XelToFabCLI Reference
xtf extrude
Extrude a 2D scalar field into a 3D triangle mesh
Usage
xtf extrude [OPTIONS] INPUT_PATHLoad a 2D scalar field, build a watertight prism by marching-squares contour tracing and polygon triangulation, and write the result to an STL, OBJ, or PLY file.
Arguments
| Argument | Description |
|---|---|
INPUT_PATH | Path to the input 2D scalar field file (must exist). Must resolve to a 2D array. |
Options
| Option | Type | Default | Description |
|---|---|---|---|
-o, --output | PATH | (required) | Output mesh file path. Format determined by extension (.stl, .obj, .ply). |
-t, --thickness | FLOAT | (required) | Extrusion height in grid units. Must be > 0. |
-f, --field-name | TEXT | None | Variable name inside container formats (.npz, .mat, .h5, .vtk). |
--shape | TEXT | None | Grid shape for flat data, e.g. 25x50 (for CSV/TXT). |
--field-type | density|sdf | density | Input field type. sdf flips the threshold direction and shifts the default --level to 0.0. |
--level | FLOAT | (auto) | Iso-level override. Default: 0.5 for density, 0.0 for SDF. |
--min-component-area | INT | 0 | Drop connected components smaller than N pixels. |
--smooth-sigma | FLOAT | 0.0 | Pre-threshold Gaussian sigma. 0 disables. |
--fill-holes | flag | False | Morphologically close single-pixel pinholes before tracing. |
Examples
Basic density → STL
xtf extrude density_2d.npy -o part.stl --thickness 10SDF input
xtf extrude sdf_field.npy -o part.stl -t 10 --field-type sdfThe --level default becomes 0.0 automatically under --field-type sdf.
Printability cleanup
xtf extrude beam.npy -o beam.stl -t 15 \
--smooth-sigma 0.8 \
--fill-holes \
--min-component-area 20Smooths noise, closes pinholes, and drops disconnected specks smaller than 20 pixels.
MATLAB input with named variable
xtf extrude result.mat -o mesh.stl -t 5 -f xPhysIf -f is omitted, the loader auto-detects common topology-optimization variable names (xPhys, densities, x, rho, dc, density).
Flat CSV with explicit shape
xtf extrude field_25x50.csv -o mesh.stl -t 8 --shape 25x50Custom iso-level
xtf extrude density.npy -o mesh.stl -t 10 --level 0.4Lowering the level includes more material in the binarized mask — useful when the optimizer output has gray regions you want to retain.