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 'os_import()' instead.

Storing Data along Solids

Its possible to store arbritary 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
output(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 handle called 'origin' which is identity matrix at first. You can use all the transformations to objects and also to handles like so:

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)

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 cylinder with functions
cy=cylinder(r=2,h=10)
cy_green=color(cy,"green")
# or more simple:
# cy_green = color(cylinder(r=2,h=10),"green")

# Now create a red sphere with methods
sp=sphere(r=2)
sp_red = sp.color("red")
# or more simple:
# sp_red = sphere(r=2).color("red")

# method flavor deems to be more readble 

# Now output everything

# use solids in lists to implicitely union them
output([sp_red, cy_green.translate([10,0,0] )
# here is yet another method ....