Hierarchical generation of unstructured meshes over free-form polyhedra
Résumé
For a few years, polyhedral models have been used to model the geometry of an object in reverse engineering applications and visualisation processes. The development of methods to adapt accurate polyhedra requires treatments in order to manipulate these models and to adjust polyhedra for the purpose of its future uses. The aim of this paper is to present a new approach devoted to the generation of polyhedra based on an initial polyhedral geometry. This method uses as input an arbitrary polyhedron which is subdivided into several parts with respect to its geometric features. The determination of the main features of the object is carried out thanks to a polyhedron simplification method which preserves the geometry of the initial model. Then, a mapping between the initial and the simplified polyhedra leads to the determination of several partitions used in a parametrization of the surface of the model. Afterwards, the simplification method is used to generate a first polyhedron to initiate the remeshing process. This method guarantees the conformity of this representation. Moreover, a significant number of applications are based on polyhedra, and require the generation and the adaption of a lot of models for their future uses. To this end, this new approach of remeshing is incorporated into a hierarchical data structure.