Geometry.zero_dims method that speeds up the validator for zero-sized geometries

Author: momchil-flex

CHANGELOG.md

@@ -7,6 +7,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ## [Unreleased]
 
 ### Added
+- `Geometry.zero_dims` method that uses `Geometry.bounds` and speeds up the validator for zero-sized geometries.
 
 ### Changed
 - Limited number of distinct sources to 1000. In cases where a complicated spatial dependence of the source is desired, a ``CustomFieldSource`` or a ``CustomCurrentSource`` can be used instead of multiple distinct sources.

tidy3d/components/geometry/base.py

@@ -272,6 +272,15 @@ def bounding_box(self):
         """
         return Box.from_bounds(*self.bounds)
 
+    @cached_property
+    def zero_dims(self) -> List[Axis]:
+        """A list of axes along which the :class:`Geometry` is zero-sized based on its bounds."""
+        zero_dims = []
+        for dim in range(3):
+            if self.bounds[1][dim] == self.bounds[0][dim]:
+                zero_dims.append(dim)
+        return zero_dims
+
     def _pop_bounds(self, axis: Axis) -> Tuple[Coordinate2D, Tuple[Coordinate2D, Coordinate2D]]:
         """Returns min and max bounds in plane normal to and tangential to ``axis``.
 

tidy3d/components/simulation.py

@@ -527,11 +527,11 @@ def _validate_2d_geometry_has_2d_medium(cls, val, values):
             if isinstance(structure.medium, Medium2D):
                 continue
             for geom in flatten_groups(structure.geometry):
-                zero_axes = [ind for ind, ele in enumerate(geom.bounding_box.size) if ele == 0.0]
-                if len(zero_axes) > 0:
+                zero_dims = geom.zero_dims
+                if len(zero_dims) > 0:
                     log.warning(
                         f"Structure at 'structures[{i}]' has geometry with zero size along "
-                        f"dimensions {zero_axes}, and with a medium that is not a 'Medium2D'. "
+                        f"dimensions {zero_dims}, and with a medium that is not a 'Medium2D'. "
                         "This is probably not correct, since the resulting simulation will "
                         "depend on the details of the numerical grid. Consider either "
                         "giving the geometry a nonzero thickness or using a 'Medium2D'."