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is an open access repository that collects the work of Arts et Métiers ParisTech researchers and makes it freely available over the web where possible. AbstractThe presence of holes in a triangle mesh is classically ascribed to the deficiencies of the point cloud acquired from a physical object to be reverse engineered. This lack of information results from both the scanning process and the object complexity. The consequences are simply not acceptable in many application domains (e.g. visualisation, finite element analysis or STL prototyping). This paper addresses the way these holes can be filled in while minimizing the curvature variation between the surrounding and inserted meshes. The curvature variation is simulated by the variation between external forces applied to the nodes of a linear mechanical model coupled to the meshes. The functional to be minimized is quadratic and a set of geometric constraints can be added to further shape the inserted mesh. In addition, a complete cleaning toolbox is proposed to remove degenerated and badly oriented triangles resulting from the scanning process.

International audienceThe use of free-form shapes has become mainstream to design complex products that have to fulfil engineering requirements as well as aesthetic criteria. Even if today’s CAD systems can easily represent free-form shapes by means of NURBS surfaces, their definition and modification still require a deep knowledge and a great skill in the manipulation of the underlying mathematical models. The implemented free-form shapes design operators are time consuming and do not enable fast modifications. To overcome these limits, some researches have been undertaken to try to adapt the feature concept, successfully adopted for the design of regular shapes, in the free-form domain. It gives rise to a set of free-form features modelling strategies. This paper gathers together the state-of-the-art of these advances. The various approaches are depicted and compared with respect to a very precise set of criteria expressing the needs in aesthetic and engineering designs. The limits and future trends are presente

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