Abstract: A computer-implemented method for designing a 3D modeled object. The 3D modeled object represents a mechanical part formed in a material having an anisotropic behavior with respect to a physical property. The method includes obtaining a 3D finite element mesh and data associated to the 3D finite element mesh. The data associated to the 3D finite element mesh includes a plurality of forces and boundary conditions. The plurality of forces forms multiple load cases. The method further comprises optimizing an orientation field distributed on the 3D finite element mesh with respect to an objective function. The objective function rewards orientation continuity with respect to the physical property. The optimizing is based on the 3D finite element mesh and on the data associated to the 3D finite element mesh. This constitutes an improved method for designing a 3D modeled object.