1. A method for designing a modeled object having several faces, the method being implemented with a computer system comprising at least one computer processor, said method comprising the steps of: identifying, using said at least one computer processor, for each of said faces, at least another of said faces related to said face according to geometrical criteria; computing, using said at least one computer processor, a plurality of points forming a tessellated representation of each of said faces; wherein for each of said faces; for each point of the tessellated representation of said face; determining, using said at least one computer processor, and storing data representative of an intersection between a three-dimensional geometrical figure extrinsic to said modeled object and touching said point and another face identified as a face related to said face; computing, using said at least one computer processor, frontiers between points according to their respectively stored data; determining, using said at least one computer processor, zones according to the computed frontiers; and computing, using said at least one computer processor, new faces according to the determined zones.