Special Variables

PythonSCAD uses global Python variables instead of OpenSCAD's $-prefixed special variables.

fn

Number of segments used to approximate curves (circles, spheres, cylinders, etc.). Setting fn overrides fa and fs. Equivalent to OpenSCAD's $fn.

Python

from openscad import *

fn = 100
circle(10).show()  # high-resolution circle

fn = 6
circle(10).show()  # hexagon

You can also pass fn as a keyword argument to individual functions:

Python

from openscad import *

circle(10, fn=100).show()

OpenSCAD reference: $fn

fa

Minimum angle in degrees for each segment of a curve. Smaller values produce smoother curves. Equivalent to OpenSCAD's $fa.

Python

from openscad import *

fa = 1  # very smooth curves
sphere(10).show()

OpenSCAD reference: $fa

fs

Minimum circumferential length for each segment of a curve. Smaller values produce smoother curves on larger objects. Equivalent to OpenSCAD's $fs.

Python

from openscad import *

fs = 0.5  # fine detail
sphere(10).show()

OpenSCAD reference: $fs

time

Animation time step, ranging from 0 to 1. Updated by PythonSCAD's animation system. Equivalent to OpenSCAD's $t.

Python

from openscad import *

cube(10).rotate([0, 0, time * 360]).show()

phi

Convenience variable equal to 2 * PI * time. Useful for smooth cyclic animations.

Python

from openscad import *
from math import sin

r = 5 + 3 * sin(phi)
sphere(r).show()