stepfg: STEP File Generator

Python 3.8+ | Zero dependencies | MIT License

Authors: E. Valetov and M. Berz Organization: Michigan State University Creation date: 03-Feb-2017

Introduction

stepfg converts lists of 2D polygons (specified by vertices in the x-y plane) into 3D STEP files (ISO 10303-242) by extruding the polygon interiors along the z-axis. Pure Python, no external dependencies.

Installation

pip install stepfg

Or from source:

git clone https://github.com/evvaletov/stepfg.git
cd stepfg
pip install -e .

Library usage

from stepfg import StepBuilder, generate_step

# Quick one-liner
content = generate_step(
    polygons=[[[0, 0], [1, 0], [1, 1], [0, 1]]],
    z_range=[0, 10],
    scale=1,
)

# Or use StepBuilder for more control
builder = StepBuilder('output.stp')
builder.generate_assembly(
    list_vert_list=[[[0, 0], [1, 0], [1, 1], [0, 1]]],
    geom_depth_list=[0, 10],
    p_coeff=1,
)
builder.to_file('output.stp')

Command-line usage

stepfg [input_file [output_file]]
python -m stepfg [input_file [output_file]]

Run with the included sample geometry (a Muon g-2 quadrupole):

stepfg part_geometry.txt quadrupole.stp

Input file format

Both Python literal and JSON formats are supported.

Python literal (original format)

[polygons, z_range, scale]

See part_geometry.txt for a full example (Muon g-2 quadrupole).

JSON (object or array)

{
  "polygons": [[[0, 0], [4, 0], [4, 4], [0, 4]]],
  "z_range": [0, 10],
  "scale": 1
}

The scale key is optional (defaults to 1). A JSON array [polygons, z_range, scale] is also accepted. See part_geometry.json for a full example.

Fields

• polygons: [[vertex, ...], ...] — each vertex is [x, y] or [x, y, 0]
• z_range: [z1, z2] — extrusion interval
• scale: proportionality coefficient (output is in mm; use 10 for cm input)

Copyright Notice

© 2017 Eremey Valetov and Martin Berz