Lourenço, DanielOliveira, PedroBidarra, RafaelLopes, Adriano2021-10-112021-10-112021978-3-03868-164-9https://doi.org/10.2312/pt.20051459https://diglib.eg.org:443/handle/10.2312/pt20051459In feature based systems support for direct manipulation is not commonly available. This is partly due to the strong reliance of feature modelling systems on constraints and on the lack of speed of current constraint solv­ ers. In this paper an approach to the optimization of the geometric constraint solving for the specific situation of direct manipulation is described. Also a solution for a direct manipulation interface was designed that brings to feature modelling the advantages of direct manipulation while taking into account the main feature model­ ling paradigm concepts. Details are provided on how it was implemented successfully in the SPIFF feature mod­elling system.Feature­modellingDirect manipulationCAD/CAM10.2312/pt.20051459167-171