feat: perm monitor, enh. monitors, sim node naming

We greatly enhanced the field, flux monitors, and added the permittivity
monitor.

mobj naming is still a bit borked; we need a node-tree bound namespace
to go further with it.
For now, don't duplicate nodes, and don't use multiple node trees.

src/blender_maxwell/assets/geonodes.py

@@ -75,7 +75,7 @@ class GeoNodes(enum.StrEnum):
 	## Monitor
 	MonitorEHField = '_monitor_eh_field'
 	MonitorPowerFlux = '_monitor_power_flux'
-	MonitorEpsTensor = '_monitor_eps_tensor'
+	MonitorPermittivity = '_monitor_permittivity'
 	MonitorDiffraction = '_monitor_diffraction'
 	MonitorProjCartEHField = '_monitor_proj_eh_field'
 	MonitorProjAngEHField = '_monitor_proj_ang_eh_field'
@@ -186,7 +186,7 @@ class GeoNodes(enum.StrEnum):
 			## Monitor
 			GN.MonitorEHField: GN_INTERNAL_MONITORS_PATH,
 			GN.MonitorPowerFlux: GN_INTERNAL_MONITORS_PATH,
-			GN.MonitorEpsTensor: GN_INTERNAL_MONITORS_PATH,
+			GN.MonitorPermittivity: GN_INTERNAL_MONITORS_PATH,
 			GN.MonitorDiffraction: GN_INTERNAL_MONITORS_PATH,
 			GN.MonitorProjCartEHField: GN_INTERNAL_MONITORS_PATH,
 			GN.MonitorProjAngEHField: GN_INTERNAL_MONITORS_PATH,

src/blender_maxwell/node_trees/maxwell_sim_nodes/contracts/__init__.py

@@ -61,6 +61,7 @@ from .sim_types import (
 	BoundCondType,
 	NewSimCloudTask,
 	SimAxisDir,
+	SimFieldPols,
 	SimSpaceAxis,
 	manual_amp_time,
 )
@@ -104,6 +105,7 @@ __all__ = [
 	'BoundCondType',
 	'NewSimCloudTask',
 	'SimAxisDir',
+	'SimFieldPols',
 	'SimSpaceAxis',
 	'manual_amp_time',
 	'NodeCategory',

src/blender_maxwell/node_trees/maxwell_sim_nodes/contracts/flow_kinds/flow_kinds.py

@@ -120,7 +120,7 @@ class FlowKind(enum.StrEnum):
 			FlowKind.Value: 'Value',
 			FlowKind.Array: 'Array',
 			FlowKind.LazyArrayRange: 'Range',
-			FlowKind.LazyValueFunc: 'Lazy Value',
+			FlowKind.LazyValueFunc: 'Func',
 			FlowKind.Params: 'Parameters',
 			FlowKind.Info: 'Information',
 		}[v]

src/blender_maxwell/node_trees/maxwell_sim_nodes/contracts/sim_types.py

@@ -169,6 +169,52 @@ class SimAxisDir(enum.StrEnum):
 		return {SAD.Plus: True, SAD.Minus: False}[self]
 
 
+####################
+# - Simulation Fields
+####################
+class SimFieldPols(enum.StrEnum):
+	"""Positive or negative direction along an injection axis."""
+
+	Ex = 'Ex'
+	Ey = 'Ey'
+	Ez = 'Ez'
+	Hx = 'Hx'
+	Hy = 'Hy'
+	Hz = 'Hz'
+
+	@staticmethod
+	def to_name(v: typ.Self) -> str:
+		"""Convert the enum value to a human-friendly name.
+
+		Notes:
+			Used to print names in `EnumProperty`s based on this enum.
+
+		Returns:
+			A human-friendly name corresponding to the enum value.
+		"""
+		SFP = SimFieldPols
+		return {
+			SFP.Ex: 'Ex',
+			SFP.Ey: 'Ey',
+			SFP.Ez: 'Ez',
+			SFP.Hx: 'Hx',
+			SFP.Hy: 'Hy',
+			SFP.Hz: 'Hz',
+		}[v]
+
+	@staticmethod
+	def to_icon(_: typ.Self) -> str:
+		"""Convert the enum value to a Blender icon.
+
+		Notes:
+			Used to print icons in `EnumProperty`s based on this enum.
+
+		Returns:
+			A human-friendly name corresponding to the enum value.
+		"""
+		return ''
+
+
 ####################
 # - Boundary Condition Type
 ####################

src/blender_maxwell/node_trees/maxwell_sim_nodes/managed_objs/base.py

@@ -25,14 +25,28 @@ log = logger.get(__name__)
 
 
 class ManagedObj(abc.ABC):
+	"""A weak name-based reference to some kind of object external to this software.
+
+	While the object doesn't have to come from Blender's `bpy.types`, that is admittedly the driving motivation for this class: To encapsulate access to the powerful visual tools granted by Blender's 3D viewport, image editor, and UI.
+	Through extensive testing, the functionality of an implicitly-cached, semi-strictly immediate-mode interface, demanding only a weakly-referenced name as persistance, has emerged (with all of the associated tradeoffs).
+
+	While not suited to all use cases, the `ManagedObj` paradigm is perfect for many situations where a node needs to "loosely own" something external and non-trivial.
+	Intriguingly, the precise definition of "loose" has grown to vary greatly between subclasses, as it ends of demonstrating itself to be a matter of taste more than determinism.
+
+	This abstract base class serves to provide a few of the most basic of commonly-available - especially the `dump_as_msgspec`/`parse_as_msgspec` methods that allow it to be persisted using `blender_maxwell.utils.serialize`.
+
+	Parameters:
+		managed_obj_type: Enum identifier indicating which of the `ct.ManagedObjType` the instance should declare itself as.
+	"""
+
 	managed_obj_type: ct.ManagedObjType
 
 	@abc.abstractmethod
-	def __init__(
+	def __init__(self, name: ct.ManagedObjName, prev_name: str | None = None):
-		self,
+		"""Initializes the managed object with a unique name.
-		name: ct.ManagedObjName,
+
-	):
+		Use `prev_name` to indicate that the managed object will initially be avaiable under `prev_name`, but that it should be renamed to `name`.
-		"""Initializes the managed object with a unique name."""
+		"""
 
 	####################
 	# - Properties
@@ -60,7 +74,7 @@ class ManagedObj(abc.ABC):
 
 	@abc.abstractmethod
 	def hide_preview(self) -> None:
-		"""Select the managed object in Blender, if such an operation makes sense."""
+		"""Hide any active preview of the managed object, if it exists, and if such an operation makes sense."""
 
 	####################
 	# - Serialization

src/blender_maxwell/node_trees/maxwell_sim_nodes/managed_objs/managed_bl_mesh.py

@@ -45,82 +45,57 @@ class ManagedBLMesh(base.ManagedObj):
 
 	@name.setter
 	def name(self, value: str) -> None:
-		log.info(
+		log.debug(
 			'Changing BLMesh w/Name "%s" to Name "%s"', self._bl_object_name, value
 		)
 
-		if self._bl_object_name == value:
+		existing_bl_object = bpy.data.objects.get(self.name)
-			## TODO: This is a workaround.
-			## Really, we can't tell if a name is valid by searching objects.
-			## Since, after all, other managedobjs may have taken a name..
-			## ...but not yet made an object that has it.
-			return
 
-		if (bl_object := bpy.data.objects.get(value)) is None:
+		# No Existing Object: Set Value to Name
-			log.info(
+		if existing_bl_object is None:
-				'Desired BLMesh Name "%s" Not Taken',
-				value,
-			)
-
-			if self._bl_object_name is None:
-				log.info(
-					'Set New BLMesh Name to "%s"',
-					value,
-				)
-			elif (bl_object := bpy.data.objects.get(self._bl_object_name)) is not None:
-				log.info(
-					'Changed BLMesh Name to "%s"',
-					value,
-				)
-				bl_object.name = value
-			else:
-				msg = f'ManagedBLMesh with name "{self._bl_object_name}" was deleted'
-				raise RuntimeError(msg)
-
-			# Set Internal Name
 			self._bl_object_name = value
+
+		# Existing Object: Rename to New Name
 		else:
-			log.info(
+			existing_bl_object.name = value
-				'Desired BLMesh Name "%s" is Taken. Using Blender Rename',
+			self._bl_object_name = value
-				value,
-			)
 
-			# Set Name Anyway, but Respect Blender's Renaming
+			# Check: Blender Rename -> Synchronization Error
-			## When a name already exists, Blender adds .### to prevent overlap.
+			## -> We can't do much else than report to the user & free().
-			## `set_name` is allowed to change the name; nodes account for this.
+			if existing_bl_object.name != self._bl_object_name:
-			bl_object.name = value
+				log.critical(
-			self._bl_object_name = bl_object.name
+					'BLMesh: Failed to set name of %s to %s, as %s already exists.'
-
-			log.info(
-				'Changed BLMesh Name to "%s"',
-				bl_object.name,
 				)
+				self._bl_object_name = existing_bl_object.name
+				self.free()
 
 	####################
 	# - Allocation
 	####################
-	def __init__(self, name: str):
+	def __init__(self, name: str, prev_name: str | None = None):
+		if prev_name is not None:
+			self._bl_object_name = prev_name
+		else:
+			self._bl_object_name = name
+
 		self.name = name
 
 	####################
 	# - Deallocation
 	####################
 	def free(self):
-		if (bl_object := bpy.data.objects.get(self.name)) is None:
+		bl_object = bpy.data.objects.get(self.name)
+		if bl_object is None:
 			return
 
-		# Delete the Underlying Datablock
+		# Delete the Mesh Datablock
-		## This automatically deletes the object too
+		## -> This automatically deletes the object too
-		log.info('Removing "%s" BLMesh', bl_object.type)
+		log.info('BLMesh: Freeing "%s"', self.name)
 		bpy.data.meshes.remove(bl_object.data)
 
 	####################
 	# - Methods
 	####################
-	@property
-	def exists(self) -> bool:
-		return bpy.data.objects.get(self.name) is not None
-
 	def show_preview(self) -> None:
 		"""Moves the managed Blender object to the preview collection.
 
@@ -128,7 +103,7 @@ class ManagedBLMesh(base.ManagedObj):
 		"""
 		bl_object = bpy.data.objects.get(self.name)
 		if bl_object is None:
-			log.info('Created previewable ManagedBLMesh "%s"', bl_object.name)
+			log.info('%s (ManagedBLMesh): Created BLObject for Preview', bl_object.name)
 			bl_object = self.bl_object()
 
 		if bl_object.name not in preview_collection().objects:
@@ -136,24 +111,19 @@ class ManagedBLMesh(base.ManagedObj):
 			preview_collection().objects.link(bl_object)
 
 	def hide_preview(self) -> None:
-		"""Removes the managed Blender object from the preview collection.
+		"""Hide any active preview of the managed object, if it exists, and if such an operation makes sense."""
-
-		If it's already removed, do nothing.
-		"""
 		bl_object = bpy.data.objects.get(self.name)
 		if bl_object is not None and bl_object.name in preview_collection().objects:
 			log.info('Removing "%s" from Preview Collection', bl_object.name)
 			preview_collection().objects.unlink(bl_object)
 
 	def bl_select(self) -> None:
-		"""Selects the managed Blender object, causing it to be ex. outlined in the 3D viewport."""
+		"""Select the managed object in Blender, if it exists, and if such an operation makes sense."""
-		if (bl_object := bpy.data.objects.get(self.name)) is not None:
+		bl_object = bpy.data.objects.get(self.name)
+		if bl_object is not None:
 			bpy.ops.object.select_all(action='DESELECT')
 			bl_object.select_set(True)
 
-		msg = 'Managed BLMesh does not exist'
-		raise ValueError(msg)
-
 	####################
 	# - BLMesh Management
 	####################

src/blender_maxwell/node_trees/maxwell_sim_nodes/managed_objs/managed_bl_modifier.py

@@ -26,6 +26,7 @@ from blender_maxwell.utils import logger
 from .. import bl_socket_map
 from .. import contracts as ct
 from . import base
+from .managed_bl_mesh import ManagedBLMesh
 
 log = logger.get(__name__)
 
@@ -71,7 +72,7 @@ def read_modifier(bl_modifier: bpy.types.Modifier) -> ModifierAttrs:
 		return {
 			'node_group': bl_modifier.node_group,
 		}
-	elif bl_modifier.type == 'ARRAY':
+	if bl_modifier.type == 'ARRAY':
 		raise NotImplementedError
 
 	raise NotImplementedError
@@ -162,6 +163,7 @@ def write_modifier(
 class ManagedBLModifier(base.ManagedObj):
 	managed_obj_type = ct.ManagedObjType.ManagedBLModifier
 	_modifier_name: str | None = None
+	twin_bl_mesh: ManagedBLMesh | None = None
 
 	####################
 	# - BL Object Name
@@ -172,94 +174,117 @@ class ManagedBLModifier(base.ManagedObj):
 
 	@name.setter
 	def name(self, value: str) -> None:
-		## TODO: Handle name conflict within same BLObject
+		log.debug('Changing BLModifier w/Name "%s" to Name "%s"', self.name, value)
-		log.info(
+
-			'Changing BLModifier w/Name "%s" to Name "%s"', self._modifier_name, value
+		twin_bl_object = bpy.data.objects.get(self.twin_bl_mesh.name)
-		)
+
+		# No Existing Twin BLObject
+		## -> Since no modifier-holding object exists, we're all set.
+		if twin_bl_object is None:
+			self._modifier_name = value
+
+		# Existing Twin BLObject
+		else:
+			# No Existing Modifier: Set Value to Name
+			## -> We'll rename the bl_object; otherwise we're set.
+			bl_modifier = twin_bl_object.modifiers.get(self.name)
+			if bl_modifier is None:
+				self.twin_bl_mesh.name = value
+				self._modifier_name = value
+
+			# Existing Modifier: Rename to New Name
+			## -> We'll rename the bl_modifier, then the bl_object.
+			else:
+				bl_modifier.name = value
+				self.twin_bl_mesh.name = value
 				self._modifier_name = value
 
 	####################
 	# - Allocation
 	####################
-	def __init__(self, name: str):
+	def __init__(self, name: str, prev_name: str | None = None):
+		self.twin_bl_mesh = ManagedBLMesh(name, prev_name=prev_name)
+		if prev_name is not None:
+			self._modifier_name = prev_name
+		else:
+			self._modifier_name = name
+
 		self.name = name
 
 	def bl_select(self) -> None:
-		pass
+		self.twin_bl_mesh.bl_select()
+
+	def show_preview(self) -> None:
+		self.twin_bl_mesh.show_preview()
 
 	def hide_preview(self) -> None:
-		pass
+		self.twin_bl_mesh.hide_preview()
 
 	####################
 	# - Deallocation
 	####################
 	def free(self):
-		"""Not needed - when the object is removed, its modifiers are also removed."""
+		log.info('BLModifier: Freeing "%s" w/Twin BLObject of same name', self.name)
-
+		self.twin_bl_mesh.free()
-	def free_from_bl_object(
-		self,
-		bl_object: bpy.types.Object,
-	) -> None:
-		"""Remove the managed BL modifier from the passed Blender object.
-
-		Parameters:
-			bl_object: The Blender object to remove the modifier from.
-		"""
-		if (bl_modifier := bl_object.modifiers.get(self.name)) is not None:
-			log.info(
-				'Removing (recreating) BLModifier "%s" on BLObject "%s" (existing modifier_type is "%s")',
-				bl_modifier.name,
-				bl_object.name,
-				bl_modifier.type,
-			)
-			bl_modifier = bl_object.modifiers.remove(bl_modifier)
-		else:
-			msg = f'Tried to free bl_modifier "{self.name}", but bl_object "{bl_object.name}" has no modifier of that name'
-			raise ValueError(msg)
 
 	####################
 	# - Modifiers
 	####################
 	def bl_modifier(
 		self,
-		bl_object: bpy.types.Object,
 		modifier_type: ct.BLModifierType,
 		modifier_attrs: ModifierAttrs,
+		location: tuple[float, float, float] = (0, 0, 0),
 	):
 		"""Creates a new modifier for the current `bl_object`.
 
 		- Modifier Type Names: <https://docs.blender.org/api/current/bpy_types_enum_items/object_modifier_type_items.html#rna-enum-object-modifier-type-items>
 		"""
-		# Remove Mismatching Modifier
+		# Retrieve Twin BLObject
+		twin_bl_object = self.twin_bl_mesh.bl_object(location=location)
+		if twin_bl_object is None:
+			msg = f'BLModifier: No BLObject twin "{self.name}" exists to attach a modifier to.'
+			raise ValueError(msg)
+
+		bl_modifier = twin_bl_object.modifiers.get(self.name)
+
+		# Existing Modifier: Maybe Remove
 		modifier_was_removed = False
-		if (
+		if bl_modifier is not None and bl_modifier.type != modifier_type:
-			bl_modifier := bl_object.modifiers.get(self.name)
-		) and bl_modifier.type != modifier_type:
 			log.info(
-				'Removing (recreating) BLModifier "%s" on BLObject "%s" (existing modifier_type is "%s", but "%s" is requested)',
+				'BLModifier: Clearing BLModifier "%s" from BLObject "%s"',
-				bl_modifier.name,
+				self.name,
-				bl_object.name,
+				twin_bl_object.name,
-				bl_modifier.type,
-				modifier_type,
 			)
-			self.free_from_bl_object(bl_object)
+			twin_bl_object.modifiers.remove(bl_modifier)
 			modifier_was_removed = True
 
-		# Create Modifier
+		# No/Removed Modifier: Create
 		if bl_modifier is None or modifier_was_removed:
 			log.info(
-				'Creating BLModifier "%s" on BLObject "%s" with modifier_type "%s"',
+				'BLModifier: (Re)Creating BLModifier "%s" on BLObject "%s" (type=%s)',
 				self.name,
-				bl_object.name,
+				twin_bl_object.name,
 				modifier_type,
 			)
-			bl_modifier = bl_object.modifiers.new(
+			bl_modifier = twin_bl_object.modifiers.new(
 				name=self.name,
 				type=modifier_type,
 			)
 
+		# Write Modifier Attrs
+		## -> For GeoNodes modifiers, this is the critical component.
+		## -> From 'write_modifier', we only need to know if something changed.
+		## -> If so, we make sure to update the object data.
 		modifier_altered = write_modifier(bl_modifier, modifier_attrs)
 		if modifier_altered:
-			bl_object.data.update()
+			twin_bl_object.data.update()
 
 		return bl_modifier
+
+	####################
+	# - Mesh Data
+	####################
+	@property
+	def mesh_as_arrays(self) -> dict:
+		return self.twin_bl_mesh.mesh_as_arrays

src/blender_maxwell/node_trees/maxwell_sim_nodes/nodes/base.py

@@ -131,27 +131,10 @@ class MaxwellSimNode(bpy.types.Node, bl_instance.BLInstance):
 			for i, (preset_name, preset_def) in enumerate(cls.presets.items())
 		]
 
-	####################
+	# Managed Objects
-	# - Managed Objects
+	managed_objs: dict[str, _managed_objs.ManagedObj] = bl_cache.BLField(
-	####################
+		{}, use_prop_update=False
-	@bl_cache.cached_bl_property(depends_on={'sim_node_name'})
+	)
-	def managed_objs(self) -> dict[str, _managed_objs.ManagedObj]:
-		"""Access the constructed managed objects defined in `self.managed_obj_types`.
-
-		Managed objects are special in that they **don't keep any non-reproducible state**.
-		In fact, all managed object state can generally be derived entirely from the managed object's `name` attribute.
-		As a result, **consistency in namespacing is of the utmost importance**, if reproducibility of managed objects is to be guaranteed.
-
-		This name must be in sync with the name of the managed "thing", which is where this computed property comes in.
-		The node's half of the responsibility is to push a new name whenever `self.sim_node_name` changes.
-		"""
-		if self.managed_obj_types:
-			return {
-				mobj_name: mobj_type(self.sim_node_name)
-				for mobj_name, mobj_type in self.managed_obj_types.items()
-			}
-
-		return {}
 
 	####################
 	# - Class Methods
@@ -221,25 +204,30 @@ class MaxwellSimNode(bpy.types.Node, bl_instance.BLInstance):
 	####################
 	@events.on_value_changed(
 		prop_name='sim_node_name',
-		props={'sim_node_name', 'managed_objs'},
+		props={'sim_node_name', 'managed_objs', 'managed_obj_types'},
 		stop_propagation=True,
 	)
 	def _on_sim_node_name_changed(self, props):
-		log.info(
+		log.debug(
 			'Changed Sim Node Name of a "%s" to "%s" (self=%s)',
 			self.bl_idname,
 			props['sim_node_name'],
 			str(self),
 		)
 
-		# Set Name of Managed Objects
+		# (Re)Construct Managed Objects
-		for mobj in props['managed_objs'].values():
+		## -> Due to 'prev_name', the new MObjs will be renamed on construction
-			mobj.name = props['sim_node_name']
+		self.managed_objs = {
-
+			mobj_name: mobj_type(
-		## Invalidate Cache
+				self.sim_node_name,
-		## -> Persistance doesn't happen if we simply mutate.
+				prev_name=(
-		## -> This ensures that the name change is picked up.
+					props['managed_objs'][mobj_name].name
-		self.managed_objs = bl_cache.Signal.InvalidateCache
+					if mobj_name in props['managed_objs']
+					else None
+				),
+			)
+			for mobj_name, mobj_type in props['managed_obj_types'].items()
+		}
 
 	@events.on_value_changed(prop_name='active_socket_set')
 	def _on_socket_set_changed(self):
@@ -1027,12 +1015,14 @@ class MaxwellSimNode(bpy.types.Node, bl_instance.BLInstance):
 				bl_socket.reset_instance_id()
 
 		# Generate New Sim Node Name
-		## Blender will automatically add .001 so that `self.name` is unique.
+		## -> Blender will adds .00# so that `self.name` is unique.
+		## -> We can shamelessly piggyback on this for unique managed objs.
+		## -> ...But to avoid stealing the old node's mobjs, we first rename.
 		self.sim_node_name = self.name
 
 		# Event Methods
-		## Run any 'DataChanged' methods with 'run_on_init' set.
+		## -> Re-run any 'DataChanged' methods with 'run_on_init' set.
-		## -> Copying a node _arguably_ re-initializes the new node.
+		## -> Copying a node ~ re-initializing the new node.
 		for event_method in [
 			event_method
 			for event_method in self.event_methods_by_event[ct.FlowEvent.DataChanged]

src/blender_maxwell/node_trees/maxwell_sim_nodes/nodes/bounds/bound_cond_nodes/bloch_bound_cond.py

@@ -132,7 +132,7 @@ class BlochBoundCondNode(base.MaxwellSimNode):
 	####################
 	# - Properties
 	####################
-	valid_sim_axis: ct.SimSpaceAxis = bl_cache.BLField(ct.SimSpaceAxis.X, prop_ui=True)
+	valid_sim_axis: ct.SimSpaceAxis = bl_cache.BLField(ct.SimSpaceAxis.X)
 
 	####################
 	# - UI

src/blender_maxwell/node_trees/maxwell_sim_nodes/nodes/mediums/library_medium.py

@@ -24,13 +24,15 @@ import tidy3d as td
 from tidy3d.material_library.material_library import MaterialItem as Tidy3DMediumItem
 from tidy3d.material_library.material_library import VariantItem as Tidy3DMediumVariant
 
-from blender_maxwell.utils import bl_cache, sci_constants
+from blender_maxwell.utils import bl_cache, logger, sci_constants
 from blender_maxwell.utils import extra_sympy_units as spux
 
 from ... import contracts as ct
 from ... import managed_objs, sockets
 from .. import base, events
 
+log = logger.get(__name__)
+
 _mat_lib_iter = iter(td.material_library)
 _mat_key = ''
 
@@ -131,7 +133,8 @@ class LibraryMediumNode(base.MaxwellSimNode):
 	####################
 	vendored_medium: VendoredMedium = bl_cache.BLField(VendoredMedium.Au)
 	variant_name: enum.StrEnum = bl_cache.BLField(
-		enum_cb=lambda self, _: self.search_variants()
+		enum_cb=lambda self, _: self.search_variants(),
+		cb_depends_on={'vendored_medium'},
 	)
 
 	def search_variants(self) -> list[ct.BLEnumElement]:
@@ -141,7 +144,7 @@ class LibraryMediumNode(base.MaxwellSimNode):
 	####################
 	# - Computed
 	####################
-	@bl_cache.cached_bl_property(depends_on={'vendored_medium', 'variant_name'})
+	@bl_cache.cached_bl_property(depends_on={'variant_name'})
 	def variant(self) -> Tidy3DMediumVariant:
 		"""Deduce the actual medium variant from `self.vendored_medium` and `self.variant_name`."""
 		return self.vendored_medium.medium_variants[self.variant_name]
@@ -239,21 +242,6 @@ class LibraryMediumNode(base.MaxwellSimNode):
 		if self.data_url is not None:
 			box.operator('wm.url_open', text='Link to Data').url = self.data_url
 
-	####################
-	# - Events
-	####################
-	@events.on_value_changed(
-		prop_name={'vendored_medium', 'variant_name'},
-		run_on_init=True,
-		props={'vendored_medium'},
-	)
-	def on_medium_changed(self, props):
-		if self.variant_name not in props['vendored_medium'].medium_variants:
-			self.variant_name = bl_cache.Signal.ResetEnumItems
-
-		self.ui_freq_range = bl_cache.Signal.InvalidateCache
-		self.ui_wl_range = bl_cache.Signal.InvalidateCache
-
 	####################
 	# - Output
 	####################
@@ -264,13 +252,6 @@ class LibraryMediumNode(base.MaxwellSimNode):
 	def compute_medium(self, props) -> sp.Expr:
 		return props['medium']
 
-	@events.computes_output_socket(
-		'Valid Freqs',
-		props={'freq_range'},
-	)
-	def compute_valid_freqs(self, props) -> sp.Expr:
-		return props['freq_range']
-
 	@events.computes_output_socket(
 		'Valid Freqs',
 		kind=ct.FlowKind.LazyArrayRange,
@@ -285,13 +266,6 @@ class LibraryMediumNode(base.MaxwellSimNode):
 			unit=spux.THz,
 		)
 
-	@events.computes_output_socket(
-		'Valid WLs',
-		props={'wl_range'},
-	)
-	def compute_valid_wls(self, props) -> sp.Expr:
-		return props['wl_range']
-
 	@events.computes_output_socket(
 		'Valid WLs',
 		kind=ct.FlowKind.LazyArrayRange,
@@ -320,7 +294,7 @@ class LibraryMediumNode(base.MaxwellSimNode):
 		props,
 	):
 		managed_objs['plot'].mpl_plot_to_image(
-			lambda ax: self.medium.plot(props['medium'].frequency_range, ax=ax),
+			lambda ax: props['medium'].plot(props['medium'].frequency_range, ax=ax),
 			bl_select=True,
 		)
 		## TODO: Plot based on Wl, not freq.

src/blender_maxwell/node_trees/maxwell_sim_nodes/nodes/monitors/__init__.py

@@ -14,20 +14,19 @@
 # You should have received a copy of the GNU Affero General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
-from . import eh_field_monitor, field_power_flux_monitor
+from . import eh_field_monitor, field_power_flux_monitor, permittivity_monitor
 
-# from . import epsilon_tensor_monitor
 # from . import diffraction_monitor
 
 BL_REGISTER = [
 	*eh_field_monitor.BL_REGISTER,
 	*field_power_flux_monitor.BL_REGISTER,
-	# *epsilon_tensor_monitor.BL_REGISTER,
+	*permittivity_monitor.BL_REGISTER,
 	# *diffraction_monitor.BL_REGISTER,
 ]
 BL_NODES = {
 	**eh_field_monitor.BL_NODES,
 	**field_power_flux_monitor.BL_NODES,
-	# **epsilon_tensor_monitor.BL_NODES,
+	**permittivity_monitor.BL_NODES,
 	# **diffraction_monitor.BL_NODES,
 }

src/blender_maxwell/node_trees/maxwell_sim_nodes/nodes/monitors/eh_field_monitor.py

@@ -16,13 +16,14 @@
 
 import typing as typ
 
+import bpy
 import sympy as sp
 import sympy.physics.units as spu
 import tidy3d as td
 
 from blender_maxwell.assets.geonodes import GeoNodes, import_geonodes
+from blender_maxwell.utils import bl_cache, logger
 from blender_maxwell.utils import extra_sympy_units as spux
-from blender_maxwell.utils import logger
 
 from ... import contracts as ct
 from ... import managed_objs, sockets
@@ -50,11 +51,13 @@ class EHFieldMonitorNode(base.MaxwellSimNode):
 			size=spux.NumberSize1D.Vec3,
 			physical_type=spux.PhysicalType.Length,
 			default_value=sp.Matrix([1, 1, 1]),
+			abs_min=0,
 		),
-		'Spatial Subdivs': sockets.ExprSocketDef(
+		'Stride': sockets.ExprSocketDef(
 			size=spux.NumberSize1D.Vec3,
 			mathtype=spux.MathType.Integer,
 			default_value=sp.Matrix([10, 10, 10]),
+			abs_min=0,
 		),
 	}
 	input_socket_sets: typ.ClassVar = {
@@ -69,15 +72,15 @@ class EHFieldMonitorNode(base.MaxwellSimNode):
 			),
 		},
 		'Time Domain': {
-			'Time Range': sockets.ExprSocketDef(
+			't Range': sockets.ExprSocketDef(
 				active_kind=ct.FlowKind.LazyArrayRange,
 				physical_type=spux.PhysicalType.Time,
 				default_unit=spu.picosecond,
 				default_min=0,
 				default_max=10,
-				default_steps=2,
+				default_steps=0,
 			),
-			'Temporal Subdivs': sockets.ExprSocketDef(
+			't Stride': sockets.ExprSocketDef(
 				mathtype=spux.MathType.Integer,
 				default_value=100,
 			),
@@ -89,20 +92,30 @@ class EHFieldMonitorNode(base.MaxwellSimNode):
 	}
 
 	managed_obj_types: typ.ClassVar = {
-		'mesh': managed_objs.ManagedBLMesh,
 		'modifier': managed_objs.ManagedBLModifier,
 	}
 
+	####################
+	# - Properties
+	####################
+	fields: set[ct.SimFieldPols] = bl_cache.BLField(set(ct.SimFieldPols))
+
+	####################
+	# - UI
+	####################
+	def draw_props(self, _: bpy.types.Context, layout: bpy.types.UILayout) -> None:
+		layout.prop(self, self.blfields['fields'], expand=True)
+
 	####################
 	# - Output
 	####################
 	@events.computes_output_socket(
 		'Freq Monitor',
-		props={'sim_node_name'},
+		props={'sim_node_name', 'fields'},
 		input_sockets={
 			'Center',
 			'Size',
-			'Spatial Subdivs',
+			'Stride',
 			'Freqs',
 		},
 		input_socket_kinds={
@@ -131,28 +144,29 @@ class EHFieldMonitorNode(base.MaxwellSimNode):
 			center=input_sockets['Center'],
 			size=input_sockets['Size'],
 			name=props['sim_node_name'],
-			interval_space=tuple(input_sockets['Spatial Subdivs']),
+			interval_space=tuple(input_sockets['Stride']),
 			freqs=input_sockets['Freqs'].realize().values,
+			fields=props['fields'],
 		)
 
 	@events.computes_output_socket(
 		'Time Monitor',
-		props={'sim_node_name'},
+		props={'sim_node_name', 'fields'},
 		input_sockets={
 			'Center',
 			'Size',
-			'Spatial Subdivs',
+			'Stride',
-			'Time Range',
+			't Range',
-			'Temporal Subdivs',
+			't Stride',
 		},
 		input_socket_kinds={
-			'Time Range': ct.FlowKind.LazyArrayRange,
+			't Range': ct.FlowKind.LazyArrayRange,
 		},
 		unit_systems={'Tidy3DUnits': ct.UNITS_TIDY3D},
 		scale_input_sockets={
 			'Center': 'Tidy3DUnits',
 			'Size': 'Tidy3DUnits',
-			'Time Range': 'Tidy3DUnits',
+			't Range': 'Tidy3DUnits',
 		},
 	)
 	def compute_time_monitor(
@@ -171,10 +185,11 @@ class EHFieldMonitorNode(base.MaxwellSimNode):
 			center=input_sockets['Center'],
 			size=input_sockets['Size'],
 			name=props['sim_node_name'],
-			interval_space=tuple(input_sockets['Spatial Subdivs']),
+			interval_space=tuple(input_sockets['Stride']),
-			start=input_sockets['Time Range'].realize_start(),
+			start=input_sockets['t Range'].realize_start(),
-			stop=input_sockets['Time Range'].realize_stop(),
+			stop=input_sockets['t Range'].realize_stop(),
-			interval=input_sockets['Temporal Subdivs'],
+			interval=input_sockets['t Stride'],
+			fields=props['fields'],
 		)
 
 	####################
@@ -184,26 +199,21 @@ class EHFieldMonitorNode(base.MaxwellSimNode):
 		# Trigger
 		prop_name='preview_active',
 		# Loaded
-		managed_objs={'mesh'},
+		managed_objs={'modifier'},
 		props={'preview_active'},
-		input_sockets={'Center', 'Size'},
 	)
-	def on_preview_changed(self, managed_objs, props, input_sockets):
+	def on_preview_changed(self, managed_objs, props):
-		"""Enables/disables previewing of the GeoNodes-driven mesh, regardless of whether a particular GeoNodes tree is chosen."""
-		mesh = managed_objs['mesh']
-
-		# Push Preview State to Managed Mesh
 		if props['preview_active']:
-			mesh.show_preview()
+			managed_objs['modifier'].show_preview()
 		else:
-			mesh.hide_preview()
+			managed_objs['modifier'].hide_preview()
 
 	@events.on_value_changed(
 		# Trigger
 		socket_name={'Center', 'Size'},
 		run_on_init=True,
 		# Loaded
-		managed_objs={'mesh', 'modifier'},
+		managed_objs={'modifier'},
 		input_sockets={'Center', 'Size'},
 		unit_systems={'BlenderUnits': ct.UNITS_BLENDER},
 		scale_input_sockets={
@@ -218,7 +228,6 @@ class EHFieldMonitorNode(base.MaxwellSimNode):
 	):
 		# Push Input Values to GeoNodes Modifier
 		managed_objs['modifier'].bl_modifier(
-			managed_objs['mesh'].bl_object(location=input_sockets['Center']),
 			'NODES',
 			{
 				'node_group': import_geonodes(GeoNodes.MonitorEHField),
@@ -227,6 +236,7 @@ class EHFieldMonitorNode(base.MaxwellSimNode):
 					'Size': input_sockets['Size'],
 				},
 			},
+			location=input_sockets['Center'],
 		)
 
 

src/blender_maxwell/node_trees/maxwell_sim_nodes/nodes/monitors/epsilon_tensor_monitor.py

@@ -1,21 +0,0 @@
-# blender_maxwell
-# Copyright (C) 2024 blender_maxwell Project Contributors
-#
-# This program is free software: you can redistribute it and/or modify
-# it under the terms of the GNU Affero General Public License as published by
-# the Free Software Foundation, either version 3 of the License, or
-# (at your option) any later version.
-#
-# This program is distributed in the hope that it will be useful,
-# but WITHOUT ANY WARRANTY; without even the implied warranty of
-# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-# GNU Affero General Public License for more details.
-#
-# You should have received a copy of the GNU Affero General Public License
-# along with this program.  If not, see <http://www.gnu.org/licenses/>.
-
-####################
-# - Blender Registration
-####################
-BL_REGISTER = []
-BL_NODES = {}

src/blender_maxwell/node_trees/maxwell_sim_nodes/nodes/monitors/field_power_flux_monitor.py

@@ -16,13 +16,14 @@
 
 import typing as typ
 
+import bpy
 import sympy as sp
 import sympy.physics.units as spu
 import tidy3d as td
 
 from blender_maxwell.assets.geonodes import GeoNodes, import_geonodes
+from blender_maxwell.utils import bl_cache, logger
 from blender_maxwell.utils import extra_sympy_units as spux
-from blender_maxwell.utils import logger
 
 from ... import contracts as ct
 from ... import managed_objs, sockets
@@ -32,6 +33,8 @@ log = logger.get(__name__)
 
 
 class PowerFluxMonitorNode(base.MaxwellSimNode):
+	"""Node providing for the monitoring of electromagnetic field flux a given planar region or volume, in either the frequency or the time domain."""
+
 	node_type = ct.NodeType.PowerFluxMonitor
 	bl_label = 'Power Flux Monitor'
 	use_sim_node_name = True
@@ -48,13 +51,14 @@ class PowerFluxMonitorNode(base.MaxwellSimNode):
 			size=spux.NumberSize1D.Vec3,
 			physical_type=spux.PhysicalType.Length,
 			default_value=sp.Matrix([1, 1, 1]),
+			abs_min=0,
 		),
-		'Samples/Space': sockets.ExprSocketDef(
+		'Stride': sockets.ExprSocketDef(
 			size=spux.NumberSize1D.Vec3,
 			mathtype=spux.MathType.Integer,
 			default_value=sp.Matrix([10, 10, 10]),
+			abs_min=0,
 		),
-		'Direction': sockets.BoolSocketDef(),
 	}
 	input_socket_sets: typ.ClassVar = {
 		'Freq Domain': {
@@ -68,7 +72,7 @@ class PowerFluxMonitorNode(base.MaxwellSimNode):
 			),
 		},
 		'Time Domain': {
-			'Time Range': sockets.ExprSocketDef(
+			't Range': sockets.ExprSocketDef(
 				active_kind=ct.FlowKind.LazyArrayRange,
 				physical_type=spux.PhysicalType.Time,
 				default_unit=spu.picosecond,
@@ -76,7 +80,7 @@ class PowerFluxMonitorNode(base.MaxwellSimNode):
 				default_max=10,
 				default_steps=2,
 			),
-			'Samples/Time': sockets.ExprSocketDef(
+			't Stride': sockets.ExprSocketDef(
 				mathtype=spux.MathType.Integer,
 				default_value=100,
 			),
@@ -92,18 +96,45 @@ class PowerFluxMonitorNode(base.MaxwellSimNode):
 		'modifier': managed_objs.ManagedBLModifier,
 	}
 
+	####################
+	# - Properties
+	####################
+	direction_2d: ct.SimAxisDir = bl_cache.BLField(ct.SimAxisDir.Plus)
+	include_3d: set[ct.SimSpaceAxis] = bl_cache.BLField(set(ct.SimSpaceAxis))
+	include_3d_x: set[ct.SimAxisDir] = bl_cache.BLField(set(ct.SimAxisDir))
+	include_3d_y: set[ct.SimAxisDir] = bl_cache.BLField(set(ct.SimAxisDir))
+	include_3d_z: set[ct.SimAxisDir] = bl_cache.BLField(set(ct.SimAxisDir))
+
+	####################
+	# - UI
+	####################
+	def draw_props(self, _: bpy.types.Context, layout: bpy.types.UILayout) -> None:
+		# 2D Monitor
+		if 0 in self._compute_input('Size'):
+			layout.prop(self, self.blfields['direction_2d'], expand=True)
+
+		# 3D Monitor
+		else:
+			layout.prop(self, self.blfields['include_3d'], expand=True)
+			row = layout.row(align=False)
+			if ct.SimSpaceAxis.X in self.include_3d:
+				row.prop(self, self.blfields['include_3d_x'], expand=True)
+			if ct.SimSpaceAxis.Y in self.include_3d:
+				row.prop(self, self.blfields['include_3d_y'], expand=True)
+			if ct.SimSpaceAxis.Z in self.include_3d:
+				row.prop(self, self.blfields['include_3d_z'], expand=True)
+
 	####################
 	# - Event Methods: Computation
 	####################
 	@events.computes_output_socket(
 		'Freq Monitor',
-		props={'sim_node_name'},
+		props={'sim_node_name', 'direction_2d'},
 		input_sockets={
 			'Center',
 			'Size',
-			'Samples/Space',
+			'Stride',
 			'Freqs',
-			'Direction',
 		},
 		input_socket_kinds={
 			'Freqs': ct.FlowKind.LazyArrayRange,
@@ -133,7 +164,7 @@ class PowerFluxMonitorNode(base.MaxwellSimNode):
 			name=props['sim_node_name'],
 			interval_space=(1, 1, 1),
 			freqs=input_sockets['Freqs'].realize_array.values,
-			normal_dir='+' if input_sockets['Direction'] else '-',
+			normal_dir=props['direction_2d'].plus_or_minus,
 		)
 
 	####################
@@ -143,49 +174,42 @@ class PowerFluxMonitorNode(base.MaxwellSimNode):
 		# Trigger
 		prop_name='preview_active',
 		# Loaded
-		managed_objs={'mesh'},
+		managed_objs={'modifier'},
 		props={'preview_active'},
 	)
 	def on_preview_changed(self, managed_objs, props):
-		"""Enables/disables previewing of the GeoNodes-driven mesh, regardless of whether a particular GeoNodes tree is chosen."""
-		mesh = managed_objs['mesh']
-
-		# Push Preview State to Managed Mesh
 		if props['preview_active']:
-			mesh.show_preview()
+			managed_objs['modifier'].show_preview()
 		else:
-			mesh.hide_preview()
+			managed_objs['modifier'].hide_preview()
 
 	@events.on_value_changed(
 		# Trigger
-		socket_name={'Center', 'Size', 'Direction'},
+		socket_name={'Center', 'Size'},
+		prop_name={'direction_2d'},
 		run_on_init=True,
 		# Loaded
 		managed_objs={'mesh', 'modifier'},
-		input_sockets={'Center', 'Size', 'Direction'},
+		props={'direction_2d'},
+		input_sockets={'Center', 'Size'},
 		unit_systems={'BlenderUnits': ct.UNITS_BLENDER},
 		scale_input_sockets={
 			'Center': 'BlenderUnits',
 		},
 	)
-	def on_inputs_changed(
+	def on_inputs_changed(self, managed_objs, props, input_sockets, unit_systems):
-		self,
-		managed_objs: dict,
-		input_sockets: dict,
-		unit_systems: dict,
-	):
 		# Push Input Values to GeoNodes Modifier
 		managed_objs['modifier'].bl_modifier(
-			managed_objs['mesh'].bl_object(location=input_sockets['Center']),
 			'NODES',
 			{
 				'node_group': import_geonodes(GeoNodes.MonitorPowerFlux),
 				'unit_system': unit_systems['BlenderUnits'],
 				'inputs': {
 					'Size': input_sockets['Size'],
-					'Direction': input_sockets['Direction'],
+					'Direction': props['direction_2d'].true_or_false,
 				},
 			},
+			location=input_sockets['Center'],
 		)
 
 

src/blender_maxwell/node_trees/maxwell_sim_nodes/nodes/monitors/permittivity_monitor.py

@@ -0,0 +1,173 @@
+# blender_maxwell
+# Copyright (C) 2024 blender_maxwell Project Contributors
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Affero General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU Affero General Public License for more details.
+#
+# You should have received a copy of the GNU Affero General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+import typing as typ
+
+import sympy as sp
+import tidy3d as td
+
+from blender_maxwell.assets.geonodes import GeoNodes, import_geonodes
+from blender_maxwell.utils import extra_sympy_units as spux
+from blender_maxwell.utils import logger
+
+from ... import contracts as ct
+from ... import managed_objs, sockets
+from .. import base, events
+
+log = logger.get(__name__)
+
+
+class PermittivityMonitorNode(base.MaxwellSimNode):
+	"""Provides a bounded 1D/2D/3D recording region for the diagonal of the complex-valued permittivity tensor."""
+
+	node_type = ct.NodeType.PermittivityMonitor
+	bl_label = 'Permittivity Monitor'
+	use_sim_node_name = True
+
+	####################
+	# - Sockets
+	####################
+	input_sockets: typ.ClassVar = {
+		'Center': sockets.ExprSocketDef(
+			size=spux.NumberSize1D.Vec3,
+			physical_type=spux.PhysicalType.Length,
+		),
+		'Size': sockets.ExprSocketDef(
+			size=spux.NumberSize1D.Vec3,
+			physical_type=spux.PhysicalType.Length,
+			default_value=sp.Matrix([1, 1, 1]),
+			abs_min=0,
+		),
+		'Stride': sockets.ExprSocketDef(
+			size=spux.NumberSize1D.Vec3,
+			mathtype=spux.MathType.Integer,
+			default_value=sp.Matrix([10, 10, 10]),
+			abs_min=0,
+		),
+		'Freqs': sockets.ExprSocketDef(
+			active_kind=ct.FlowKind.LazyArrayRange,
+			physical_type=spux.PhysicalType.Freq,
+			default_unit=spux.THz,
+			default_min=374.7406,  ## 800nm
+			default_max=1498.962,  ## 200nm
+			default_steps=100,
+		),
+	}
+	output_sockets: typ.ClassVar = {
+		'Permittivity Monitor': sockets.MaxwellMonitorSocketDef()
+	}
+
+	managed_obj_types: typ.ClassVar = {
+		'modifier': managed_objs.ManagedBLModifier,
+	}
+
+	####################
+	# - Output
+	####################
+	@events.computes_output_socket(
+		'Permittivity Monitor',
+		props={'sim_node_name'},
+		input_sockets={
+			'Center',
+			'Size',
+			'Stride',
+			'Freqs',
+		},
+		input_socket_kinds={
+			'Freqs': ct.FlowKind.LazyArrayRange,
+		},
+		unit_systems={'Tidy3DUnits': ct.UNITS_TIDY3D},
+		scale_input_sockets={
+			'Center': 'Tidy3DUnits',
+			'Size': 'Tidy3DUnits',
+			'Freqs': 'Tidy3DUnits',
+		},
+	)
+	def compute_permittivity_monitor(
+		self,
+		input_sockets: dict,
+		props: dict,
+		unit_systems: dict,
+	) -> td.FieldMonitor:
+		log.info(
+			'Computing PermittivityMonitor (name="%s") with center="%s", size="%s"',
+			props['sim_node_name'],
+			input_sockets['Center'],
+			input_sockets['Size'],
+		)
+		return td.PermittivityMonitor(
+			center=input_sockets['Center'],
+			size=input_sockets['Size'],
+			name=props['sim_node_name'],
+			interval_space=tuple(input_sockets['Stride']),
+			freqs=input_sockets['Freqs'].realize().values,
+		)
+
+	####################
+	# - Preview
+	####################
+	@events.on_value_changed(
+		# Trigger
+		prop_name='preview_active',
+		# Loaded
+		managed_objs={'modifier'},
+		props={'preview_active'},
+	)
+	def on_preview_changed(self, managed_objs, props):
+		if props['preview_active']:
+			managed_objs['modifier'].show_preview()
+		else:
+			managed_objs['modifier'].hide_preview()
+
+	@events.on_value_changed(
+		# Trigger
+		socket_name={'Center', 'Size'},
+		run_on_init=True,
+		# Loaded
+		managed_objs={'modifier'},
+		input_sockets={'Center', 'Size'},
+		unit_systems={'BlenderUnits': ct.UNITS_BLENDER},
+		scale_input_sockets={
+			'Center': 'BlenderUnits',
+		},
+	)
+	def on_inputs_changed(
+		self,
+		managed_objs: dict,
+		input_sockets: dict,
+		unit_systems: dict,
+	):
+		# Push Input Values to GeoNodes Modifier
+		managed_objs['modifier'].bl_modifier(
+			'NODES',
+			{
+				'node_group': import_geonodes(GeoNodes.MonitorPermittivity),
+				'unit_system': unit_systems['BlenderUnits'],
+				'inputs': {
+					'Size': input_sockets['Size'],
+				},
+			},
+			location=input_sockets['Center'],
+		)
+
+
+####################
+# - Blender Registration
+####################
+BL_REGISTER = [
+	PermittivityMonitorNode,
+]
+BL_NODES = {ct.NodeType.PermittivityMonitor: (ct.NodeCategory.MAXWELLSIM_MONITORS)}

src/blender_maxwell/node_trees/maxwell_sim_nodes/sockets/basic/bool.py

@@ -16,6 +16,8 @@
 
 import bpy
 
+from blender_maxwell.utils import bl_cache, logger
+
 from ... import contracts as ct
 from .. import base
 
@@ -30,19 +32,13 @@ class BoolBLSocket(base.MaxwellSimSocket):
 	####################
 	# - Properties
 	####################
-	raw_value: bpy.props.BoolProperty(
+	raw_value: bool = bl_cache.BLField(False)
-		name='Boolean',
-		description='Represents a boolean value',
-		default=False,
-		update=(lambda self, context: self.on_prop_changed('raw_value', context)),
-	)
 
 	####################
 	# - Socket UI
 	####################
 	def draw_label_row(self, label_col_row: bpy.types.UILayout, text: str) -> None:
-		label_col_row.label(text=text)
+		label_col_row.prop(self, self.blfields['raw_value'], text=text, toggle=True)
-		label_col_row.prop(self, 'raw_value', text='')
 
 	####################
 	# - Computation of Default Value

src/blender_maxwell/node_trees/maxwell_sim_nodes/sockets/expr.py

@@ -22,7 +22,6 @@ import typing as typ
 import bpy
 import pydantic as pyd
 import sympy as sp
-import sympy.physics.units as spu
 
 from blender_maxwell.utils import bl_cache, logger
 from blender_maxwell.utils import extra_sympy_units as spux
@@ -126,7 +125,6 @@ class ExprBLSocket(base.MaxwellSimSocket):
 
 	active_unit: enum.StrEnum = bl_cache.BLField(
 		enum_cb=lambda self, _: self.search_valid_units(),
-		use_prop_update=False,
 		cb_depends_on={'physical_type'},
 	)
 

src/blender_maxwell/node_trees/maxwell_sim_nodes/sockets/maxwell/medium.py

@@ -19,11 +19,14 @@ import scipy as sc
 import sympy.physics.units as spu
 import tidy3d as td
 
+from blender_maxwell.utils import bl_cache, logger
 from blender_maxwell.utils import extra_sympy_units as spux
 
 from ... import contracts as ct
 from .. import base
 
+log = logger.get(__name__)
+
 VAC_SPEED_OF_LIGHT = sc.constants.speed_of_light * spu.meter / spu.second
 
 FIXED_WL = 500 * spu.nm
@@ -36,16 +39,7 @@ class MaxwellMediumBLSocket(base.MaxwellSimSocket):
 	####################
 	# - Properties
 	####################
-	rel_permittivity: bpy.props.FloatVectorProperty(
+	rel_permittivity: tuple[float, float] = bl_cache.BLField((1.0, 0.0), float_prec=2)
-		name='Relative Permittivity',
-		description='Represents a simple, complex permittivity',
-		size=2,
-		default=(1.0, 0.0),
-		precision=2,
-		update=(
-			lambda self, context: self.on_prop_changed('rel_permittivity', context)
-		),
-	)
 
 	####################
 	# - FlowKinds
@@ -83,7 +77,7 @@ class MaxwellMediumBLSocket(base.MaxwellSimSocket):
 		col.label(text='ϵ_r (ℂ)')
 
 		col = split.column(align=True)
-		col.prop(self, 'rel_permittivity', text='')
+		col.prop(self, self.blfields['rel_permittivity'], text='')
 
 
 ####################

src/blender_maxwell/utils/bl_cache/bl_prop_type.py

@@ -649,7 +649,8 @@ class BLPropType(enum.StrEnum):
 			case BPT.SingleEnum if isinstance(raw_value, str):
 				return obj_type(raw_value)
 			case BPT.SetEnum if isinstance(raw_value, set):
-				return {obj_type(v) for v in raw_value}
+				SubStrEnum = typ.get_args(obj_type)[0]
+				return {SubStrEnum(v) for v in raw_value}
 
 			## Dynamic Enums: Nothing to coerce to.
 			## -> The critical distinction is that dynamic enums can't be coerced beyond str.

src/blender_maxwell/utils/bl_cache/cached_bl_property.py

@@ -154,7 +154,6 @@ class CachedBLProperty:
 				if self.persist and not self.suppress_write.get(
 					bl_instance.instance_id
 				):
-					self.suppress_next_write(bl_instance)
 					self.bl_prop.write(bl_instance, self.getter_method(bl_instance))
 
 				else: