1.5 What Gmsh is pretty good at …

Gmsh is a (relatively) small program, and was principally developed “in academia, to solve academic problems”… Nevertheless, over the years, many people outside universities have found Gmsh useful in their day-to-day jobs. Here is a tentative list of what Gmsh does best:

• quickly describe simple and/or “repetitive” geometries, thanks to user-defined functions, loops, conditionals and includes (see User-defined functions, Loops and conditionals, and General commands);
• parameterize these geometries. Gmsh's scripting language enables all commands and command arguments to depend on previous calculations (see Expressions, and Geometry commands);
• import complex models in industry-standard formats like STEP or IGES (when Gmsh is built with OpenCascade support);
• generate 1D, 2D and 3D simplicial (i.e., using line segments, triangles and tetrahedra) finite element meshes. The performance of the 1D and 2D algorithms is pretty good; the 3D algorithm is still experimental and slow (see Mesh module, and Tutorial);
• specify target element sizes accurately. Gmsh provides several mechanisms to control the size of the elements in the final mesh: through interpolation from sizes specified at geometry points or using flexible mesh size fields (see section Mesh commands);
• create simple extruded geometries and meshes (see Geometry commands, and Mesh commands);
• interact with external solvers. Gmsh provides C, C++, Perl and Python interfaces, and others can be easily added (see section Solver module);
• visualize computational results in a great variety of ways. Gmsh can display scalar, vector and tensor data sets, and can perform various operations on the resulting post-processing views (see section Post-processing module);
• export plots in many different formats: vector PostScript or encapsulated PostScript, LaTeX, PNG, JPEG, … (see section General options);
• generate complex animations (see General tools, and ‘t8.geo’);
• run on low end machines and/or machines with no graphical interface. Gmsh can be compiled with or without the GUI, and all versions can be used either interactively or directly from the command line (see section Running Gmsh);
• configure your preferred options. Gmsh has a large number of configuration options that can be set interactively using the GUI, scattered inside command files, changed on the fly in scripts, set in per-user configuration files, or specified on the command-line (see General options, Geometry options, Mesh options, Post-processing options, and Running Gmsh);
• and do all the above on various platforms (Windows, Mac and Unix), for free (see section Copying conditions), using clear-text ASCII files and/or a small but powerful graphical user interface.