Export and import

Export evaluates geometry and writes a file; neither show() nor the graphical interface is needed.

STL, STEP and 3MF

import zencad as z

part = z.box(20) - z.cylinder(4, 20).translate(10, 10, 0)
z.export_stl(part, "part.stl", binary=True)
z.export_step(part, "part.step", unit="mm")
z.export_3mf(part, "part.3mf", unit="mm", name="Bracket")

Exporters interpret source coordinates as millimetres. unit selects the file units: mm, cm, m, um, in, ft or their full names. For example, with unit="cm", a dimension of 20 is written as 2 centimetres. STL stores no unit metadata: only the coordinate scale changes.

linear_tolerance and angular_tolerance control STL/3MF mesh detail. Linear tolerance uses the file units; a smaller tolerance produces a finer mesh. STEP does not require triangulation.

A binary stream can be passed instead of a path:

import io
import zencad as z

stream = io.BytesIO()
z.export_step(z.box(10), stream)
assert stream.getvalue().startswith(b"ISO-10303-21")

Invalid shapes raise ShapeValidationError; write failures raise OSError. to_stl(model, path, delta) is a shorthand for ASCII STL export; delta controls mesh detail, and success returns True.

BREP

import zencad as z

z.to_brep(z.box(3), "part.brep")
restored = z.from_brep("part.brep")
restored.assert_valid()

SVG

For files, use to_svg(model, path) and from_svg(path). For strings, use to_svg_string(model) and from_svg_string(svg).

import zencad as z

svg = z.to_svg_string(z.rectangle(20, 10))
restored = z.from_svg_string(svg)
restored.assert_valid()

SVG works with planar geometry; not all curve types are supported. An example of importing a low-polygon STL through trimesh is in zencad/examples/Integration/trimesh. Export details.