Free function API

警告

The free function API is experimental and may change.

For situations when more freedom in crafting individual objects is required, a free function API is provided. This API has no hidden state, but may result in more verbose code. One can still use selectors as methods, but all other operations are implemented as free functions. Placement of objects and creation of patterns can be achieved using the various overloads of the moved method.

Currently this documentation is incomplete, more examples can be found in the tests.

Tutorial

The purpose of this section is to demonstrate how to construct Shape objects using the free function API.

from cadquery.func import *

dh = 2
r = 1

# construct edges
edge1 = circle(r)
edge2 = circle(1.5*r).moved(z=dh)
edge3 = circle(r).moved(z=1.5*dh)

# loft the side face
side = loft(edge1, edge2, edge3)

# bottom face
bottom = fill(side.edges('<Z'))

# top face with continuous curvature
top = cap(side.edges('>Z'), side, [(0,0,1.6*dh)])

# assemble into a solid
s = solid(side, bottom, top)

# construct the final result
result = s.moved((-3*r, 0, 0), (3*r, 0, 0))

The code above builds a non-trivial object by sequentially constructing individual faces, assembling them into a solid and finally generating a pattern.

It begins with defining few edges.

edge1 = circle(r)
edge2 = circle(2*r).moved(z=dh)
edge3 = circle(r).moved(z=1.5*dh)

Those edges are used to create the side faces of the final solid using loft().

side = loft(edge1, edge2, edge3)

Once the side is there, cap() and fill() are used to define the top and bottom faces. Note that cap() tries to maintain curvature continuity with respect to the context shape. This is not the case for fill().

# bottom face
bottom = fill(side.edges('<Z'))

# top face with continuous curvature
top = cap(side.edges('>Z'), side, [(0,0,1.75*dh)])

Next, all the faces are assembled into a solid.

s = solid(side, bottom, top)

Finally, the solid is duplicated and placed in the desired locations creating the final compound object. Note various usages of moved().

result = s.moved((-3*r, 0, 0), (3*r, 0, 0))

In general all the operations are implemented as free functions, with the exception of placement and selection which are strictly related to a specific shape.

Primitives

Various 1D, 2D and 3D primitives are supported.

from cadquery.func import *

e = segment((0,0), (0,1))

c = circle(1)

f = plane(1, 1.5)

b = box(1, 1, 1)

result = compound(e, c.move(2), f.move(4), b.move(6))

Boolean operations

Boolean operations are supported and implemented as operators and free functions. In general boolean operations are slow and it is advised to avoid them and not to perform the in a loop. One can for example union multiple solids at once by first combining them into a compound.

from cadquery.func import *

c1 = cylinder(1, 2)
c2 = cylinder(0.5, 3)

f1 = plane(2, 2).move(z=1)
f2 = plane(1, 1).move(z=1)

e1 = segment((0,-2.5, 1), (0,2.5,1))

# union
r1 = c2 + c1
r2 = fuse(f1, f2)

# difference
r3 = c1 - c2
r4 = cut(f1, f2)

# intersection
r5 = c1*c2
r6 = intersect(f1, f2)

# splitting
r7 = (c1 / f1).solids('<Z')
r8 = split(f2, e1).faces('<X')

results = (r1, r2, r3, r4, r5, r6, r7, r8)
result = compound([el.moved(2*i) for i,el in enumerate(results)])

Note that bool operations work on 2D shapes as well.

Shape construction

Constructing complex shapes from simple shapes is possible in various contexts.

from cadquery.func import *

e1 = segment((0,0), (1,0))
e2 = segment((1,0), (1,1))

# wire from edges
r1 = wire(e1, e2)

c1 = circle(1)

# face from a planar wire
r2 = face(c1)

# solid from faces
f1 = plane(1,1)
f2 = f1.moved(z=1)
f3 = extrude(f1.wires(), (0,0,1))

r3 = solid(f1,f2,*f3)

# compound from shapes
s1 = circle(1).moved(ry=90)
s2 = plane(1,1).move(rx=90).move(y=2)
s3 = cone(1,1.5).move(y=4)

r4 = compound(s1, s2, s3)

results = (r1, r2, r3, r4,)
result = compound([el.moved(2*i) for i,el in enumerate(results)])

Operations

Free function API currently supports extrude(), loft(), revolve() and sweep() operations.

from cadquery.func import *

r = rect(1,0.5)
f = face(r, circle(0.2).moved(0.2), rect(0.2, 0.4).moved(-0.2))
c = circle(0.2)
p = spline([(0,0,0), (0,-1,2)], [(0,0,1), (0,-1,1)])

# extrude
s1 = extrude(r, (0,0,2))
s2 = extrude(fill(r), (0,0,1))

# sweep
s3 = sweep(r, p)
s4 = sweep(f, p)

# loft
s5 = loft(r, c.moved(z=2))
s6 = loft(r, c.moved(z=1), cap=True)\

# revolve
s7 = revolve(fill(r), (0.5, 0, 0), (0, 1, 0), 90)

results = (s1, s2, s3, s4, s5, s6, s7)
result = compound([el.moved(2*i) for i,el in enumerate(results)])

Placement

Placement and creation of arrays is possible using move() and moved().

from cadquery.func import *

locs = [(0,-1,0), (0,1,0)]

s = sphere(1).moved(locs)
c = cylinder(1,2).move(rx=15).moved(*locs)

result = compound(s, c.moved(2))

Text

The free function API has extensive text creation capabilities including text on planar curves and text on surfaces.

from cadquery.func import *

from math import pi

# parameters
D = 5
H = 2*D
S = H/10
TH = S/10
TXT = "CadQuery"

# base and spine
c = cylinder(D, H).moved(rz=-135)
cf = c.faces("%CYLINDER")
spine = (c*plane().moved(z=D)).edges().trim(pi/2, pi)

# planar
r1 = text(TXT, 1, spine, planar=True).moved(z=-S)

# normal
r2 = text(TXT, 1, spine)

# projected
r3 = text(TXT, 1, spine, cf).moved(z=S)

# projected and thickened
r4 = offset(r3, TH).moved(z=S)

result = compound(r1, r2, r3, r4)

Adding features manually

In certain cases it is desirable to add features such as holes or protrusions manually. E.g., for complicated shapes it might be beneficial performance-wise because it avoids boolean operations. One can add or remove faces, add holes to existing faces and last but not least reconstruct existing solids.

from cadquery.func import *

w = 1
r = 0.9*w/2

# box
b = box(w, w, w)
# bottom face
b_bot = b.faces('<Z')
# top faces
b_top = b.faces('>Z')

# inner face
inner = extrude(circle(r), (0,0,w))

# add holes to the bottom and top face
b_bot_hole = b_bot.addHole(inner.edges('<Z'))
b_top_hole = b_top.addHole(inner.edges('>Z'))

# construct the final solid
result = solid(
    b.remove(b_top, b_bot).faces(), #side faces
    b_bot_hole, # bottom with a hole
    inner, # inner cylinder face
    b_top_hole, # top with a hole
)

If the base shape is more complicated, it is possible to use local sewing that takes into account on indicated elements of the context shape. This, however, necessitates a two step approach - first a shell needs to be explicitly sewn and only then the final solid can be constructed.

from cadquery.func import *

w = 1
h = 0.1
r = 0.9*w/2

# box
b = box(w, w, w)
# top face
b_top = b.faces('>Z')

# protrusion
feat_side = extrude(circle(r).moved(b_top.Center()), (0,0,h))
feat_top = face(feat_side.edges('>Z'))
feat = shell(feat_side, feat_top) # sew into a shell

# add hole to the box
b_top_hole = b_top.addHole(feat.edges('<Z'))
b = b.replace(b_top, b_top_hole)

# local sewing - only two faces are taken into account
sh = shell(b_top_hole, feat.faces('<Z'), ctx=(b, feat))
# construct the final solid
result = solid(sh)

Mapping onto parametric space

To complement functionalities described, it is possible to trim edges and faces explicitly using simple rectangular trims, polygons, splines or arbitrary wires.

from math import pi
from cadquery.func import cylinder, edgeOn, compound, wire

# parameters
d = 1.5
h = 3
du = pi
Nturns = 2

# construct the base surface
base = cylinder(d, h).faces("%CYLINDER")

# rectangular trim
r1 = base.trim(-pi/2, 0, 0, h/3)

# polyline trim
r2 = base.trim((0,0), (pi,0), (pi/2, h/2))

# construct a pcurve
pcurve = edgeOn(base, [(pi/2, h/4), (pi, h/4), (pi, h/2), (pi/2, h/2)], periodic=True)

# pcurve trim
r3 = base.trim(wire(pcurve))

result = compound(r1, r2.moved(x=2), r3.moved(x=4))

This in principle allows to model arbitrary shapes in the parametric domain, but often it is more desirable to work with higher level objects like wires.

from cadquery.func import cylinder, loft, wireOn, segment
from math import pi

# parameters
d = 1.5
h = 3
du = pi
Nturns = 2

# construct the base surface
base = cylinder(d, h).faces("%CYLINDER")

# construct a planar 2D patch for u,v trimming
uv_patch = loft(
    segment((0, 0), (du, 0)), segment((Nturns * 2 * pi, h), (Nturns * 2 * pi + du, h))
)

# map it onto the cylinder
w = wireOn(base, uv_patch)

# check that the pcurves were created
for e in w:
    assert e.hasPCurve(base), "No p-curve on base present"

# trim the base surface
result = base.trim(w)

Finally, it is also possible to map complete faces.

from cadquery.func import sphere, text, faceOn

base = sphere(5).faces()

result = faceOn(base, text("CadQuery", 1))