Assembly toCompound (#726)

* Added Assembly.toCompound

* spelling

Co-authored-by: Jeremy Wright <[email protected]>

* Add annotation + minor updates

* Better annotations for locate and move

Co-authored-by: Jeremy Wright <[email protected]>
Co-authored-by: Adam Urbańczyk <[email protected]>

Author: 3 people

cadquery/assembly.py

@@ -4,7 +4,7 @@
 from uuid import uuid1 as uuid
 
 from .cq import Workplane
-from .occ_impl.shapes import Shape, Face, Edge, Wire
+from .occ_impl.shapes import Shape, Compound, Face, Edge, Wire
 from .occ_impl.geom import Location, Vector, Plane
 from .occ_impl.assembly import Color
 from .occ_impl.solver import (
@@ -508,3 +508,14 @@ def _flatten(self, parents=[]):
         rv[PATH_DELIM.join(parents + [self.name])] = self
 
         return rv
+
+    def toCompound(self) -> Compound:
+        """
+        Returns a Compound made from this Assembly (including all children) with the
+        current Locations applied. Usually this method would only be used after solving.
+        """
+
+        shapes = self.shapes
+        shapes.extend((child.toCompound() for child in self.children))
+
+        return Compound.makeCompound(shapes).locate(self.loc)

cadquery/occ_impl/shapes.py

@@ -899,7 +899,7 @@ def location(self) -> Location:
 
         return Location(self.wrapped.Location())
 
-    def locate(self, loc: Location) -> "Shape":
+    def locate(self: T, loc: Location) -> T:
         """
         Apply a location in absolute sense to self
         """
@@ -918,7 +918,7 @@ def located(self, loc: Location) -> "Shape":
 
         return r
 
-    def move(self, loc: Location) -> "Shape":
+    def move(self: T, loc: Location) -> T:
         """
         Apply a location in relative sense (i.e. update current location) to self
         """

tests/test_assembly.py

@@ -391,3 +391,42 @@ def resulting_plane(shape0):
 
     # solid should fail
     fail_this(cq.Solid.makeBox(1, 1, 1))
+
+
+def test_toCompound(simple_assy, nested_assy):
+
+    c0 = simple_assy.toCompound()
+    assert isinstance(c0, cq.Compound)
+    assert len(c0.Solids()) == 4
+
+    c1 = nested_assy.toCompound()
+    assert isinstance(c1, cq.Compound)
+    assert len(c1.Solids()) == 4
+
+    # check nested assy location appears in compound
+    # create four boxes, stack them on top of each other, check highest face is in final compound
+    box0 = cq.Workplane().box(1, 1, 3, centered=(True, True, False))
+    box1 = cq.Workplane().box(1, 1, 4)
+    box2 = cq.Workplane().box(1, 1, 5)
+    box3 = cq.Workplane().box(1, 1, 6)
+    # top level assy
+    assy0 = cq.Assembly(box0, name="box0")
+    assy0.add(box1, name="box1")
+    assy0.constrain("box0@faces@>Z", "box1@faces@<Z", "Plane")
+    # subassy
+    assy1 = cq.Assembly()
+    assy1.add(box2, name="box2")
+    assy1.add(box3, name="box3")
+    assy1.constrain("box2@faces@>Z", "box3@faces@<Z", "Plane")
+    assy1.solve()
+    assy0.add(assy1, name="assy1")
+    assy0.constrain("box1@faces@>Z", "assy1/box2@faces@<Z", "Plane")
+    # before solving there should be no face with Center = (0, 0, 18)
+    c2 = assy0.toCompound()
+    assert not cq.Vector(0, 0, 18) in [x.Center() for x in c2.Faces()]
+    # after solving there should be a face with Center = (0, 0, 18)
+    assy0.solve()
+    c3 = assy0.toCompound()
+    assert cq.Vector(0, 0, 18) in [x.Center() for x in c3.Faces()]
+    # also check with bounding box
+    assert c3.BoundingBox().zlen == pytest.approx(18)