1. A method of computer-aided design of a 3D object modeled by: (i) cells, the cells being restrictions of geometries of a model of the 3D object, and (ii) a cell graph comprising relations between the cells, which relations capture a topology of the model, the method comprising the steps of: editing an initial model by interacting with a user to identify intended displacements of initial geometries of the model, and selecting the cells which are restrictions of the geometries to be displaced; collecting cells adjacent to the selected cells according to the cell graph, some of the adjacent cells being excluded by predefined rules; computing by a solver, transformations to be applied to initial geometries, from the intended displacements and geometries whose collected cells are restrictions thereof, and building new geometries according to said transformations and initial geometries.