edd4e73Mesh converter: upload, view, and export meshes across formatsJeremy Magland 1# mesh-converter
3A static web app for converting meshes between formats: upload a mesh file,
50876cdConvert real mesh formats with meshio via PyodideJeremy Magland 4inspect it in an interactive 3D view (shaded, wireframe, shaded + wireframe,
5or points), and download it in a format of your choice. Formats differ in what they can store, and the UI shows exactly which
6attributes (normals, colors) would be dropped by a lossy conversion.
50876cdConvert real mesh formats with meshio via PyodideJeremy Magland 8Conversion is powered by [meshio](https://github.com/nschloe/meshio) running
9in the browser via [Pyodide](https://pyodide.org) — no server, all mesh I/O
10happens client-side. The first visit downloads the Python runtime (~15 MB from
11the jsDelivr CDN, cached afterwards).
50876cdConvert real mesh formats with meshio via PyodideJeremy Magland 13| Format | Extension | positions/faces | normals | colors | notes |
edd4e73Mesh converter: upload, view, and export meshes across formatsJeremy Magland 14| --- | --- | --- | --- | --- | --- |
50876cdConvert real mesh formats with meshio via PyodideJeremy Magland 15| PLY (Polygon File Format) | `.ply` | ✓ | ✓ | ✓ | |
16| Wavefront OBJ | `.obj` | ✓ | ✓ | — | |
17| STL | `.stl` | ✓ | — | — | binary |
18| OFF (Object File Format) | `.off` | ✓ | — | — | |
19| VTK legacy | `.vtk` | ✓ | ✓ | ✓ | |
20| VTU (VTK XML) | `.vtu` | ✓ | ✓ | ✓ | |
21| Gmsh MSH | `.msh` | ✓ | — | — | |
22| XDMF | `.xdmf` | ✓ | ✓ | ✓ | h5py† |
23| MED (Salome) | `.med` | ✓ | ✓ | ✓ | h5py† |
24| H5M (MOAB) | `.h5m` | ✓ | ✓ | ✓ | h5py† |
25| AVS-UCD | `.avs` | ✓ | ✓ | ✓ | |
26| Abaqus | `.inp` | ✓ | — | — | |
27| Nastran | `.bdf` | ✓ | — | — | |
28| Medit | `.mesh` | ✓ | — | — | |
29| Netgen | `.vol` | ✓ | — | — | |
30| MDPA (Kratos) | `.mdpa` | ✓ | — | — | |
31| Tecplot | `.dat` | ✓ | — | — | |
32| DOLFIN XML | `.xml` | ✓ | — | — | |
33| PERMAS | `.post` | ✓ | — | — | |
35† HDF5-based formats need the h5py Pyodide package (~4 MB); it is loaded
36lazily the first time such a format is used, so the default footprint stays
37small.
39✓ marks what this app preserves when writing the format: vertex normals map to
40each format's native representation (`nx/ny/nz` properties in PLY, `vn` lines
41in OBJ, a `Normals` point-data array elsewhere) and vertex colors likewise
42(`red/green/blue` in PLY, an `RGB` point-data array elsewhere). On import,
43quads and polygons are fan-triangulated; volume cells are skipped.
45Some meshio formats are deliberately absent: ansys, cgns, su2, and ugrid
46cannot roundtrip their own output in meshio 5.3.5; exodus fails writing under
47wasm; flac3d holds volume cells only; wkt's reader hangs on non-toy meshes;
48tetgen spans two files; svg is write-only.
50A built-in sample mesh (a rainbow torus with normals and vertex colors) is
50876cdConvert real mesh formats with meshio via PyodideJeremy Magland 51available from the UI for trying things out without a file, and `examples/`
52holds it pre-exported in a few formats. An on-demand "estimate export sizes"
53action serializes the loaded mesh to every format in memory and shows the
54resulting file sizes in the format table and export dropdown.
56## Development
58```bash
59npm install
60npm run dev # local dev server
61npm run build # static build in dist/
62```
64Built with Vite, React, TypeScript, and three.js (react-three-fiber).
50876cdConvert real mesh formats with meshio via PyodideJeremy Magland 68- `src/mesh/bridge.py` runs inside Pyodide: it reads/writes mesh files with
69 meshio and exchanges arrays with JS as raw little-endian buffers through
70 Pyodide's in-memory filesystem.
71- `src/mesh/meshio.ts` loads Pyodide (script tag in `index.html`), installs
72 meshio via micropip, and wraps the bridge in typed async
73 `parseMeshFile`/`serializeMesh` functions built on the internal `MeshData`
74 representation (typed arrays of positions, triangle indices, optional
75 normals/colors).
76- `src/mesh/formats.ts` declares the supported formats and which attributes
77 each preserves; the upload, capability table, and loss-warning UI derive
78 from it. To add a meshio-supported format, add a descriptor there (with
79 `pyodidePackages` if it needs extra prebuilt packages such as h5py) and, if
80 it stores normals/colors in a format-specific way, teach
81 `bridge.py` how to map them.