Compile an OpenSCAD source file

pyvista_cad.read_scad shells out to the openscad CLI, captures the STL it emits, and returns it as a pyvista.PolyData. The OpenSCAD binary must be installed and on PATH.

This example compiles a real OpenSCAD library, threads.scad by Ryan A. Colyer (CC0, rcolyer/threads-scad), a widely used parametric ISO metric fastener generator. Its top-level Demo() renders real bolts, nuts, and washers.

import pyvista as pv

import pyvista_cad
from pyvista_cad.examples import downloads

Compile the real .scad source. The openscad binary must be installed and on PATH. threads.scad exposes a top-level screw_resolution (mm); the default 0.2 tessellates the helices very finely and is slow. -D screw_resolution=0.6 is ~3x faster and the thread features still read clearly: ample for a gallery render. The fast manifold backend is applied automatically (OpenSCAD >= 2024) with a fallback to CGAL.

mesh = pyvista_cad.read_scad(
    downloads.scad_threads_path(),
    args=('-D', 'screw_resolution=0.6'),
)
mesh

PolyData (0x7f6fa81d5180)
  N Cells:    43072
  N Points:   21556
  N Strips:   0
  X Bounds:   -7.306e+00, 8.000e+01
  Y Bounds:   -8.920e+01, 5.900e+01
  Z Bounds:   0.000e+00, 4.000e+01
  N Arrays:   3

PolyData 21,556 points 43,072 cells 1.6 MiB

Bounds⧉X [-7.306e+00, 8.000e+01]Y [-8.920e+01, 5.900e+01]Z [0.000e+00, 4.000e+01]

Cellsfaces 43,072

• Field Data: (3)
  • cad.source_format⧉
    (1,)
    <U4
  • cad.backend⧉
    (1,)
    <U8
  • cad.label⧉
    (1,)
    <U12

Render colored by Z so the fastener features read.

mesh['elevation'] = mesh.points[:, 2]

pl = pv.Plotter()
pl.cad.add(mesh, scalars='elevation', cmap='viridis')
pl.show()

Static Scene

Interactive Scene