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How to set special variables $fa, $fs, $fn in solidpython

in a previous thread is shown, how to create a 3D-body and save it to an stl-file by solidpython. As $fa, $fs, $fn are not set they have the default values and the 3D-body has a low number of facets. The example code from the thread above:

from solid import *
from subprocess import run

d = difference()(
   cube(10),
   sphere(15)
)

scad_render_to_file(d, 'd.scad')

run(["openscad", "-o",  "d.stl", "d.scad"])

Here the resulting stl-body enter image description here In the documentation i didn‘t find anything about setting these variables. This readme seems to be obsolete.

How can i set $fa, $fs, $fn in solidpython?

Solution

  • There are two ways to do it.

    In solidpython some objects (eg. circle(), sphere(), cylinder()) have the optional parameter segments corresponding to $fn in openscad, see the source code in the file objects.py in the solidpython package (on archlinux /usr/lib/python/site-packages/solid/objects.py).

    possible solidpython code:

    sphere(15, segments = 180)

    resulting openscad code:

    sphere($fn = 180, r = 15);

    Alternatively a file header can be set in scad_render_to_file(), see the source code in the file solidpython.py in the solidpython package.

    solidpython code:

    scad_render_to_file(d, 'd.scad', file_header = '$fa = 0.1;\n$fs = 0.1;', include_orig_code=True)

    writes these lines to the top of the openscad file:

    $fa = 0.1;
$fs = 0.1;

    and here the resulting stl from the example enter image description here