RE-ENGINEERING EXTERIOR DESIGN - GENERATION OF CARS BY MEANS OF A FORMAL GRAPH-BASED ENGINEERING DESIGN LANGUAGE

Sep 29, 2026

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Car exterior design is treated as a creative, largely human-executed task, and the paper analyzes the human-assisted process using a case study from the Audi car family. It defines a formal, graph-based engineering design language with explicit syntax, semantics, and pragmatics for Class A surface quality. The approach reconstructs the Audi family’s exterior design and re-engineers an Audi A3 Sportsback, translating a design graph into CATIA V5 3D-CAD models for isophotic surface quality checks.

LanguageEnglish

CategoryResearch & Report

FormatPDF

Pages12

Reading Time30 min

AccessFree to download

Abstract

1 Introduction

2 Review of the Styling Process

Method overview

Motivation and research questions

INTERNATIONAL CONFERENCE ON ENGINEERING DESIGN, ICED’07 28-31 AUGUST 2007 , CITÉ DES SCIENCES ET DE L' INDUSTRIE, PARIS, FRANCE RE-ENGINEERING EXTERIOR DESIGN: GENERATION OF CARS BY MEANS OF A FORMAL GRAPH-BASED ENGINEERING DESIGN LANGUAGE Stefan Pfitzer1, Stephan Rudolph2 1 ,2 Institute for Statics and Dynamics of Aerospace Structures, University of Stuttgart ABSTRACT The exterior design of cars is considered to be a highly creative task typically executed by experienced human designers. Based on a case study of the Audi car family, both a careful analysis of the humanassisted exterior design process has been assessed, as well as the syntax, semantics and pragmatics of a formal, graph-based engineering design language for the exterior design of cars with class A surface quality has been created. The design language allows for the almost complete reconstruction of the exterior design of the Audi car family (only smaller details such as side and rear mirrors, door seals, etc. have been omitted) and is demonstrated in this study to be able to re-engineer the exterior of an Audi A3 Sportsback. The syntax of this styling language consists of so-called characteristic lines and elements (“design genes”, according to consistently used company terminology) and is used to create a graphical representation of an Audi specific design graph. The design graph is automatically translated into a 3D-CAD model using CATIA V5 as the geometry engine and is finally subject to a visual surface quality check using the isophotic analysis menu in CATIA V5. Keywords: Exterior design, automated surface reconstruction, characteristic lines, characteristic elements, design graph, design rules, design language, design compiler 1 INTRODUCTION With the change of the automobile from a luxury to a commonly used lifestyle product, the importance of its exterior design as a means to express individual customers preferences and social standing has considerably increased. It is therefore not surprising that the time spent in styling a new automobile in order to optimally address a certain target group is nowadays considered as one of the most important parts in the design decision making process. While the technical and technological parts of the product creation process are investigated in a variety of other research activities to accelerate and/or optimize parts of the design process by specialized software tools, the actual exterior design process still lacks such support greatly and is until today characterized by repetitive manual tasks executed by human designers. However, designers do have a number of “design rules” in mind (i.e. the corporate identity style guide and package concept requirements) when styling a car. It is therefore one of the central scientific questions raised and investigated in this work as to what an extent such styling rules, which may obviously be hard to grasp in a technical sense, can be expressed and incorporated in a formal graph-based design language. Since designers have to keep in mind restrictions concerning packaging and law regulations affecting the exterior of the automobile however, it seems obvious that at least these aspects may be formally expressed as rules in such a design language. Design languages, also known as design grammars, have already been successfully applied to a variety of related design and styling tasks. In [1] a shape grammar has been developed together with expert designers to draw the characteristic lines of the front, side and rear views of future cars, allowing by a careful intermixing of the conceived rules the creation of so-called “cross-over products”. Further design examples of applications of all kinds of string-based, shape-based and graph-based design languages can be found in a very up-to-date literature overview [2] . The effectiveness and efficiency of rule-based mechanisms has been demonstrated in [3], where a rule-based mechanism is iteratively used for the generat

FAQs

What is the main goal of the study on car exterior design?

To formalize exterior styling knowledge into a graph-based engineering design language that can reconstruct and re-engineer car exteriors with class A surface quality.

How does the proposed design language represent exterior styling?

Its syntax uses characteristic lines and characteristic elements (design genes) to build an Audi-specific graphical design graph.

How is the design graph turned into a 3D model and validated?

The design graph is automatically translated into a 3D-CAD model using CATIA V5, followed by a visual surface quality check via the isophotic analysis menu in CATIA V5.

Sep 29, 2026

Upload by Rowan