From idea to finished car: High tech and handmade finish in the Audi design

At the start you have a brilliant idea, at the end a harmonious, fascinating product. The design process reflects the connection between idea and product. Audi brings together the best of both worlds in its cars: The digital design manufactory combines state-of-the-art digital visualization techniques with superb handmade precision. The C3 process is the core element in the new design workflow. Thanks to photorealistic visualization in real time, the designers can already assess the design on the screen.

Audi is constantly rolling out new models and new technologies. So the designers’ challenge is to turn more and more design concepts into series-production models in less and less time. With more than 400 employees, Audi Design now has more than twice as many employees as in 2000. At the same time the team is processing five times more projects and is dealing with increasing technical requirements in vehicle projects. Design presentations and technical package specifications must be coordinated across the various disciplines. For this reason the Audi Design team has developed a new design process, which combines CAD (computer-aided design), 3-D visualization and traditional design model making as well as clay modeling. The result is high process reliability, a coherent design concept and greater flexibility for creative design ideas.

Portfolio and initial phase
Normally the design process at Audi starts around five years before the launch of a new model. At the start the designers create the basic design language and design characteristics of an entire model family. A joint technology matrix tends to form the basis for the design decisions in the basic portfolio phase. Here the designers together with colleagues from Sales and Technical Development are heavily involved in the company’s strategic product planning.

How well does a new compact SUV fit in with an existing midsize model? What derivations are conceivable and which make sense? This matrix of different requirements – segment, configuration, design, customer and market requirements – initially gives rise to several portfolio models. With these 1:10-scale models the subsequent package still plays a secondary role. These models primarily provide a first impression of a design theme in various vehicle segments, such as with a sedan, an SUV and a coupé. The models evolve on the basis of CAD data by milling Ureol plastic or with a 3-D printer by means of rapid prototyping.

The design process of a series-production model starts with the initial design phase. This phase lasts between three and four months. Here the Audi designers work in close coordination with the studio engineers, the engineers from concept development and the Sales experts. As a result they translate the rough technical layout into a 1:1 architecture model. The focus is on those variables which determine the volume and the proportion, for instance the wheelbase and the height of the engine hood or basic technology package and components, such as the position of vehicle sensors.

The 1:1-scale architecture model is milled from a dense polyurethane foam and then painted. The final exterior design does not play a role with this model. It provides designers with an initial comparison of their design ideas with the future product. The model also allows modifications to be evaluated which become necessary due to technical requirements.

Insights from the architecture model provide designers with a reliable basis for the subsequent sketch phase. As such, the exact technical specifications do not restrict the designers’ creativity, but rather guide the designers in the direction of what is technically feasible. Once the technical requirements have been clarified, the designers can give free rein to their creativity. Thanks to the precise technical specifications, the designers can produce suitable concept designs from the outset. The design they are working on comes to life faster than before; the design quality is even higher.

Draft phase
In the subsequent design briefing, designers and Sales experts develop a joint leitmotif in words and images. This entails fine-tuning the package information and the basic knowledge acquired thus far. Teams from Audi Sales, which analyze the market, competition and the customer expectations, provide important input. In the sketch phase, which lasts around two months, the designers traditionally work with pen and paper and digitally with electronic drawing boards. Several exterior designers work with each other in a spirit of friendly competition, normally seven for the interior, and eight or nine for the exterior. The best exterior idea makes it into the next process phase, the C3 process.

Digital design phase
The digital design phase is tailored to the concept of the new Audi Design Center. It consists of three components: CAD, concept, clay milling – or “C3 process” for short. The process delineates a new form of collaboration between CAD modelers and exterior designers. The CAD architecture model from the initial design phase provides the basis for the new design concepts. The CAD concepts appear in real time on the 1:1 LED screen in photorealistic quality and can be checked for their consistency and rapidly transferred to a physical 1:1 reference model.

“With the high-end visualization of the C3 process, I am confident I can already assess a design digitally,” says Marc Lichte. The high computing power of a computing cluster enables the latest design versions to be computed and presented photorealistically in a matter of seconds. The direct transfer of the digital design image to a physical reference model enables the photorealistic representation in the digital model and physical 1:1 volume model to be compared continuously. The clay reference model also serves as a physical basis for discussion between designer and CAD modeler and as a “three-dimensional sketchpad.”

The connection of digital modeling and clay milling in the C3 process facilitates faster development of the final design concept without compromising the quality of detail or decision-making reliability. The process also provides flexible, rapid reactions to change requests. As such, the new design process is an important contribution to the corporate strategy in terms of digitalization and sustainability.

The current computing power makes photorealistic representations possible in real time and allows design concepts to be assessed digitally. The new Audi Design Center offers the optimum conditions: Five LED walls with presentation areas of 5.5 meters (18.0 ft) up to 11 meters (36.1 ft) wide and very high resolution show new models accurately in every detail. The computing cluster is used jointly by Audi Design, Surfaces Development, in other words the interface between Design and Construction, and the data control model (DCM), and enables visual simulations of the design data in real time. This cluster consists of 480 interconnected nodes and its computing power is equivalent to the performance of around 4,300 notebooks.

The visualization software for the representation on the LED wall works in accordance with the ray-tracing principle. Using this vector-based ray process, optical effects such as light, shade, reflection and refraction are computed and displayed correctly from a physical perspective. Whether Barcelona on a sunny September day at 7 p.m. or Cape Town in January around midday with a cloudy sky – the software shows the new Audi models in every required lighting situation and in any possible backdrop. It reproduces precisely the depth of the paintwork and the degree of sheen of the surfaces.

The computing power enables virtual models to be viewed photorealistically in real time or also enables them to be rotated in various views or driven in various scenarios after a short animation time.

Thanks to the computing cluster, the designers can digitally add a wider side sill for a new model and immediately see the effect on the digital model: Changes in terms of proportions, overhangs and shadows can be visualized virtually instantly; any discrepancies are discovered well before the physical clay model is put together. Process reliability increases substantially as a result.

The 3-D visualization also provides dynamic driving shots and driving simulations. vDEV models (virtual Design Experience Vehicle) are created for this purpose. Thanks to their level of detail, these animated driving models already provide a virtual impression of whether a design concept is coherent and how it behaves dynamically in a virtual driving scenario. The vDEV models can, for instance, complete their laps on the Audi test track in Neuburg. All the physical circumstances are incorporated into the simulation, such as bumps in the road and body movements. In this way, all the design details can be checked for coherency on the driving model – from the shadow through to light reflection with different driving and weather conditions.

In the interior too, increased visual simulations enable the even more precise use of materials such as paints, leather and cloths. The further enhanced display quality will also allow final assessments on the digital model in future.

Audi’s C3 process combines the best of two worlds: The CAD milling machine is faster than its human counterpart, it works with accuracy down to a tenth of a millimeter, and it does not need any breaks. A CAD modeler develops the data model on the computer; the milling machine transfers their specifications to the clay model. The new Design Center houses 20 of these machines with swiveling milling heads.

In accordance with the C3 process, the eyes and hands of the designers and modelers are responsible for the final finish, the decisive quantum of emotion. Their craftsmanship is indispensable for Audi in the manufacture design phase.

Manufacture design phase
The permanent comparison between data and clay model helps the handmade manufacture create a more solid foundation. Above and beyond all change steps, the clay model serves as a physical reference, also for the discussion between modelers and designers. Thus it is possible to discuss new design versions in the team at short notice on the digital model and on the physical model and to incorporate changes quickly. Conversely, change requests can be transferred rapidly from the clay model to the CAD model.

Audi’s clay and CAD modelers transform the design confirmed in the C3 process into a handcrafted model in the next stage. The invisible frame of the clay models consists of a steel frame with height-adjustable suspension, wooden panels and a body made out of rigid foam. The overlying layer of industrial plasticine is around 30 to 40 millimeters (1.2–1.6 in) thick. As long as this clay is stored in the laboratory furnace it is as soft as warm butter. It hardens so quickly in the air of the modeling hall that the modeler can work it using various modeling tools. Attachments – from the Singleframe grille, the wheels, to the light module – are created using stereolithography from liquid synthetic resin.

The workflow is designed as an iterative process between CAD modeling and classic clay modeling and perfectly combines the advantages of both worlds. The synthesis of manual modeling and CAD modeling is also embraced when training the employees. Modelers at Audi learn both on the physical model and on the computer, acquiring the skills necessary for CAD tools and manual model making.

Interior and packaging
The interior is a special calling card of Audi Design. The synthesis of design, design language and material in the interior is one of the key reasons for buying for Audi customers worldwide. So the combination of characteristic interior design, fine material selection and innovative operating concepts underscores the quality aspirations of the brand with the four rings.

Inside an Audi the entire design of the interior follows a central design theme. This defining narrative is reiterated throughout the interior – from basic shaping to the design of individual details. This leitmotif extends right through from the dashboard architecture to the individual chrome highlights.

The Audi design process plays a key role in the coherent interior concept. Here, Audi Design boasts a unique selling proposition in the automotive sector: The interior designers accompany the development of the interior from the ideas phase on the drawing board through to series production. This ensures the high quality of the design concept from the key sketch through into production. The interior designers work on a cross-disciplinary and cross-technical team basis throughout the entire development cycle. They liaise in vehicle project teams – say with colleagues from Technical Development, from Quality Assurance or with toolmakers in Production.

After the joint design briefing with the Exterior, Lighting and GUI design teams, three 1:1-scale mock-ups are initially made from foam. On the basis of these forward-structure models with no roof, Design and Technical Development check the proportions, the ergonomics and the package. From the air conditioning, the airbags to the LED light guide, the aim is to house numerous components in the interior. Up to 50 specialist departments are involved in the design process.

At the start of the design phase, seven designers – as competitors and team players at one and the same time – make a start on the key sketches to draw the interior with a couple of lines. Here the clearest ideas make the running: Concepts with an interior made from a single mold, which logically link all the elements in relation to volume and proportion. From the sketches the next stage produces differentiated renderings. Using these, the designers develop the main theme for the individual elements, such as the styling of the door trim.

The design tapes are used in the next work step. These adhesive strips are attached to 1:1 drawings and map the key lines. At the same time the interior is built up in CAD. Once the data model is finished, work begins on milling the clay models. Designers, CAD specialists and modelers jointly develop the final sculpture, from the large volumes to the small details. The harmonious overall image of an Audi interior emerges from the sum of the coherent details, all of which follow a systematically implemented idea. The last 20 percent of the design finish accounts for 80 percent of the work.

Many Audi interior designers are specialists, for example for seats, for all the control elements or for interior lighting. A separate 1:1 model is developed to assess the lighting. Here too, the digitalization of the design process will offer a great deal of potential for transferring design concepts from the draft even faster into series production. As with the exterior design, milestones are used to consolidate and select a final model. The designers agree on the associated packaging in the feasibility check with the final exterior model.

Colleagues from the Feasibility department create a congruence model on the basis of the particular exterior and interior design. They confirm feasibility in relation to production, service, safety and long-term quality. The Design Freeze (DF) for exterior and interior takes place a good two years before the start of production. From this point in time, the design is in the implementation phase and receives its finishing touches in conjunction with the Surfaces department. The latter forms a quasi-bridge between Design and Construction department and is also based in the new Design Center. In the final convergence process, its specialists present all the surfaces in a digital geometric representation accurate down to a hundredth of a millimeter

GUI design
One special area in the Audi interior design is the GUI design (graphical user interface). In the new Audi A7 Sportback and in the new A8, the design of the graphical user interface has become far more important due to the concept of the two MMI touch response displays. This applies to the integration of the screens into the instrument panel and for the operating concept. With the advent of fully digital operating systems, the graphic design of menu levels and operating icons is acquiring an integrated importance between exterior and interior design. First, the graphic design must fit tone-in-tone with the interior’s design language and choice of materials. The menu and icon design must also be configured in such a way that the operating logic and operating reliability are ensured. With ever-increasing complexity, the visualization of vehicle functions such as assistance systems is also becoming increasingly important. In this way, the GUI design also supports the customer’s technology experience.

The Audi GUI designers work together closely with colleagues from Technical Development – both sides develop the basic operating concept in a purpose-built project house. Here they clarify basic questions: How will we structure the menu tree? What function needs to be placed where? What is the right size for an icon so it can be activated reliably and at the same time fits in with the design concept?

The basic layout of the menu structure is developed on the basis of a wireframe wallpaper. This overview representation is similar to a family tree, and the GUI designers define in this representation the entire menu structure of the operating system, from the startup screen down to the last operating level together with the electronics developers.

The Audi designers then design on the computer hundreds of widgets, buttons, labels and screens accurate to a single pixel. All in all they design and program up to 500 individual modules.

The new look of the GUI design is flat, distinctive and, at the same time, with meticulous attention to small details which convey the joy of use. In the main menu, for instance, all icons are subtly animated, the radio wave symbol oscillates slightly. Audi has also gone for a simple design language with a high-quality feel for the graphics design: The clearly arranged ghost design in the MMI displays to the user disparate vehicle functions and convenience features with clear animations. The vehicle animations, say on the menu for Audi drive select, have deliberately been reduced to the key contour lines and illustrate to the customer clearly the selected vehicle functions, for instance when adjusting the seat.

Audi has transferred its exacting quality aspirations from the old world of switches and buttons to the new digital universe. Together with the two-stage tactile feedback – an initial click when touching the user interface, the second tactile feedback when executing the operating command – high-quality, simply designed operating icons generate the brand’s familiar high quality aspirations.

Colors and materials
Once the first foam models of the exterior and interior have been put together, the designers from Color and Trim embark on a new project and start work on the color and materials concepts. What degree of sheen best suits which equipment line for the bars of the Singleframe? Do the decorative trim, trim strips and leather upholstery create an overall harmonious feel? Is there a harmonious overall image in areas such as the door where many elements come together?

Color and Trim also produce 1:1 models for larger components such as instrument panel, center console and seats. Particularly with the seats this involves seam details, pattern and perforation as well as the color schemes. The new Audi high-end visualization tools also make it easier to put together these elements. The most important tools remain, however, the highly sensitive fingertips and an eye that can appreciate the smallest color nuances in terms of sheen and depth. It takes years to train these skills fully.

The Color and Trim models run through the usual Audi Design project gates and milestones. The final definition emerges around two years before the start of production. It constitutes the starting point for the intense collaboration with Quality Assurance and the suppliers. The latter are retrained with each project so that the interiors always meet Audi’s exacting demands in terms of precision and quality.

Virtual reality
In the Audi design process the high-end visualization on the LED wall is the present; virtual reality (VR) is the next step. The method developers in the Design department develop specialist tools and methods for using VR glasses, so-called head-mounted displays (HMDs), which fully transport the observer visually into the depicted setting. The interior designers in particular can use the technology right from the concept phase to experience proportions and spatial concepts, and assess these reliably. With the commissioning of the new Design Center these HMDs visualize spatial concepts and proportions in the interior design. To this end, the VR developers have their own VR lab where the team coordinates the new tools together with the designers.

The design places exacting demands on the representation quality. Do the reflections, the reflections in the paintwork, the shadow of the VR coincide with the reality? The computer cluster also provides this quality in the VR glasses. It delivers rapidly precalculated, high-resolution image content, which is then displayed in three dimensions by powerful HMDs. This also enables the user to move around the virtual space and point at objects. The lifelike representation of design models is thus even more realistic. Over the next three to five years, VR applications will become the standard tool in the design process. Virtual-reality tools will augment today’s digital design manufacture with other virtual applications.

The further steps are already emerging: Tools that enable the observer to add markers in the simulation, and differentiated tools to virtually touch and move individual elements. Augmented reality places the computer-generated representations over the real world and paves the way for the new approach of eye scanning: Only those objects the user focuses on are displayed sharply, everything else is blurred, reflecting the way the eye behaves naturally.

In the foreseeable future, VR glasses will also facilitate design meetings across continents and substantially support the design process even further. Then Audi designers, for instance, from Ingolstadt, Beijing and Los Angeles will get together in a virtual studio to discuss and assess a digital model. This eliminates cumbersome model transport or travel time. Each participant sees in real time the same virtual model and also perceives the other discussion participants as avatars. Avatars are assigned to the individual participants in the VR meeting as individual virtual representatives.

Data gloves are also in the pipeline and will permit “digital touching” of virtual models using tactile feedback. VR meetings will replace video conferences and offer entirely new opportunities.

The equipment, data and prices specified in this document refer to the model range offered in Germany. Subject to change without notice; errors and omissions excepted. Standaufnahme,