| name | gmsh-meshing-common-issues |
| description | Sub-skill of gmsh-meshing: Common Issues (+1). |
| version | 1.0.0 |
| category | engineering |
| type | reference |
| scripts_exempt | true |
Common Issues (+1)
Common Issues
| Problem | Cause | Solution |
|---|
| Empty mesh output | Missing synchronize() | Call gmsh.model.geo.synchronize() or gmsh.model.occ.synchronize() before meshing |
| Wrong element types | Default is triangles | Use setRecombine() for quads, or RecombineAll option |
| Poor quality at corners | Sharp angles | Add local refinement or increase Mesh.Smoothing |
| STEP import fails | Topology issues | Enable Geometry.OCCFixDegenerated, OCCFixSmallEdges, OCCSewFaces |
| MSH format not recognized | Wrong version | Set Mesh.MshFileVersion to 2.2 for BEM tools |
| Physical groups empty | Not assigned | Must define physical groups before write() |
| Transfinite fails | Incompatible topology | Surface must be 3 or 4-sided, curves must have matching node counts |
| Size fields ignored | Other size sources active | Disable MeshSizeExtendFromBoundary, MeshSizeFromPoints, MeshSizeFromCurvature |
| Crash on large models | Memory | Use -nt for parallel meshing, increase verbosity to find bottleneck |
gmsh CLI: /usr/bin/env: 'python': No such file or directory | pip-installed gmsh wrapper uses #!/usr/bin/env python shebang | Fix shebang: sed -i 's|python$|python3|' ~/.local/bin/gmsh; or use /usr/bin/gmsh (system binary) |
| pip gmsh shadows system gmsh | ~/.local/bin/gmsh (pip wrapper) takes precedence over /usr/bin/gmsh (native) | Check type -a gmsh; pip version is Python-only (no GUI), system version has FLTK GUI |
Debugging Tips
gmsh.option.setNumber("General.Verbosity", 99)
print(gmsh.model.getEntities())
print(gmsh.model.getEntities(dim=2))
xmin, ymin, zmin, xmax, ymax, zmax = gmsh.model.getBoundingBox(-1, -1)
gmsh.fltk.run()
gmsh.model.mesh.generate(2)
node_tags, _, _ = gmsh.model.mesh.getNodes()
print(f"Number of nodes: {len(node_tags)}")
elem_types, elem_tags, _ = gmsh.model.mesh.getElements(dim=2)
total_elems = sum(len(t) for t in elem_tags)
print(f"Number of elements: {total_elems}")
