Merge pull request #99 from fusion-energy/adding-scaling-factor

adding scale_factor that scales mesh

.github/workflows/ci_with_conda_install.yml

@@ -62,3 +62,4 @@ jobs:
           python examples/surface_mesh/from_gmsh_mesh_file.py
           python examples/unstrucutred_volume_mesh/curved_cadquery_object_to_dagmc_volume_mesh.py
           python examples/unstrucutred_volume_mesh/simulate_unstrucutred_volume_mesh_with_openmc.py
+          python examples/surface_mesh/cadquery_assembly_with_scaled_geometry.py

.github/workflows/ci_with_pip_install.yml

@@ -58,3 +58,4 @@ jobs:
           python examples/surface_mesh/from_gmsh_mesh_file.py
           python examples/unstrucutred_volume_mesh/curved_cadquery_object_to_dagmc_volume_mesh.py
           python examples/unstrucutred_volume_mesh/simulate_unstrucutred_volume_mesh_with_openmc.py
+          python examples/surface_mesh/cadquery_assembly_with_scaled_geometry.py

examples/surface_mesh/cadquery_assembly.py

@@ -10,4 +10,4 @@
 
 my_model = CadToDagmc()
 my_model.add_cadquery_object(cadquery_object=assembly, material_tags=["mat1", "mat2"])
-my_model.export_dagmc_h5m_file(min_mesh_size=0.5, max_mesh_size=1.0)
+my_model.export_dagmc_h5m_file(min_mesh_size=0.5, max_mesh_size=1.0e6)

examples/surface_mesh/cadquery_assembly_with_scaled_geometry.py

@@ -0,0 +1,14 @@
+import cadquery as cq
+from cad_to_dagmc import CadToDagmc
+
+result = cq.Workplane().sphere(5)
+result2 = cq.Workplane().moveTo(10, 0).sphere(2)
+
+assembly = cq.Assembly()
+assembly.add(result)
+assembly.add(result2)
+
+my_model = CadToDagmc()
+my_model.add_cadquery_object(cadquery_object=assembly, material_tags=["mat1", "mat2"])
+# scales geometry to makie it 10 times bigger
+my_model.export_dagmc_h5m_file(min_mesh_size=0.5, max_mesh_size=1.0e6, scale_factor=10.0)

src/cad_to_dagmc/core.py

@@ -190,16 +190,24 @@ def _vertices_to_h5m(
     return h5m_filename
 
 
-def get_volumes(gmsh, assembly, method="file"):
+def get_volumes(gmsh, assembly, method="file", scale_factor=1.0):
 
     if method == "in memory":
         volumes = gmsh.model.occ.importShapesNativePointer(assembly.wrapped._address())
-        gmsh.model.occ.synchronize()
+
     elif method == "file":
         with tempfile.NamedTemporaryFile(suffix=".step") as temp_file:
             exporters.export(assembly, temp_file.name)
             volumes = gmsh.model.occ.importShapes(temp_file.name)
-            gmsh.model.occ.synchronize()
+
+    # updating the model to ensure the entities in the geometry are found
+    gmsh.model.occ.synchronize()
+
+    if scale_factor != 1.0:
+        dim_tags = gmsh.model.getEntities(3)
+        gmsh.model.occ.dilate(dim_tags, 0.0, 0.0, 0.0, scale_factor, scale_factor, scale_factor)
+        # update the model to ensure the scaling factor has been applied
+        gmsh.model.occ.synchronize()
 
     return gmsh, volumes
 
@@ -478,6 +486,7 @@ def export_unstructured_mesh_file(
         max_mesh_size: float = 5,
         mesh_algorithm: int = 1,
         method: str = "file",
+        scale_factor: float = 1.0,
     ):
 
         assembly = cq.Assembly()
@@ -488,7 +497,7 @@ def export_unstructured_mesh_file(
 
         gmsh = init_gmsh()
 
-        gmsh, _ = get_volumes(gmsh, imprinted_assembly, method=method)
+        gmsh, _ = get_volumes(gmsh, imprinted_assembly, method=method, scale_factor=scale_factor)
 
         gmsh = _mesh_brep(
             gmsh=gmsh,
@@ -517,6 +526,7 @@ def export_gmsh_mesh_file(
         mesh_algorithm: int = 1,
         dimensions: int = 2,
         method: str = "file",
+        scale_factor: float = 1.0,
     ):
         """Saves a GMesh msh file of the geometry in either 2D surface mesh or
         3D volume mesh.
@@ -536,6 +546,9 @@ def export_gmsh_mesh_file(
                 the same as the version used by CadQuery. This is possible to
                 ensure when installing the package with Conda but harder when
                 installing from PyPI.
+            scale_factor: a scaling factor to apply to the geometry that can be
+                used to enlarge or shrink the geometry. Useful when converting
+                Useful when converting the geometry to cm for use in neutronics
         """
 
         assembly = cq.Assembly()
@@ -546,7 +559,7 @@ def export_gmsh_mesh_file(
 
         gmsh = init_gmsh()
 
-        gmsh, _ = get_volumes(gmsh, imprinted_assembly, method=method)
+        gmsh, _ = get_volumes(gmsh, imprinted_assembly, method=method, scale_factor=scale_factor)
 
         gmsh = _mesh_brep(
             gmsh=gmsh,
@@ -570,6 +583,7 @@ def export_dagmc_h5m_file(
         mesh_algorithm: int = 1,
         implicit_complement_material_tag: str | None = None,
         method: str = "file",
+        scale_factor: float = 1.0,
     ) -> str:
         """Saves a DAGMC h5m file of the geometry
 
@@ -590,6 +604,10 @@ def export_dagmc_h5m_file(
                 the same as the version used by CadQuery. This is possible to
                 ensure when installing the package with Conda but harder when
                 installing from PyPI.
+            scale_factor: a scaling factor to apply to the geometry that can be
+                used to enlarge or shrink the geometry. Useful when converting
+                Useful when converting the geometry to cm for use in neutronics
+
         Returns:
             str: the DAGMC filename saved
         """
@@ -618,7 +636,9 @@ def export_dagmc_h5m_file(
 
         gmsh = init_gmsh()
 
-        gmsh, volumes = get_volumes(gmsh, imprinted_assembly, method=method)
+        gmsh, volumes = get_volumes(
+            gmsh, imprinted_assembly, method=method, scale_factor=scale_factor
+        )
 
         gmsh = _mesh_brep(
             gmsh=gmsh,