Python Specialities

Special Variables

In Python the well known $fn, $fa and $fs don't exist. Generally there are no $ variables needed as python variables can be overwritten any time. To access $fn, $fa, $fs, simply set global fn, fa, fs variable respectively.

Import existing files

'import()' cannnot be reused in python-openscad as its a python keyword. use 'osimport()' instead.

Storing Data with Solids

It's possible to store arbitrary data along with solids

Python

from openscad import *

# Create the cube object, and store it in variable "c"
c = cube([10,10,2])

# give it a name
c['name']="Fancy cube"

# specify coordinates
c['top_middle']=[5,5,2]

# alternatively same effect has
c.top_middle=[5,5,2]

# Display the cube
show(c)

# Retrieve  Data
print("The Name of the Cube is ",(c['name']))

Object handles

Special application of storing data with objects are handles, which are 4x4 Eigen matrices. Each object has a handle called 'origin' which is identity matrix at first. You can use all the transformations to objects and also to handles like this:

Python

from openscad import *
c=cube([10,10,10])

# translate the origin with an offset, so top_center sits on top of the cube
c.top_center=translate(c.origin,[5,5,10])

# This one even points to the right side
c.right_center=translate(roty(c.origin,90),[10,5,5])

# The handles can be used with align
cyl = cylinder(d=1,h=2)

# This placecs cyl onto the right side of the cube - of course rotated
#    obj       source handle  dest handle
c |= cyl.align(c.right_center,cyl.origin)

c.show()

Object oriented coding style

Most of the Object manipulation function are available in two different flavors: functions and methods.

Python

from openscad import *

# Create a green cube with functions
cu=cube(3)
cu_green=color(cu,"green")
# or simply:
#cu_green = color(cube(10),"green")

# Now create a red sphere using methods
sp=sphere(r=2)
sp_red = sp.color("red")
# or simply:
# sp_red = sphere(r=2).color("red")

# the methods version seems to be more readable

# Now show everything

# use solids in lists to implicitly union them
show([sp_red, cu_green.translate([10,0,0] ) ])