Add priority to structure

Author: weiliangjin2021

Diff for: tidy3d/components/scene.py

@@ -24,7 +24,7 @@
 from tidy3d.components.tcad.doping import ConstantDoping, GaussianDoping
 from tidy3d.components.tcad.viz import HEAT_SOURCE_CMAP
 
-from ..constants import CONDUCTIVITY, LARGE_NUMBER, THERMAL_CONDUCTIVITY, inf
+from ..constants import CONDUCTIVITY, THERMAL_CONDUCTIVITY, inf
 from ..exceptions import SetupError, Tidy3dError
 from ..log import log
 from .base import Tidy3dBaseModel, cached_property
@@ -43,7 +43,6 @@
     AbstractCustomMedium,
     AbstractMedium,
     AbstractPerturbationMedium,
-    LossyMetalMedium,
     Medium,
     Medium2D,
 )
@@ -56,7 +55,7 @@
     InterpMethod,
     LengthUnit,
     PermittivityComponent,
-    OverlappingPriority,
+    PriorityMode,
     Shapely,
     Size,
 )
@@ -108,19 +107,20 @@ class Scene(Tidy3dBaseModel):
         (),
         title="Structures",
         description="Tuple of structures present in scene. "
-        "Note: In regions of spatial overlapping between structures, "
-        "material properties are dictated by structure of higher priority "
-        "defined by ``overlapping_priority``.",
+        "Note: In regions of spatial overlap between structures, "
+        "material properties are dictated by structure of higher priority. "
+        "The priority for structure of `priority=None` is set automatically "
+        "from `structure_priority_mode`. For structures of equal priority, "
+        "the structure added later to the structure list takes precedence.",
     )
 
-    overlapping_priority: OverlappingPriority = pd.Field(
-        "latter",
-        title="Resolution Strategy In Structure Overlapping Region",
-        description="In regions of spatial overlapping between structures, "
-        "if ``overlapping_priority=latter``, structures defined later in the list haver higher "
-        "priority. If ``overlapping_priority=metal``, metallic structures of higher conductivity "
-        "have higher priority; when the structures are of the same priority from material perspecive, "
-        "the one defined later in the list has higher priority.",
+    structure_priority_mode: PriorityMode = pd.Field(
+        "equal",
+        title="Automatic Structure Priority Setup",
+        description="This field only affects structures of `priority=None`. "
+        "If `equal`, the priority of those structures is set to 0; if `conductor`, "
+        "the priority of structures made of `LossyMetalMedium` is set to 90, "
+        "`PECMedium` to 100, and others to 0.",
     )
 
     plot_length_units: Optional[LengthUnit] = pd.Field(
@@ -260,31 +260,18 @@ def medium_map(self) -> Dict[StructureMediumType, pd.NonNegativeInt]:
 
     @cached_property
     def sorted_structures(self) -> List[Structure]:
-        """Returns a list of sorted structures based on the priority strategy when structures
-        overlap. In the sorted list, latter added structures take higher priority.
+        """Returns a list of sorted structures based on their priority.In the sorted list,
+        latter added structures take higher priority.
 
         Returns
         -------
         List[:class:`.Structure`]
         """
 
-        if self.overlapping_priority == "latter":
-            return self.structures
-
-        # The other strategy is "metal":
-        #   Prioritize metallic structures including LossyMetal and PEC. When two metallic structures overlap,
-        #   prioritize the structure of higher conductivity.
         def structure_comparator(struct1, struct2):
-            mat_list = [struct1.medium, struct2.medium]
-            # For implementation convenience, let's denote conductivity of regular medium as -1,
-            # so that it's lower than that of any metal.
-            sigmas = [-1, -1]
-            for ind, mat in enumerate(mat_list):
-                if mat.is_pec:
-                    sigmas[ind] = LARGE_NUMBER
-                elif isinstance(mat, LossyMetalMedium):
-                    sigmas[ind] = mat.conductivity
-            return sigmas[0] - sigmas[1]
+            return struct1._priority(self.structure_priority_mode) - struct2._priority(
+                self.structure_priority_mode
+            )
 
         return sorted(self.structures, key=cmp_to_key(structure_comparator))
 

Diff for: tidy3d/components/structure.py

@@ -24,9 +24,9 @@
 from .geometry.utils import GeometryType, validate_no_transformed_polyslabs
 from .grid.grid import Coords
 from .material.types import StructureMediumType
-from .medium import AbstractCustomMedium, CustomMedium, Medium, Medium2D
+from .medium import AbstractCustomMedium, CustomMedium, LossyMetalMedium, Medium, Medium2D
 from .monitor import FieldMonitor, PermittivityMonitor
-from .types import TYPE_TAG_STR, Ax, Axis
+from .types import TYPE_TAG_STR, Ax, Axis, PriorityMode
 from .validators import validate_name_str
 from .viz import add_ax_if_none, equal_aspect
 
@@ -75,6 +75,16 @@ class AbstractStructure(Tidy3dBaseModel):
         "``Simulation`` by default to compute the shape derivatives.",
     )
 
+    priority: int = pydantic.Field(
+        None,
+        title="Priority",
+        description="Priority of the structure in structure overlapping region. "
+        "The material property in the overlapping region is dictated by the structure "
+        "of higher priority. For structures of equal priority, "
+        "the structure added later to the structure list takes precedence. When `priority` is None, "
+        "the value is automatically assigned based on `structure_priority_mode` in the `Simulation`.",
+    )
+
     @pydantic.root_validator(skip_on_failure=True)
     def _handle_background_mediums(cls, values):
         """Handle background medium combinations, including deprecation."""
@@ -110,6 +120,14 @@ def _transformed_slanted_polyslabs_not_allowed(cls, val):
         validate_no_transformed_polyslabs(val)
         return val
 
+    def _priority(self, priority_mode: PriorityMode) -> int:
+        """Priority of this structure. The priority value is set automatically based on `priority_modes,
+        if its original value is `None`.
+        """
+        if self.priority is not None:
+            return self.priority
+        return 0
+
     @property
     def viz_spec(self):
         return None
@@ -189,6 +207,20 @@ class Structure(AbstractStructure):
         discriminator=TYPE_TAG_STR,
     )
 
+    def _priority(self, priority_mode: PriorityMode) -> int:
+        """Priority of this structure. The priority value is set automatically based on `priority_modes,
+        if its original value is `None`.
+        """
+        if self.priority is not None:
+            return self.priority
+
+        if priority_mode == "conductor":
+            if self.medium.is_pec:
+                return 100
+            if isinstance(self.medium, LossyMetalMedium):
+                return 90
+        return 0
+
     @property
     def viz_spec(self):
         return self.medium.viz_spec

Diff for: tidy3d/components/types.py

@@ -200,7 +200,7 @@ def __modify_schema__(cls, field_schema):
 ClipOperationType = Literal["union", "intersection", "difference", "symmetric_difference"]
 BoxSurface = Literal["x-", "x+", "y-", "y+", "z-", "z+"]
 LengthUnit = Literal["nm", "μm", "um", "mm", "cm", "m"]
-OverlappingPriority = Literal["metal", "latter"]
+PriorityMode = Literal["equal", "conductor"]
 
 """ medium """