Merge pull request #413 from CadQuery/shell-joint-type

Expose intersection joint type for shell

cadquery/cq.py

@@ -1080,14 +1080,17 @@ def translate(self, vec: VectorLike) -> "Workplane":
  ]
  )
 
- def shell(self, thickness: float) -> "Workplane":
+ def shell(
+ self, thickness: float, kind: Literal["arc", "intersection"] = "arc"
+ ) -> "Workplane":
  """
  Remove the selected faces to create a shell of the specified thickness.
 
  To shell, first create a solid, and *in the same chain* select the faces you wish to remove.
 
  :param thickness: a positive float, representing the thickness of the desired shell.
  Negative values shell inwards, positive values shell outwards.
+ :param kind: kind of joints, intersetion or arc (default: arc).
  :raises: ValueError if the current stack contains objects that are not faces of a solid
  further up in the chain.
  :returns: a CQ object with the resulting shelled solid selected.
@@ -1120,7 +1123,7 @@ def shell(self, thickness: float) -> "Workplane":
 
  faces = [f for f in self.objects if isinstance(f, Face)]
 
- s = solidRef.shell(faces, thickness)
+ s = solidRef.shell(faces, thickness, kind=kind)
  return self.newObject([s])
 
  def fillet(self, radius: float) -> "Workplane":

cadquery/occ_impl/shapes.py

@@ -1665,6 +1665,7 @@ def shell(
  faceList: Iterable[Face],
  thickness: float,
  tolerance: float = 0.0001,
+ kind: Literal["arc", "intersection"] = "arc",
  ) -> Any:
  """
  make a shelled solid of given by removing the list of faces
@@ -1675,22 +1676,37 @@ def shell(
  :return: a shelled solid
  """
 
+ kind_dict = {
+ "arc": GeomAbs_JoinType.GeomAbs_Arc,
+ "intersection": GeomAbs_JoinType.GeomAbs_Intersection,
+ }
+
  occ_faces_list = TopTools_ListOfShape()
 
  if faceList:
  for f in faceList:
  occ_faces_list.Append(f.wrapped)
 
  shell_builder = BRepOffsetAPI_MakeThickSolid(
- self.wrapped, occ_faces_list, thickness, tolerance, Intersection=True
+ self.wrapped,
+ occ_faces_list,
+ thickness,
+ tolerance,
+ Intersection=True,
+ Join=kind_dict[kind],
  )
 
  shell_builder.Build()
  rv = shell_builder.Shape()
 
  else: # if no faces provided a watertight solid will be constructed
  shell_builder = BRepOffsetAPI_MakeThickSolid(
- self.wrapped, occ_faces_list, thickness, tolerance, Intersection=True
+ self.wrapped,
+ occ_faces_list,
+ thickness,
+ tolerance,
+ Intersection=True,
+ Join=kind_dict[kind],
  )
 
  shell_builder.Build()

tests/test_cadquery.py

@@ -1828,9 +1828,21 @@ def testSimpleShell(self):
  """
  Create s simple box
  """
- s = Workplane("XY").box(2, 2, 2).faces("+Z").shell(0.05)
- self.saveModel(s)
- self.assertEqual(23, s.faces().size())
+ s1 = Workplane("XY").box(2, 2, 2).faces("+Z").shell(0.05)
+ self.saveModel(s1)
+ self.assertEqual(23, s1.faces().size())
+
+ s2 = (
+ Workplane()
+ .ellipse(4, 2)
+ .extrude(4)
+ .faces(">Z")
+ .shell(+2, kind="intersection")
+ )
+ self.assertEqual(5, s2.faces().size())
+
+ s3 = Workplane().ellipse(4, 2).extrude(4).faces(">Z").shell(+2, kind="arc")
+ self.assertEqual(6, s3.faces().size())
 
  def testClosedShell(self):
  """