fix(multiphysics): add delegation for necessary properties of a Simulation with MultiPhysicsMedium structures (#2487)

* fix: add delegation for _has_incompatibilities to MultiPhysicsMedium

* fix tests for MultiPhysicsMedium simulation

* extend test for MultiPhysicsMedium simulation slightly

* fix: cover more cases for the multiphysicsmedium delegation

* add multiphysicsmedium structure to full simulation test fixture to increase test coverage

Author: frederikschubertflex

tests/test_components/test_simulation.py

@@ -3566,3 +3566,66 @@ def test_sim_volumetric_structures_with_lumped_elements(tmp_path):
         vol_structures = sim.volumetric_structures
         assert len(vol_structures) == 2
         assert np.isclose(vol_structures[1].geometry.bounding_box.size[0], 0, rtol=RTOL)
+
+
+def test_create_sim_multiphysics():
+    s = td.Simulation(
+        run_time=1e-12,
+        size=(10, 10, 10),
+        grid_spec=td.GridSpec(wavelength=1.0),
+        medium=td.Medium(permittivity=1.0),
+        structures=[
+            td.Structure(
+                geometry=td.Box(size=(1, 1, 1), center=(-1, 0.5, 0.5)),
+                medium=td.MultiPhysicsMedium(
+                    optical=td.Medium(permittivity=2.0),
+                    charge=td.ChargeInsulatorMedium(permittivity=2),
+                    name="SiO2",
+                ),
+            ),
+        ],
+    )
+
+
+def test_create_sim_multiphysics_with_incompatibilities():
+    modulated = td.Medium(
+        permittivity=2,
+        modulation_spec=td.ModulationSpec(
+            permittivity=td.SpaceTimeModulation(
+                time_modulation=td.ContinuousWaveTimeModulation(freq0=1e12, amplitude=1.1, phase=0),
+            )
+        ),
+    )
+    assert modulated._has_incompatibilities
+
+    nonlinear = td.Medium(
+        nonlinear_spec=td.NonlinearSpec(
+            models=[
+                td.NonlinearSusceptibility(chi3=1.5),
+                td.TwoPhotonAbsorption(beta=1, sigma=1, tau=1, e_e=1, e_h=0.8, c_e=1, c_h=1),
+                td.KerrNonlinearity(n2=1),
+            ],
+            num_iters=20,
+        )
+    )
+    with pytest.raises(pydantic.ValidationError):
+        s = td.Simulation(
+            run_time=1e-12,
+            size=(10, 10, 10),
+            grid_spec=td.GridSpec(wavelength=1.0),
+            medium=td.Medium(permittivity=1.0),
+            structures=[
+                td.Structure(
+                    geometry=td.Box(size=(1, 1, 1), center=(-1, 0.5, 0.5)),
+                    medium=nonlinear,
+                ),
+                td.Structure(
+                    geometry=td.Box(size=(1, 1, 1), center=(-1, 0.5, 0.5)),
+                    medium=td.MultiPhysicsMedium(
+                        optical=modulated,
+                        charge=td.ChargeInsulatorMedium(permittivity=2),
+                        name="SiO2",
+                    ),
+                ),
+            ],
+        )

tests/utils.py

@@ -664,6 +664,14 @@ def make_custom_data(lims, unstructured):
             medium=td.Medium(permittivity=1.5),
             name="transformed_box",
         ),
+        td.Structure(
+            geometry=td.Box(size=(1, 1, 1), center=(1, 1, 1)),
+            medium=td.MultiPhysicsMedium(
+                optical=td.Medium(permittivity=4.0),
+                charge=td.ChargeInsulatorMedium(permittivity=2),
+                name="SiO2",
+            ),
+        ),
     ],
     sources=[
         td.UniformCurrentSource(

tidy3d/components/material/multi_physics.py

@@ -139,11 +139,28 @@ def __getattr__(self, name: str):
             return None
 
         DELEGATED_ATTRIBUTES = {
-            "is_pec": self.optical,
             "_eps_plot": self.optical,
             "viz_spec": self.optical,
+            "eps_diagonal_numerical": self.optical,
+            "eps_complex_to_nk": self.optical,
+            "nonlinear_spec": self.optical,
+            "is_pec": self.optical,
+            "is_time_modulated": self.optical,
+            "is_nonlinear": self.optical,
+            "is_fully_anisotropic": self.optical,
+            "is_custom": self.optical,
+            "is_isotropic": self.optical,
+            "is_spatially_uniform": self.optical,
+            "_incompatible_material_types": self.optical,
+            "frequency_range": self.optical,
+            "eps_model": self.optical,
         }
 
+        if name == "_has_incompatibilities":
+            return (self.optical and self.optical._has_incompatibilities) or (
+                self.charge and self.charge._has_incompatibilities
+            )
+
         if name in DELEGATED_ATTRIBUTES:
             sub = DELEGATED_ATTRIBUTES[name]
             if sub is None: