Читать книгу IGA - Robin Bouclier - Страница 27

Although based on the same basis functions, the link between CAD and analysis, originally advocated by IGA, is not trivial in practice. Indeed, standard IGA requires a boundary-fitted discretization for the analysis, while in CAD programs, where the only matter is the rendering of the geometry, entities are described as a collection of their boundary surfaces that can be joined and/or intersected through Boolean operations. When the artificial parts of the surfaces are cut away, the visualization of the resulting object changes, while its mathematical description does not. To clarify this point, we need to introduce the concept of trimming and the related issue of non-conforming multipatch analysis. These two challenges are currently the object of intensive studies from both the geometric modeling and scientific computing communities, since they are primordial to truly bridge the gap between CAD and analysis.