OpenSolid

OpenSolid is an under-development 2D/3D CAD library. This package contains its official Python bindings. The bindings (and OpenSolid itself) are still under active development, but you’re welcome to try them out!

The package contains a single opensolid module containing a variety of classes representing geometric values and quantities, such as Length, Angle, Point2d, and Direction2d. Each class and function has a brief docstring, but here’s a brief sampling of some of the operations you can do:

>>> from opensolid import *

# Define some Length values
>>> width = Length.meters(5)
>>> height = Length.centimeters(10)

# Multiply those to get an Area value
>>> width * height
Area.square_meters(0.5)

# All values are stored in SI units internally,
# so you can mix and match units freely
>>> Length.centimeters(100) + Length.inches(10)
Length.meters(1.254)

# You can request that any length be converted into
# a value in specific units (giving back a plain 'float')
>>> Length.meters(2).in_inches()
78.74015748031496

# Define a couple of points in 2D from their
# X and Y coordinates, given in centimeters
>>> p1 = Point2d.centimeters(50, 60)
>>> p2 = Point2d.centimeters(100, 80)

# Measure the distance between the points
>>> p1.distance_to(p2)
Length.meters(0.5385164807134505)

# Build up a parametric curve (expression);
# 'Curve.t' is the curve parameter, which
# ranges from 0 to 1, so here x will range
# from 0 to 5.
>>> x = 5 * Curve.t
>>> y = x.squared() - 5 * x + 1

# Evaluate the curve at t=0.5
>>> y.evaluate(0.5)
-5.25

# Find the values of t for which y=0. For this, we need
# to set up a tolerance value. (A tolerance is needed
# for cases where e.g. the curve decreases to a tiny
# value like 1e-9 before increasing again; should that
# be considered a solution or not? Similarly, if the
# curve decreases to -1e9 and then increases again,
# should that be considered two zeros or just one? See
# the documentation of Curve.zeros for more info.)
>>> with Tolerance(1e-6):
...     # Get the location of each zero, i.e. the
...     # value of t (not x!) for which y is zero
...     roots = [zero.location() for zero in y.zeros()]
>>> roots
[0.041742430504416, 0.9582575694955838]

# Find the values of x at which y is zero,
# by evaluating x at those roots
>>> [x.evaluate(t) for t in roots]
[0.20871215252208, 4.7912878474779195]

# Check that y is in fact zero at those roots
>>> [y.evaluate(root) for root in roots]
[0.0, 0.0]

# Construct a displacement (vector with length units)
# from its components in meters
>>> d = Displacement2d.meters(1, 2)

# To get the direction of a vector, we also need to
# define a tolerance (any vector with magnitude
# smaller than this value will be considered 'zero'
# and therefore have no direction, so attempting to
# get its direction will raise an exception).
>>> with Tolerance(Length.nanometer):
...     d.direction()
Direction2d.degrees(63.434948822922)