Automatic boundary detection
Hi, I wonder if GMSH has any tools for automatically detecting the boundaries/surfaces of mesh. Like for instance, I have a complex biological geometry, all i can generate is a 3D mesh in GMSH. But when importing to CFD software, I would like boundaries to be tagged such that I can apply my boundary conditions.
[In AutoCAD] I found one algorithm as such, the algorithm iterates all facets, and measures its angle made with its neighbour facets. If the angle is less than threshold, it marks with certain ID. This way they create face groups which are boundaries. I know, this is fully dependent on the way we tune the parameters (eg. threshold angle, number of groups), but it helps a lot. This is only for STL files, i would like to see if there is any for 3D meshes in GMSH.
Thanks.