Methods for the Evaluation and Deformation of Curves Based on Aesthetic Criteria

The work of this thesis was aimed at extending the semantic-oriented modeling tools for the creation and deformation of free form digital shapes developed in the collaboration between the Institute IMATI of the Italian National Council of Research in Genoa and the Laboratory LSIS - Ecole Nationale Superieure d'Arts et Metiers of Aix-en-Provence. These semantic- oriented modeling tools result from the knowledge acquired from the active participation of the involved researchers in two projects supported by the European Commission: FIORES-II and AIM@SHAPE. The Research and Development project FIORES-II (Character Preservation and Modeling in Aesthetic and Engineering Design), directly and actively involved, beside several research institutions, important companies in the eld of industrial design, such as Alessi, BMW, Pininfarina, Saab, Formtech and Eiger. The increasingly attention to the aesthetic aspect in the present com- petitive worldwide market requires more appropriate tools for the industrial design process. To this purpose the FIORES-II project aimed at the iden- ti cation and development of new intent-driven modeling tools for direct shape modi cation. It proposed an innovative approach in computer-aided industrial design, in order to support the creative stylist mentality in more easily attaining a model with a certain aesthetic and emotional character, and in its preservation during the model modi cations. A more general approach to create semantic-oriented 3D models has been studied by the Network of Excellence AIM@SHAPE (Advanced and Inno- vative Models And Tools for the development of Semantic-based systems for Handling, Acquiring, and Processing knowledge Embedded in multidi- mensional digital objects), coordinated by IMATI - CNR and involving key leader European institutions in the eld of computer graphics and se- mantic technologies, such as Max-Plank, Fraunhofer, Sintef and MIRALab of Geneve University. The approach, applicable to geometric digital mod- els both directly created with computer-aided tools (as in design activities) or reconstructed from real ones (as the case of scanned models), considers three layers of representation and knowledge which allow an easier coding and mapping between application contexts. The three levels include: geom- etry to represent the object shape; structure to organize and abstract the geometric description to make easy the association of semantic data that are speci c of the considered application and re ect the needs of the related experts working on the digital models. As this thesis adopt the semantic-oriented modeling approach, the work in- tegrate the directives suggested by the FIORES-II project results, regarding the shapes evaluators and operators pointed out in its research, with the re- sults of works carried out in AIM@SHAPE related to the shape modi cation, implementing and extending a Matlab toolbox developed by Jean-Philippe Pernot and extended in. The thesis is organized as it follows:
Chapter 1 illustrates brie y the main aspects related to the industrial design process and work ow; then the adopted geometric description for surfaces and curves is given, showing also which methods can be utilized for the evaluation of the quality of the geometric elements, during the creation and modi cation phases of the design process.
Chapter 2 describes the basic elements for the de nition of semantic-based design. Free form features are illustrated together with their aesthetic prop- erties, commonly considered by stylists. Finally the adopted multilevel- based shape organization is shown, followed by the Leyton's grammar de- scription for the curve classi cation at the structural level.
Chapter 3 explains in details the meaning and the mathematical represen- tation of the aesthetic properties de ned in FIORES-II, with some relative measure implementations and evaluations.
Finally, chapter 4 is entirely dedicated to the description of the implemented shape modi er focusing on the aesthetic property of the straightness. The results obtained are shown, setting the basic elements for possible future Works.