Class AreaNthSelector

cadquery/selectors.py:472–537

Selects the object(s) with Nth area Applicability: - Faces, Shells, Solids - Shape.Area() is used to compute area - closed planar Wires - a temporary face is created to compute area Will ignore non-planar or non-closed wires. Among other things can be used to sele

class AreaNthSelector(_NthSelector):
    """
    Selects the object(s) with Nth area

    Applicability:
        - Faces, Shells, Solids - Shape.Area() is used to compute area
        - closed planar Wires - a temporary face is created to compute area

    Will ignore non-planar or non-closed wires.

    Among other things can be used to select one of
    the nested coplanar wires or faces.

    For example to create a fillet on a shank::

       result = (
           cq.Workplane("XY")
           .circle(5)
           .extrude(2)
           .circle(2)
           .extrude(10)
           .faces(">Z[-2]")
           .wires(AreaNthSelector(0))
           .fillet(2)
       )

    Or to create a lip on a case seam::

       result = (
           cq.Workplane("XY")
           .rect(20, 20)
           .extrude(10)
           .edges("|Z or <Z")
           .fillet(2)
           .faces(">Z")
           .shell(2)
           .faces(">Z")
           .wires(AreaNthSelector(-1))
           .toPending()
           .workplane()
           .offset2D(-1)
           .extrude(1)
           .faces(">Z[-2]")
           .wires(AreaNthSelector(0))
           .toPending()
           .workplane()
           .cutBlind(2)
       )
    """

    def key(self, obj: Shape) -> float:
        if obj.ShapeType() in ("Face", "Shell", "Solid"):
            return obj.Area()
        elif obj.ShapeType() == "Wire":
            try:
                from cadquery.occ_impl.shapes import Face, Wire

                return abs(Face.makeFromWires(cast(Wire, obj)).Area())