Merge pull request #116 from fusion-energy/adding_scaling_option_when…

…_adding_cadquery_object

Adding scaling option when adding cadquery objects

src/cad_to_dagmc/core.py

@@ -503,6 +503,7 @@ def add_cadquery_object(
             cq.assembly.Assembly | cq.occ_impl.shapes.Compound | cq.occ_impl.shapes.Solid
         ),
         material_tags: list[str] | None,
+        scale_factor: float = 1.0,
     ) -> int:
         """Loads the parts from CadQuery object into the model.
 
@@ -514,6 +515,10 @@ def add_cadquery_object(
                 same order as the volumes in the geometry added (STP file and
                 CadQuery objects) and match the material tags used in the
                 neutronics code (e.g. OpenMC).
+            scale_factor: a scaling factor to apply to the geometry that can be
+                used to increase the size or decrease the size of the geometry.
+                Useful when converting the geometry to cm for use in neutronics
+                simulations.
 
         Returns:
             int: number of volumes in the stp file.
@@ -527,12 +532,17 @@ def add_cadquery_object(
         else:
             iterable_solids = cadquery_object.val().Solids()
 
-        _check_material_tags(material_tags, iterable_solids)
+        if scale_factor == 1.0:
+            scaled_iterable_solids = iterable_solids
+        else:
+            scaled_iterable_solids = [part.scale(scale_factor) for part in iterable_solids]
+
+        _check_material_tags(material_tags, scaled_iterable_solids)
         if material_tags:
             self.material_tags = self.material_tags + material_tags
-        self.parts = self.parts + iterable_solids
+        self.parts = self.parts + scaled_iterable_solids
 
-        return len(iterable_solids)
+        return len(scaled_iterable_solids)
 
     def export_unstructured_mesh_file(
         self,

tests/test_python_api.py

@@ -1,16 +1,16 @@
 import os
-from pathlib import Path
-import pytest
-import cadquery as cq
-from cad_to_dagmc import CadToDagmc
 import warnings
-from cad_to_dagmc.core import _check_material_tags
-
 from pathlib import Path
 
+import cadquery as cq
+import gmsh
 import pymoab as mb
+import pytest
 from pymoab import core, types
 
+from cad_to_dagmc import CadToDagmc
+from cad_to_dagmc.core import _check_material_tags
+
 
 def get_volumes_and_materials_from_h5m(filename: str) -> dict:
     """Reads in a DAGMC h5m file and uses PyMoab to find the volume ids with
@@ -219,3 +219,117 @@ def test_check_material_tags_too_long():
         assert issubclass(w[-1].category, UserWarning)
         assert "Material tag" in str(w[-1].message)
         assert "a" * 29 in str(w[-1].message)
+
+
+@pytest.mark.parametrize(
+    "scale_factor, expected_width",
+    [
+        (1, 10.0),
+        (2, 20.0),
+        (10, 100.0),
+    ],
+)
+def test_scaling_factor_when_adding_stp(scale_factor, expected_width):
+
+    c2d = CadToDagmc()
+    c2d.add_stp_file("tests/single_cube.stp", scale_factor=scale_factor)
+    c2d.export_gmsh_mesh_file(f"st_test_scaling_factor_{scale_factor}.msh")
+
+    gmsh.initialize()
+    gmsh.open(f"st_test_scaling_factor_{scale_factor}.msh")
+    _, node_coords, _ = gmsh.model.mesh.getNodes()
+
+    # Reshape the node coordinates into a 2D array
+    node_coords = node_coords.reshape(-1, 3)
+
+    # Calculate the bounding box
+    min_coords = node_coords.min(axis=0)
+    max_coords = node_coords.max(axis=0)
+
+    width_x = max_coords[0] - min_coords[0]
+    width_y = max_coords[1] - min_coords[1]
+    width_z = max_coords[2] - min_coords[2]
+
+    gmsh.finalize()
+
+    assert width_x == expected_width
+    assert width_y == expected_width
+    assert width_z == expected_width
+
+
+@pytest.mark.parametrize(
+    "scale_factor, expected_width",
+    [
+        (1, 10.0),
+        (2, 20.0),
+        (10, 100.0),
+    ],
+)
+def test_scaling_factor_when_adding_cq_object(scale_factor, expected_width):
+
+    box = cq.Workplane("XY").box(10, 10, 10)
+    c2d = CadToDagmc()
+    c2d.add_cadquery_object(box, scale_factor=scale_factor, material_tags=["mat1"])
+    c2d.export_gmsh_mesh_file(f"cq_test_scaling_factor_{scale_factor}.msh")
+
+    gmsh.initialize()
+    gmsh.open(f"cq_test_scaling_factor_{scale_factor}.msh")
+    _, node_coords, _ = gmsh.model.mesh.getNodes()
+
+    # Reshape the node coordinates into a 2D array
+    node_coords = node_coords.reshape(-1, 3)
+
+    # Calculate the bounding box
+    min_coords = node_coords.min(axis=0)
+    max_coords = node_coords.max(axis=0)
+
+    width_x = max_coords[0] - min_coords[0]
+    width_y = max_coords[1] - min_coords[1]
+    width_z = max_coords[2] - min_coords[2]
+
+    gmsh.finalize()
+
+    assert width_x == expected_width
+    assert width_y == expected_width
+    assert width_z == expected_width
+
+
+@pytest.mark.parametrize(
+    "scale_factor, expected_x_width, expected_y_width, expected_z_width",
+    [
+        (1, 20.0, 10.0, 10.0),
+        (2, 40.0, 20.0, 20.0),
+        (10, 200.0, 100.0, 100.0),
+    ],
+)
+def test_two_box_scaling_factor_when_adding_cq_object(
+    scale_factor, expected_x_width, expected_y_width, expected_z_width
+):
+
+    box = cq.Workplane("XY").box(10, 10, 10)
+    box2 = cq.Workplane("XY").moveTo(10, 0).box(10, 10, 10)
+    c2d = CadToDagmc()
+    c2d.add_cadquery_object(box, scale_factor=scale_factor, material_tags=["mat1"])
+    c2d.add_cadquery_object(box2, scale_factor=scale_factor, material_tags=["mat1"])
+    c2d.export_gmsh_mesh_file(f"cq_test_2_box_scaling_factor_{scale_factor}.msh")
+
+    gmsh.initialize()
+    gmsh.open(f"cq_test_2_box_scaling_factor_{scale_factor}.msh")
+    _, node_coords, _ = gmsh.model.mesh.getNodes()
+
+    # Reshape the node coordinates into a numpy 2D array
+    node_coords = node_coords.reshape(-1, 3)
+
+    # Calculate the bounding box
+    min_coords = node_coords.min(axis=0)
+    max_coords = node_coords.max(axis=0)
+
+    width_x = max_coords[0] - min_coords[0]
+    width_y = max_coords[1] - min_coords[1]
+    width_z = max_coords[2] - min_coords[2]
+
+    gmsh.finalize()
+
+    assert width_x == expected_x_width
+    assert width_y == expected_y_width
+    assert width_z == expected_z_width