-brown clay, a special industrial plasticine mixture. Made just for me. 

But why is there a need for a physical model during the digital design phase? Does digital design need to be made tangible?

Markus Gleitz, the head of the Exterior Design CAD/Technology department, explains how the design process works: 

“The design process of a series model at Audi takes around four and a half years. Prior to beginning the digital design phase, we work together with experts from technical pre-development and marketing,” he says.

“In the initial design phase, we define the first technical frameworks such as the bonnet’s elevation or the wheelbase.” 

Within these requirements, the designers can let their creativity run free in the drafting phase. Sketches are made either traditionally on paper or digitally on a tablet. After the drafting phase, it’s time for the digital design phase, known as the C3 process for short – and that’s what they’re working on today. The three ‘Cs’ stand for CAD (Computer Aided Design), Concept and Clay shaping. 

In the C3 process, CAD form designers transform the designers’ sketches into a 3D CAD data model. The data is displayed photo-realistically in real-time on the Powerwall – a large wall covered with LED screens. Digitisation at its best. Soon afterward, a milling machine uses the data to create a physical clay model. It’s the perfect combination to make digitisation tangible. 

Designers and CAD formers use the Powerwall to evaluate the data on a 1:1 scale and check its consistency. Due to the high power of the computation cluster — essentially a huge computer network — designers can see immediately how their changes affect the digital model. 

The 3D car is displayed photo-realistically and in real-time and the 3D software, lets designers visualise any changes in terms of proportions, overhangs or shadowing very quickly. This lets them detect possible discrepancies before the clay model is built — in contrast to their previous working methods. 

Even the reflections in the paint are photo-realistically animated. The visualisation software uses ray tracing, a vector-based rendering method that calculates optical effects such as light, shadow or reflection using correct physics and displays them accurately, taking into account the time of day – for perfect car design. 

Even the reflections in the paint are photo-realistically animated

The computing power of the cluster is equivalent to around 4,300 notebook computers

The computing power of the cluster is equivalent to around 4,300 notebook computers and even dynamic driving footage and driving simulations of the models can be calculated and displayed on the Powerwall. Without the Audi A1 Sportback ever having been on the roads of Barcelona, I can watch it gliding along Spanish streets in the early evening — at 7pm sharp. But of course, you still can’t touch it. 

Is that the reason that the Audi A1 is still shaped from clay? 

“No, not only because of the haptics,” designer Harald Riedlmüller explains. “The Powerwall gives a really good impression of the vehicle. But nothing quite compares to the feeling of standing in front of a real model. Only then is the perspective realistic and lifelike for the human eye.” 

The digital possibilities facilitate the production of life-size models. By constantly comparing the Powerwall with the clay model, the milling machines automatically change the clay model to reflect changes in the 3D CAD data. 

That is, as long as enough material is available. Before the machine shapes any new additions, fresh clay has to be applied and that is still done by people.

The Audi designers also have another tool available – VR glasses. 

“With the VR glasses, we can take a look at the model in 3D in a virtual simulation. The lifelike display of design models becomes even more realistic”, explains Harald Riedlmüller. “In the following years, VR applications will become a standard tool in the design process”, Markus Gleitz adds. But VR glasses will be able to do even more. 

In the ‘holodeck’ one floor higher, Audi designers are researching new virtual display options. There, with the help of VR glasses, they can view their 3D CAD models in a seemingly real virtual world. Multiple users can log in simultaneously and see each others’ avatars. In the foreseeable future, VR glasses will make it possible to hold design meetings across multiple continents. Then Audi designers from Ingolstadt, Beijing and Los Angeles could meet up as avatars in a virtual studio. And that’s when digital data will come to life – wired gloves with haptic feedback will make it possible to digitally touch the virtual models – and then you will have digitisation you can touch.

In the foreseeable future, VR glasses will make it possible to hold design meetings across multiple continents