The shells are structures which resist mainly by the inherent properties of its forms when they are requested by several actions, enabling constructions extremely slender and different architecture. The property of resistance is even more evident when the shapes of the shells are optimized to obtain the structural behavior in membrane regime with bending stresses no or negligible However, design of free-form shells are complex due to the computational difficulties of its generation, since the three-dimensional structures with shapes optimized of shell cannot be represented by mathematical equations. This paper aims to present a computational approach to facilitate the generation of optimized shapes of shells through the development of a software generator of membranes with different polygonal plants. After the initial modeling of a flat mesh formed by triangular elements and automatically generated, the computational generation of the three-dimensional shapes is performed by means of Finite Element Method considering the membranes subjected to large displacements and large deformations. The software for meshing initial plan through a standard set was developed in C programming language, with capacity to generate information relating to Finite Element Method such as the coordinates and nodal incidence of triangular elements with six degrees of freedom per node. The structures in shell generated through flexible membranes are polygonal projection with a minimum of three sides, and its boundary conditions are the regions of the vertices that remain fixed after the application of the loadings. The various models of optimized shapes depend of the numbers of fixed supports, and are obtained by varying the intensity of the load actions on the membrane. Several models of shapes obtained are presented to corroborate the results obtained.