Imprinting and matching

cadquery/occ_impl/assembly.py

@@ -12,7 +12,7 @@
 from OCP.Quantity import Quantity_ColorRGBA
 from OCP.BRepAlgoAPI import BRepAlgoAPI_Fuse
 from OCP.TopTools import TopTools_ListOfShape
-from OCP.BOPAlgo import BOPAlgo_GlueEnum
+from OCP.BOPAlgo import BOPAlgo_GlueEnum, BOPAlgo_MakeConnected
 from OCP.TopoDS import TopoDS_Shape
 
 from vtkmodules.vtkRenderingCore import (
@@ -22,7 +22,7 @@
 )
 
 from .geom import Location
-from .shapes import Shape, Compound
+from .shapes import Shape, Solid, Compound
 from .exporters.vtk import toString
 from ..cq import Workplane
 
@@ -411,3 +411,51 @@ def extract_shapes(assy, parent_loc=None, parent_color=None):
                     color_tool.SetColor(cur_lbl, color.wrapped, XCAFDoc_ColorGen)
 
     return top_level_lbl, doc
+
+
+def imprint(assy: AssemblyProtocol) -> Tuple[Shape, Dict[Shape, Tuple[str, ...]]]:
+
+    # assy iterator
+    def iterate(a, loc=None, name=None):
+
+        name = f"{name}/{a.name}" if name else a.name
+        loc = loc * a.loc if loc else a.loc
+
+        if a.obj:
+            yield a.obj, name, loc
+
+        for ch in a.children:
+            yield from iterate(ch, loc, name)
+
+    # make the id map
+    id_map = {}
+
+    for obj, name, loc in iterate(assy):
+        if isinstance(obj, Shape):
+            tmp = obj.moved(loc)
+        else:
+            tmp = Compound.makeCompound(obj.vals()).moved(loc)
+
+        for s in tmp.Solids():
+            id_map[s] = name
+
+    # connect topologically
+    bldr = BOPAlgo_MakeConnected()
+    bldr.SetRunParallel(True)
+    bldr.SetUseOBB(True)
+
+    for obj in id_map:
+        bldr.AddArgument(obj.wrapped)
+
+    bldr.Perform()
+    res = Shape(bldr.Shape())
+
+    # make the conneted solid -> id map
+    origins: Dict[Shape, Tuple[str, ...]] = {}
+
+    for s in res.Solids():
+        ids = tuple(id_map[Solid(el)] for el in bldr.GetOrigins(s.wrapped))
+        # if GetOrigins yiels nothing, solid was not modified
+        origins[s] = ids if ids else (id_map[s],)
+
+    return res, origins

environment.yml

@@ -1,11 +1,13 @@
 name: cadquery
 channels:
   - conda-forge
+  - cadquery/dev
   - cadquery
 dependencies:
   - python>=3.8
   - ipython
-  - ocp=7.7.*
+  - ocp=7.7.1.*
+  - python-gmsh
   - pyparsing>=2.1.9
   - sphinx=5.0.1
   - sphinx_rtd_theme

tests/test_assembly.py

@@ -1475,3 +1475,42 @@ def test_point_constraint(simple_assy2):
     t2 = assy.children[1].loc.wrapped.Transformation().TranslationPart()
 
     assert t2.Modulus() == pytest.approx(1)
+
+
+@pytest.fixture
+def touching_assy():
+
+    b1 = cq.Workplane().box(1, 1, 1)
+    b2 = cq.Workplane(origin=(1, 0, 0)).box(1, 1, 1)
+
+    return cq.Assembly().add(b1).add(b2)
+
+
+@pytest.fixture
+def disjoint_assy():
+
+    b1 = cq.Workplane().box(1, 1, 1)
+    b2 = cq.Workplane(origin=(2, 0, 0)).box(1, 1, 1)
+
+    return cq.Assembly().add(b1).add(b2)
+
+
+def test_imprinting(touching_assy, disjoint_assy):
+
+    # normal usecase
+    r, o = cq.occ_impl.assembly.imprint(touching_assy)
+
+    assert len(r.Solids()) == 2
+    assert len(r.Faces()) == 11
+
+    for s in r.Solids():
+        assert s in o
+
+    # edge usecase
+    r, o = cq.occ_impl.assembly.imprint(disjoint_assy)
+
+    assert len(r.Solids()) == 2
+    assert len(r.Faces()) == 12
+
+    for s in r.Solids():
+        assert s in o