Feature based volumes for implicit intersections.

The automatic generation of volumes bounding the intersection of two implicit surfaces (isosurfaces of real functions of 3D point coordinates) or feature based volumes (FBV) is presented. Such FBVs are defined by constructive operations, function normalization and offsetting. By applying various offset operations to the intersection of two surfaces, we can obtain variations in the shape of an FBV. The resulting volume can be used as a boundary for blending operations applied to two corresponding volumes, and also for visualization of feature curves and modeling of surface based structures including microstructures

The building information modeling for the retrofitting of existing buildings. A case study in the University of Cagliari.

Italy's very consistent buildings stock has become the major field for real estate investments and for the related projects and actions. The urge of working on built environment is however facing some crucial issues. The first is the lack of documentation on the construction history and on the real constructive layout of existing buildings (in terms of components, installations, plants, etc.). The second is the poor activity in surveying their current status, with reference to use (energy behaviour, real consumptions, etc.) and maintenance (conservation status, previous maintenance works, compliance with current regulations, etc.). These obstacles cause a deep inefficiency in the planning, programming and controlling of requalification and/or refunctionalisation works. Starting from these assumptions, this paper shows the findings of a research shared by the Politecnico of Milan and the Department of Civil and Environmental Engineering and Architecture of the University of Cagliari. It is aimed at testing the use of building information modeling (BIM) to structure the necessary knowledge to evaluate intervention scenarios. The research is focused on the Mandolesi Pavilion of the University of Cagliari, designed by Enrico Mandolesi. It is a highly stimulating architectural object because it incorporates values that require a conservative approach, but at the same time, like most contemporary buildings, it was designed and built for innovation and not for “long duration”. The work has actually led to the realization of a BIM model of the case study. It represents the first prefiguration of an approach that develops from construction history and continues with advanced diagnostics on the statical and energy performances of the building. The model formalizes knowledge and information on a significant building, aimed at its management. It allows also the setting of intervention scenarios that can be evaluated with real-time simulations of cost, time and ROI

Geometric Modeling of Cellular Materials for Additive Manufacturing in Biomedical Field: A Review

Advances in additive manufacturing technologies facilitate the fabrication of cellular materials that have tailored functional characteristics. The application of solid freeform fabrication techniques is especially exploited in designing scaffolds for tissue engineering. In this review, firstly, a classification of cellular materials from a geometric point of view is proposed; then, the main approaches on geometric modeling of cellular materials are discussed. Finally, an investigation on porous scaffolds fabricated by additive manufacturing technologies is pointed out. Perspectives in geometric modeling of scaffolds for tissue engineering are also proposed