cq-filter 0.0.1

Cadquery object filtering framework

CadQuery object filtering framework

cq-filter adds a few new workplane methods that take a function argument of type f: Callable[[CQObject], bool]:

• filter(f): filters Workplane objects
• sort(f): orders Workplane objects
• group(f): groups Workplane objects

Additionally, it adds subscription support to the Workplane, allowing selection of objects quickly.

Rationale

Manipulating object selections in cadquery isn't currently possible without breaking out of the fluent API.

Using filter

Following example filters all faces with an Area of more than 100

wp = (
    wp
    .faces(">Z")
    .filter(lambda face: face.Area() > 100)
)

⚠️ values in cq/occt are often not as exact as you'd expect. For example you might expect a certain face to have an area of exactly 100 and be included when you filter the area against >= 100, but upon closer inspection it turns out the area is actually just slightly below 100 (99.999999997). Consider rounding to some sane precision, like round(face.Area(), 4)

Using sort and subscription

Following example sorts all faces by area and selects the three biggest ones

wp = (
    wp
    .faces(">Z")
    .sort(lambda face: face.Area())[-3:]
)

Using group and clustering

Select the smallest faces that are within 10 units of each other

wp = (
    wp
    .faces(">Z")
    .group(Cluster(lambda face: face.Area(), tol=10)[0])
)

• ⚠️group() call will not yet select new objects, but it will create a new workplane object. Selection should be done immediatelly after the grouping. Grouping data will be erased by next manipulation of workplane.

• selecting a range of groups ([0:2]) works as expected

• Cluster() defaults to a tolerance of 1e-4

Usage

You'll probably want to create your own workplane class

class Workplane(CQFilterMixin, cq.Workplane):
   pass