feat: first fully parameterized simulation

We also believe we've fixed the crash related to read-during-write of
certain properties, by altering `BLField`'s invalidation to only
invalidate the non-persistent cache when it isn't suppressed.
This has no effect on the non-persistent cache, which is invalidated
correctly anyway during the write() that suppression is defined for;
however, by not stripping it away while that write() is being
implemented by Blender, CPython's builtin atomic `dict` operations
(especially `.get()`) manage to provide the thread-safety that we seem
to have been missing.

We tested the race-condition by the usual "drive everything from one
parameter", and weren't able to trigger one. Here's to hoping.

We've also started to become large fans of the "`Value` from `Func`"
principle, which both allows `Value` to pick up on fully realized
symbols in preceding flows, while also guaranteeing that we're not
maintaining duplicate code-paths.
However, the cost of the organizational reduction is that it is admittedly
slower (in the interactive hot-loop) than we'd like - in large part due
to having to realize a `FuncFlow` every time. However, certain
optimizations have a lot of potential:
- Reducing extraneous invalidations of `.lazy_func` on the `ExprSocket`,
  though some cleverness with `.output_sym` is needed.
- Pure performance work on all `Flow` objects. Surprisingly, they seem
  to mean a lot.

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

@@ -624,7 +624,7 @@ class FuncFlow(pyd.BaseModel):
 			# Compose Unit-Converted FuncFlow
 			return self.compose_within(
 				enclosing_func=unit_convert_func,
-				supports_jax=True,
+				supports_jax=self.supports_jax,
 				enclosing_func_output=self.func_output.update(unit=None),
 			)
 

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

@@ -261,7 +261,7 @@ class ManagedBLImage(base.ManagedObj):
 		dpi: int | None = None,
 		bl_select: bool = False,
 	):
-		times = ['START', time.perf_counter()]
+		times = [time.perf_counter()]
 
 		# Compute Plot Dimensions
 		# aspect_ratio, _dpi, _width_inches, _height_inches, width_px, height_px = (

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

@@ -86,9 +86,8 @@ class EHFieldMonitorNode(base.MaxwellSimNode):
 			),
 		},
 	}
-	output_socket_sets: typ.ClassVar = {
-		'Freq Domain': {'Freq Monitor': sockets.MaxwellMonitorSocketDef()},
-		'Time Domain': {'Time Monitor': sockets.MaxwellMonitorSocketDef()},
+	output_sockets: typ.ClassVar = {
+		'Monitor': sockets.MaxwellMonitorSocketDef(active_kind=ct.FlowKind.Func),
 	}
 
 	managed_obj_types: typ.ClassVar = {
@@ -107,111 +106,190 @@ class EHFieldMonitorNode(base.MaxwellSimNode):
 		layout.prop(self, self.blfields['fields'], expand=True)
 
 	####################
-	# - Output
+	# - FlowKind.Value
 	####################
 	@events.computes_output_socket(
-		'Freq Monitor',
-		props={'sim_node_name', 'fields'},
+		'Monitor',
+		kind=ct.FlowKind.Value,
+		# Loaded
+		output_sockets={'Monitor'},
+		output_socket_kinds={'Monitor': {ct.FlowKind.Func, ct.FlowKind.Params}},
+	)
+	def compute_value(self, output_sockets) -> ct.ParamsFlow | ct.FlowSignal:
+		"""Compute the particular value of the simulation domain from strictly non-symbolic inputs."""
+		output_func = output_sockets['Monitor'][ct.FlowKind.Func]
+		output_params = output_sockets['Monitor'][ct.FlowKind.Params]
+
+		has_output_func = not ct.FlowSignal.check(output_func)
+		has_output_params = not ct.FlowSignal.check(output_params)
+
+		if has_output_func and has_output_params and not output_params.symbols:
+			return output_func.realize(output_params, disallow_jax=True)
+		return ct.FlowSignal.FlowPending
+
+	####################
+	# - FlowKind.Func
+	####################
+	@events.computes_output_socket(
+		'Monitor',
+		kind=ct.FlowKind.Func,
+		# Loaded
+		props={'active_socket_set', 'sim_node_name', 'fields'},
 		input_sockets={
 			'Center',
 			'Size',
 			'Stride',
 			'Freqs',
-		},
-		input_socket_kinds={
-			'Freqs': ct.FlowKind.Range,
-		},
-		unit_systems={'Tidy3DUnits': ct.UNITS_TIDY3D},
-		scale_input_sockets={
-			'Center': 'Tidy3DUnits',
-			'Size': 'Tidy3DUnits',
-			'Freqs': 'Tidy3DUnits',
-		},
-	)
-	def compute_freq_monitor(
-		self,
-		input_sockets: dict,
-		props: dict,
-		unit_systems: dict,
-	) -> td.FieldMonitor:
-		log.info(
-			'Computing FieldMonitor (name="%s") with center="%s", size="%s"',
-			props['sim_node_name'],
-			input_sockets['Center'],
-			input_sockets['Size'],
-		)
-		return td.FieldMonitor(
-			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,
-			fields=props['fields'],
-		)
-
-	@events.computes_output_socket(
-		'Time Monitor',
-		props={'sim_node_name', 'fields'},
-		input_sockets={
-			'Center',
-			'Size',
-			'Stride',
 			't Range',
 			't Stride',
 		},
 		input_socket_kinds={
-			't Range': ct.FlowKind.Range,
-		},
-		unit_systems={'Tidy3DUnits': ct.UNITS_TIDY3D},
-		scale_input_sockets={
-			'Center': 'Tidy3DUnits',
-			'Size': 'Tidy3DUnits',
-			't Range': 'Tidy3DUnits',
+			'Center': ct.FlowKind.Func,
+			'Size': ct.FlowKind.Func,
+			'Stride': ct.FlowKind.Func,
+			'Freqs': ct.FlowKind.Func,
+			't Range': ct.FlowKind.Func,
+			't Stride': ct.FlowKind.Func,
 		},
 	)
-	def compute_time_monitor(
-		self,
-		input_sockets: dict,
-		props: dict,
-		unit_systems: dict,
-	) -> td.FieldMonitor:
-		log.info(
-			'Computing FieldMonitor (name="%s") with center="%s", size="%s"',
-			props['sim_node_name'],
-			input_sockets['Center'],
-			input_sockets['Size'],
-		)
-		return td.FieldTimeMonitor(
-			center=input_sockets['Center'],
-			size=input_sockets['Size'],
-			name=props['sim_node_name'],
-			interval_space=tuple(input_sockets['Stride']),
-			start=input_sockets['t Range'].realize_start(),
-			stop=input_sockets['t Range'].realize_stop(),
-			interval=input_sockets['t Stride'],
-			fields=props['fields'],
-		)
+	def compute_func(self, props, input_sockets) -> td.FieldMonitor:
+		center = input_sockets['Center']
+		size = input_sockets['Size']
+		stride = input_sockets['Stride']
+
+		has_center = not ct.FlowSignal.check(center)
+		has_size = not ct.FlowSignal.check(size)
+		has_stride = not ct.FlowSignal.check(stride)
+
+		if has_center and has_size and has_stride:
+			name = props['sim_node_name']
+			fields = props['fields']
+
+			common_func_flow = (
+				center.scale_to_unit_system(ct.UNITS_TIDY3D)
+				| size.scale_to_unit_system(ct.UNITS_TIDY3D)
+				| stride
+			)
+
+			match props['active_socket_set']:
+				case 'Freq Domain':
+					freqs = input_sockets['Freqs']
+					has_freqs = not ct.FlowSignal.check(freqs)
+
+					if has_freqs:
+						return (
+							common_func_flow
+							| freqs.scale_to_unit_system(ct.UNITS_TIDY3D)
+						).compose_within(
+							lambda els: td.FieldMonitor(
+								center=els[0].flatten().tolist(),
+								size=els[1].flatten().tolist(),
+								name=name,
+								interval_space=els[2].flatten().tolist(),
+								freqs=els[3].flatten(),
+								fields=fields,
+							)
+						)
+
+				case 'Time Domain':
+					t_range = input_sockets['t Range']
+					t_stride = input_sockets['t Stride']
+
+					has_t_range = not ct.FlowSignal.check(t_range)
+					has_t_stride = not ct.FlowSignal.check(t_stride)
+
+					if has_t_range and has_t_stride:
+						return (
+							common_func_flow
+							| t_range.scale_to_unit_system(ct.UNITS_TIDY3D)
+							| t_stride.scale_to_unit_system(ct.UNITS_TIDY3D)
+						).compose_within(
+							lambda els: td.FieldTimeMonitor(
+								center=els[0].flatten().tolist(),
+								size=els[1].flatten().tolist(),
+								name=name,
+								interval_space=els[2].flatten().tolist(),
+								start=els[3][0],
+								stop=els[3][-1],
+								interval=els[4],
+								fields=fields,
+							)
+						)
+		return ct.FlowSignal.FlowPending
+
+	####################
+	# - FlowKind.Params
+	####################
+	@events.computes_output_socket(
+		'Monitor',
+		kind=ct.FlowKind.Params,
+		# Loaded
+		props={'active_socket_set'},
+		input_sockets={
+			'Center',
+			'Size',
+			'Stride',
+			'Freqs',
+			't Range',
+			't Stride',
+		},
+		input_socket_kinds={
+			'Center': ct.FlowKind.Params,
+			'Size': ct.FlowKind.Params,
+			'Stride': ct.FlowKind.Params,
+			'Freqs': ct.FlowKind.Params,
+			't Range': ct.FlowKind.Params,
+			't Stride': ct.FlowKind.Params,
+		},
+	)
+	def compute_params(self, props, input_sockets) -> None:
+		center = input_sockets['Center']
+		size = input_sockets['Size']
+		stride = input_sockets['Stride']
+
+		has_center = not ct.FlowSignal.check(center)
+		has_size = not ct.FlowSignal.check(size)
+		has_stride = not ct.FlowSignal.check(stride)
+
+		if has_center and has_size and has_stride:
+			common_params = center | size | stride
+			match props['active_socket_set']:
+				case 'Freq Domain':
+					freqs = input_sockets['Freqs']
+					has_freqs = not ct.FlowSignal.check(freqs)
+
+					if has_freqs:
+						return common_params | freqs
+
+				case 'Time Domain':
+					t_range = input_sockets['t Range']
+					t_stride = input_sockets['t Stride']
+
+					has_t_range = not ct.FlowSignal.check(t_range)
+					has_t_stride = not ct.FlowSignal.check(t_stride)
+
+					if has_t_range and has_t_stride:
+						return common_params | t_range | t_stride
+		return ct.FlowSignal.FlowPending
 
 	####################
 	# - Preview
 	####################
 	@events.computes_output_socket(
-		'Time Monitor',
+		'Monitor',
 		kind=ct.FlowKind.Previews,
 		# Loaded
 		props={'sim_node_name'},
+		output_sockets={'Monitor'},
+		output_socket_kinds={'Monitor': ct.FlowKind.Params},
 	)
-	def compute_previews_time(self, props):
-		return ct.PreviewsFlow(bl_object_names={props['sim_node_name']})
+	def compute_previews(self, props, output_sockets):
+		output_params = output_sockets['Monitor']
+		has_output_params = not ct.FlowSignal.check(output_params)
 
-	@events.computes_output_socket(
-		'Freq Monitor',
-		kind=ct.FlowKind.Previews,
-		# Loaded
-		props={'sim_node_name'},
-	)
-	def compute_previews_freq(self, props):
-		return ct.PreviewsFlow(bl_object_names={props['sim_node_name']})
+		if has_output_params and not output_params.symbols:
+			return ct.PreviewsFlow(bl_object_names={props['sim_node_name']})
+		return ct.PreviewsFlow()
 
 	@events.on_value_changed(
 		# Trigger
@@ -220,29 +298,31 @@ class EHFieldMonitorNode(base.MaxwellSimNode):
 		# Loaded
 		managed_objs={'modifier'},
 		input_sockets={'Center', 'Size'},
-		unit_systems={'BlenderUnits': ct.UNITS_BLENDER},
-		scale_input_sockets={
-			'Center': 'BlenderUnits',
-		},
+		output_sockets={'Monitor'},
+		output_socket_kinds={'Monitor': ct.FlowKind.Params},
 	)
-	def on_inputs_changed(
-		self,
-		managed_objs,
-		input_sockets,
-		unit_systems,
-	):
-		# Push Input Values to GeoNodes Modifier
-		managed_objs['modifier'].bl_modifier(
-			'NODES',
-			{
-				'node_group': import_geonodes(GeoNodes.MonitorEHField),
-				'unit_system': unit_systems['BlenderUnits'],
-				'inputs': {
-					'Size': input_sockets['Size'],
+	def on_previewable_changed(self, managed_objs, input_sockets, output_sockets):
+		center = input_sockets['Center']
+		size = input_sockets['Size']
+		output_params = output_sockets['Monitor']
+
+		has_center = not ct.FlowSignal.check(center)
+		has_size = not ct.FlowSignal.check(size)
+		has_output_params = not ct.FlowSignal.check(output_params)
+
+		if has_center and has_size and has_output_params and not output_params.symbols:
+			# Push Input Values to GeoNodes Modifier
+			managed_objs['modifier'].bl_modifier(
+				'NODES',
+				{
+					'node_group': import_geonodes(GeoNodes.MonitorEHField),
+					'unit_system': ct.UNITS_BLENDER,
+					'inputs': {
+						'Size': size,
+					},
 				},
-			},
-			location=input_sockets['Center'],
-		)
+				location=spux.scale_to_unit_system(center, ct.UNITS_BLENDER),
+			)
 
 
 ####################

src/blender_maxwell/node_trees/maxwell_sim_nodes/nodes/simulations/combine.py

@@ -163,7 +163,9 @@ class CombineNode(base.MaxwellSimNode):
 					if not ct.FlowSignal.check(inp)
 				]
 				if func_flows:
-					return func_flows
+					return functools.reduce(
+						lambda a, b: a | b, func_flows
+					).compose_within(lambda els: list(els))
 				return ct.FlowSignal.FlowPending
 
 			case (ct.FlowKind.Func, ct.FlowKind.Params):
@@ -171,11 +173,13 @@ class CombineNode(base.MaxwellSimNode):
 					params_flow
 					for inp_sckname in self.inputs.keys()  # noqa: SIM118
 					if not ct.FlowSignal.check(
-						params_flow := self._compute_input(inp_sckname, kind='params')
+						params_flow := self._compute_input(
+							inp_sckname, kind=ct.FlowKind.Params
+						)
 					)
 				]
 				if params_flows:
-					return params_flows
+					return functools.reduce(lambda a, b: a | b, params_flows)
 				return ct.FlowSignal.FlowPending
 
 		return ct.FlowSignal.FlowPending

src/blender_maxwell/node_trees/maxwell_sim_nodes/nodes/simulations/fdtd_sim.py

@@ -57,10 +57,7 @@ class FDTDSimNode(base.MaxwellSimNode):
 		'Single': {
 			'Sim': sockets.MaxwellFDTDSimSocketDef(active_kind=ct.FlowKind.Value),
 		},
-		'Batch': {
-			'Sim': sockets.MaxwellFDTDSimSocketDef(active_kind=ct.FlowKind.Array),
-		},
-		'Lazy': {
+		'Func': {
 			'Sim': sockets.MaxwellFDTDSimSocketDef(active_kind=ct.FlowKind.Func),
 		},
 	}
@@ -101,7 +98,7 @@ class FDTDSimNode(base.MaxwellSimNode):
 		# Declare Loose Sockets that Realize Symbols
 		## -> This happens if Params contains not-yet-realized symbols.
 		active_socket_set = props['active_socket_set']
-		if active_socket_set in ['Value', 'Batch'] and has_params and params.symbols:
+		if active_socket_set == 'Single' and has_params and params.symbols:
 			if set(self.loose_input_sockets) != {sym.name for sym in params.symbols}:
 				self.loose_input_sockets = {
 					sym.name: sockets.ExprSocketDef(
@@ -128,51 +125,19 @@ class FDTDSimNode(base.MaxwellSimNode):
 		'Sim',
 		kind=ct.FlowKind.Value,
 		# Loaded
-		props={'differentiable'},
-		input_sockets={'Sources', 'Structures', 'Domain', 'BCs', 'Monitors'},
-		input_socket_kinds={
-			'Sources': ct.FlowKind.Array,
-			'Structures': ct.FlowKind.Array,
-			'Monitors': ct.FlowKind.Array,
-		},
 		output_sockets={'Sim'},
-		output_socket_kinds={'Sim': ct.FlowKind.Params},
+		output_socket_kinds={'Sim': {ct.FlowKind.Func, ct.FlowKind.Params}},
 	)
-	def compute_fdtd_sim_value(
-		self, props, input_sockets, output_sockets
-	) -> td.Simulation | tdadj.JaxSimulation | ct.FlowSignal:
-		"""Compute a single FDTD simulation definition, so long as the inputs are neither symbolic or differentiable."""
-		sim_domain = input_sockets['Domain']
-		sources = input_sockets['Sources']
-		structures = input_sockets['Structures']
-		bounds = input_sockets['BCs']
-		monitors = input_sockets['Monitors']
-		output_params = output_sockets['Sim']
+	def compute_value(self, output_sockets) -> ct.ParamsFlow | ct.FlowSignal:
+		"""Compute the particular value of the simulation domain from strictly non-symbolic inputs."""
+		output_func = output_sockets['Sim'][ct.FlowKind.Func]
+		output_params = output_sockets['Sim'][ct.FlowKind.Params]
 
-		has_sim_domain = not ct.FlowSignal.check(sim_domain)
-		has_sources = not ct.FlowSignal.check(sources)
-		has_structures = not ct.FlowSignal.check(structures)
-		has_bounds = not ct.FlowSignal.check(bounds)
-		has_monitors = not ct.FlowSignal.check(monitors)
+		has_output_func = not ct.FlowSignal.check(output_func)
 		has_output_params = not ct.FlowSignal.check(output_params)
 
-		differentiable = props['differentiable']
-		if (
-			has_sim_domain
-			and has_sources
-			and has_structures
-			and has_bounds
-			and has_monitors
-			and has_output_params
-			and not differentiable
-		):
-			return td.Simulation(
-				**sim_domain,
-				sources=sources,
-				structures=structures,
-				boundary_spec=bounds,
-				monitors=monitors,
-			)
+		if has_output_func and has_output_params and not output_params.symbols:
+			return output_func.realize(output_params, disallow_jax=True)
 		return ct.FlowSignal.FlowPending
 
 	####################
@@ -185,6 +150,8 @@ class FDTDSimNode(base.MaxwellSimNode):
 		props={'differentiable'},
 		input_sockets={'Sources', 'Structures', 'Domain', 'BCs', 'Monitors'},
 		input_socket_kinds={
+			'BCs': ct.FlowKind.Func,
+			'Domain': ct.FlowKind.Func,
 			'Sources': ct.FlowKind.Func,
 			'Structures': ct.FlowKind.Func,
 			'Monitors': ct.FlowKind.Func,
@@ -196,17 +163,17 @@ class FDTDSimNode(base.MaxwellSimNode):
 		self, props, input_sockets, output_sockets
 	) -> td.Simulation | tdadj.JaxSimulation | ct.FlowSignal:
 		"""Compute a single simulation, given that all inputs are non-symbolic."""
+		bounds = input_sockets['BCs']
 		sim_domain = input_sockets['Domain']
 		sources = input_sockets['Sources']
 		structures = input_sockets['Structures']
-		bounds = input_sockets['BCs']
 		monitors = input_sockets['Monitors']
 		output_params = output_sockets['Sim']
 
+		has_bounds = not ct.FlowSignal.check(bounds)
 		has_sim_domain = not ct.FlowSignal.check(sim_domain)
 		has_sources = not ct.FlowSignal.check(sources)
 		has_structures = not ct.FlowSignal.check(structures)
-		has_bounds = not ct.FlowSignal.check(bounds)
 		has_monitors = not ct.FlowSignal.check(monitors)
 		has_output_params = not ct.FlowSignal.check(output_params)
 
@@ -220,28 +187,16 @@ class FDTDSimNode(base.MaxwellSimNode):
 		):
 			differentiable = props['differentiable']
 			if differentiable:
-				return (
-					sim_domain | sources | structures | bounds | monitors
-				).compose_within(
-					enclosing_func=lambda els: tdadj.JaxSimulation(
-						**els[0],
-						sources=els[1],
-						structures=els[2]['static'],
-						input_structures=els[2]['differentiable'],
-						boundary_spec=els[3],
-						monitors=els[4]['static'],
-						output_monitors=els[4]['differentiable'],
-					),
-					supports_jax=True,
-				)
+				raise NotImplementedError
+
 			return (
-				sim_domain | sources | structures | bounds | monitors
+				bounds | sim_domain | sources | structures | monitors
 			).compose_within(
 				enclosing_func=lambda els: td.Simulation(
-					**els[0],
-					sources=els[1],
-					structures=els[2],
-					boundary_spec=els[3],
+					boundary_spec=els[0],
+					**els[1],
+					sources=els[2],
+					structures=els[3],
 					monitors=els[4],
 				),
 				supports_jax=False,
@@ -258,6 +213,8 @@ class FDTDSimNode(base.MaxwellSimNode):
 		props={'differentiable'},
 		input_sockets={'Sources', 'Structures', 'Domain', 'BCs', 'Monitors'},
 		input_socket_kinds={
+			'BCs': ct.FlowKind.Params,
+			'Domain': ct.FlowKind.Params,
 			'Sources': ct.FlowKind.Params,
 			'Structures': ct.FlowKind.Params,
 			'Monitors': ct.FlowKind.Params,
@@ -267,31 +224,26 @@ class FDTDSimNode(base.MaxwellSimNode):
 		self, props, input_sockets
 	) -> td.Simulation | tdadj.JaxSimulation | ct.FlowSignal:
 		"""Compute a single simulation, given that all inputs are non-symbolic."""
+		bounds = input_sockets['BCs']
 		sim_domain = input_sockets['Domain']
 		sources = input_sockets['Sources']
 		structures = input_sockets['Structures']
-		bounds = input_sockets['BCs']
 		monitors = input_sockets['Monitors']
 
+		has_bounds = not ct.FlowSignal.check(bounds)
 		has_sim_domain = not ct.FlowSignal.check(sim_domain)
 		has_sources = not ct.FlowSignal.check(sources)
 		has_structures = not ct.FlowSignal.check(structures)
-		has_bounds = not ct.FlowSignal.check(bounds)
 		has_monitors = not ct.FlowSignal.check(monitors)
 
 		if (
-			has_sim_domain
+			has_bounds
+			and has_sim_domain
 			and has_sources
 			and has_structures
-			and has_bounds
 			and has_monitors
 		):
-			# Determine Differentiable Match
-			## -> 'structures' is diff when **any** are diff.
-			## -> 'monitors' is also diff when **any** are diff.
-			## -> Only parameters through diff structs can be diff'ed by.
-			## -> Similarly, only diff monitors will have gradients computed.
-			return sim_domain | sources | structures | bounds | monitors
+			return bounds | sim_domain | sources | structures | monitors
 		return ct.FlowSignal.FlowPending
 
 

src/blender_maxwell/node_trees/maxwell_sim_nodes/nodes/sources/plane_wave_source.py

@@ -71,7 +71,7 @@ class PlaneWaveSourceNode(base.MaxwellSimNode):
 		),
 	}
 	output_sockets: typ.ClassVar = {
-		'Angled Source': sockets.MaxwellSourceSocketDef(),
+		'Angled Source': sockets.MaxwellSourceSocketDef(active_kind=ct.FlowKind.Func),
 	}
 
 	managed_obj_types: typ.ClassVar = {
@@ -103,8 +103,8 @@ class PlaneWaveSourceNode(base.MaxwellSimNode):
 	)
 	def compute_value(self, output_sockets) -> ct.ParamsFlow | ct.FlowSignal:
 		"""Compute the particular value of the simulation domain from strictly non-symbolic inputs."""
-		output_func = output_sockets['Source'][ct.FlowKind.Func]
-		output_params = output_sockets['Source'][ct.FlowKind.Params]
+		output_func = output_sockets['Angled Source'][ct.FlowKind.Func]
+		output_params = output_sockets['Angled Source'][ct.FlowKind.Params]
 
 		has_output_func = not ct.FlowSignal.check(output_func)
 		has_output_params = not ct.FlowSignal.check(output_params)
@@ -122,11 +122,11 @@ class PlaneWaveSourceNode(base.MaxwellSimNode):
 		# Loaded
 		props={'sim_node_name', 'injection_axis', 'injection_direction'},
 		input_sockets={'Temporal Shape', 'Center', 'Spherical', 'Pol ∡'},
-		unit_systems={'Tidy3DUnits': ct.UNITS_TIDY3D},
-		scale_input_sockets={
-			'Center': 'Tidy3DUnits',
-			'Spherical': 'Tidy3DUnits',
-			'Pol ∡': 'Tidy3DUnits',
+		input_socket_kinds={
+			'Temporal Shape': ct.FlowKind.Func,
+			'Center': ct.FlowKind.Func,
+			'Spherical': ct.FlowKind.Func,
+			'Pol ∡': ct.FlowKind.Func,
 		},
 	)
 	def compute_func(self, props, input_sockets) -> None:
@@ -157,17 +157,47 @@ class PlaneWaveSourceNode(base.MaxwellSimNode):
 			).compose_within(
 				lambda els: td.PlaneWave(
 					name=name,
-					center=els[0],
+					center=els[0].flatten().tolist(),
 					size=size,
 					source_time=els[1],
 					direction=inj_dir,
-					angle_theta=els[2][0],
-					angle_phi=els[2][1],
+					angle_theta=els[2][0].item(0),
+					angle_phi=els[2][1].item(0),
 					pol_angle=els[3],
 				)
 			)
 		return ct.FlowSignal.FlowPending
 
+	####################
+	# - FlowKind.Params
+	####################
+	@events.computes_output_socket(
+		'Angled Source',
+		kind=ct.FlowKind.Params,
+		# Loaded
+		input_sockets={'Temporal Shape', 'Center', 'Spherical', 'Pol ∡'},
+		input_socket_kinds={
+			'Temporal Shape': ct.FlowKind.Params,
+			'Center': ct.FlowKind.Params,
+			'Spherical': ct.FlowKind.Params,
+			'Pol ∡': ct.FlowKind.Params,
+		},
+	)
+	def compute_params(self, input_sockets) -> None:
+		center = input_sockets['Center']
+		temporal_shape = input_sockets['Temporal Shape']
+		spherical = input_sockets['Spherical']
+		pol_ang = input_sockets['Pol ∡']
+
+		has_center = not ct.FlowSignal.check(center)
+		has_temporal_shape = not ct.FlowSignal.check(temporal_shape)
+		has_spherical = not ct.FlowSignal.check(spherical)
+		has_pol_ang = not ct.FlowSignal.check(pol_ang)
+
+		if has_center and has_temporal_shape and has_spherical and has_pol_ang:
+			return center | temporal_shape | spherical | pol_ang
+		return ct.FlowSignal.FlowPending
+
 	####################
 	# - Preview - Changes to Input Sockets
 	####################
@@ -176,11 +206,11 @@ class PlaneWaveSourceNode(base.MaxwellSimNode):
 		kind=ct.FlowKind.Previews,
 		# Loaded
 		props={'sim_node_name'},
-		output_sockets={'Structure'},
-		output_socket_kinds={'Structure': ct.FlowKind.Params},
+		output_sockets={'Angled Source'},
+		output_socket_kinds={'Angled Source': ct.FlowKind.Params},
 	)
 	def compute_previews(self, props, output_sockets):
-		output_params = output_sockets['Structure']
+		output_params = output_sockets['Angled Source']
 		has_output_params = not ct.FlowSignal.check(output_params)
 
 		if has_output_params and not output_params.symbols:
@@ -199,7 +229,9 @@ class PlaneWaveSourceNode(base.MaxwellSimNode):
 		output_sockets={'Angled Source'},
 		output_socket_kinds={'Angled Source': ct.FlowKind.Params},
 	)
-	def on_inputs_changed(self, managed_objs, props, input_sockets, output_sockets):
+	def on_previewable_changed(
+		self, managed_objs, props, input_sockets, output_sockets
+	):
 		center = input_sockets['Center']
 		spherical = input_sockets['Spherical']
 		pol_ang = input_sockets['Pol ∡']

src/blender_maxwell/node_trees/maxwell_sim_nodes/nodes/sources/point_dipole_source.py

@@ -172,11 +172,11 @@ class PointDipoleSourceNode(base.MaxwellSimNode):
 		kind=ct.FlowKind.Previews,
 		# Loaded
 		props={'sim_node_name'},
-		output_sockets={'Structure'},
-		output_socket_kinds={'Structure': ct.FlowKind.Params},
+		output_sockets={'Source'},
+		output_socket_kinds={'Source': ct.FlowKind.Params},
 	)
 	def compute_previews(self, props, output_sockets):
-		output_params = output_sockets['Structure']
+		output_params = output_sockets['Source']
 		has_output_params = not ct.FlowSignal.check(output_params)
 
 		if has_output_params and not output_params.symbols:
@@ -184,6 +184,7 @@ class PointDipoleSourceNode(base.MaxwellSimNode):
 		return ct.PreviewsFlow()
 
 	@events.on_value_changed(
+		# Trigger
 		socket_name={'Center'},
 		prop_name='pol',
 		run_on_init=True,
@@ -194,7 +195,7 @@ class PointDipoleSourceNode(base.MaxwellSimNode):
 		output_sockets={'Source'},
 		output_socket_kinds={'Source': ct.FlowKind.Params},
 	)
-	def on_inputs_changed(
+	def on_previewable_changed(
 		self, managed_objs, props, input_sockets, output_sockets
 	) -> None:
 		SFP = ct.SimFieldPols
@@ -220,8 +221,10 @@ class PointDipoleSourceNode(base.MaxwellSimNode):
 				'NODES',
 				{
 					'node_group': import_geonodes(GeoNodes.SourcePointDipole),
-					'inputs': {'Axis': axis},
 					'unit_system': ct.UNITS_BLENDER,
+					'inputs': {
+						'Axis': axis,
+					},
 				},
 				location=spux.scale_to_unit_system(center, ct.UNITS_BLENDER),
 			)

src/blender_maxwell/node_trees/maxwell_sim_nodes/nodes/structures/primitives/box_structure.py

@@ -213,8 +213,8 @@ class BoxStructureNode(base.MaxwellSimNode):
 		socket_name={'Center', 'Size'},
 		run_on_init=True,
 		# Loaded
-		input_sockets={'Center', 'Size'},
 		managed_objs={'modifier'},
+		input_sockets={'Center', 'Size'},
 		output_sockets={'Structure'},
 		output_socket_kinds={'Structure': ct.FlowKind.Params},
 	)

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

@@ -282,9 +282,9 @@ class MaxwellSimSocket(bpy.types.NodeSocket, bl_instance.BLInstance):
 
 			# Property Callbacks: Per-Socket
 			## -> NOTE: User-defined handlers might recurse on_prop_changed.
-			self.is_initializing = True
+			# self.is_initializing = True
 			self.on_socket_props_changed(set_of_cleared_blfields)
-			self.is_initializing = False
+			# self.is_initializing = False
 
 			# Trigger Event
 			## -> Before SocketDef.postinit(), never emit DataChanged.

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

@@ -408,7 +408,7 @@ class ExprBLSocket(base.MaxwellSimSocket):
 		## NOTE: Depends on suppressed on_prop_changed
 		if ('selected_value_range', 'invalidate') in cleared_blfields:
 			self.active_kind = self.selected_value_range
-			self.on_active_kind_changed()
+			# self.on_active_kind_changed()
 
 		# Conditional Unit-Conversion
 		## -> This is niche functionality, but the only way to convert units.
@@ -434,6 +434,7 @@ class ExprBLSocket(base.MaxwellSimSocket):
 				self.lazy_range = self.lazy_range.correct_unit(prev_unit)
 
 			self.prev_unit = self.active_unit
+			# self.unit = bl_cache.Signal.InvalidateCache
 
 	####################
 	# - Value Utilities
@@ -843,7 +844,9 @@ class ExprBLSocket(base.MaxwellSimSocket):
 
 		return ct.FlowSignal.FlowPending
 
-	@bl_cache.cached_bl_property(depends_on={'sorted_symbols', 'output_sym'})
+	@bl_cache.cached_bl_property(
+		depends_on={'sorted_symbols', 'output_sym', 'lazy_range'}
+	)
 	def info(self) -> ct.InfoFlow:
 		r"""Returns parameter symbols/values to accompany `self.lazy_func`.
 

src/blender_maxwell/utils/bl_cache/bl_field.py

@@ -307,7 +307,14 @@ class BLField:
 		## -> As a result, the value must be reloaded from the property.
 		## The 'on_prop_changed' method on the bl_instance might also be called.
 		if value is Signal.InvalidateCache or value is Signal.InvalidateCacheNoUpdate:
-			self.bl_prop.invalidate_nonpersist(bl_instance)
+			# Invalidate Non-Persistent Cache
+			## -> Invalidations via on_bl_prop_changed may come by here.
+			## -> In many cases, we may have suppressed that BLProp.write().
+			## -> BLProp.write() itself guarantees inv. of non-persist cache.
+			## -> In the meantime, don't strip away thread safety!
+			## -> (Dict ops are thread-safe in CPython; Blender Props are NOT)
+			if not self.suppressed_update.get(bl_instance.instance_id, False):
+				self.bl_prop.invalidate_nonpersist(bl_instance)
 
 			# Trigger Update Chain
 			## -> User can disable w/'use_prop_update=False'.

src/blender_maxwell/utils/bl_cache/cached_bl_property.py

@@ -182,20 +182,23 @@ class CachedBLProperty:
 				# Fill Caches
 				## -> persist=True: Fill Persist and Non-Persist Cache
 				## -> persist=False: Fill Non-Persist Cache
-				if self.persist:
-					with self.suppress_update(bl_instance):
-						self.bl_prop.write(bl_instance, self.getter_method(bl_instance))
+				if not self.suppressed_update.get(bl_instance.instance_id, False):
+					if self.persist:
+						with self.suppress_update(bl_instance):
+							self.bl_prop.write(
+								bl_instance, self.getter_method(bl_instance)
+							)
 
-				else:
-					self.bl_prop.write_nonpersist(
-						bl_instance, self.getter_method(bl_instance)
-					)
+					else:
+						self.bl_prop.write_nonpersist(
+							bl_instance, self.getter_method(bl_instance)
+						)
 
 				# Trigger Update
 				## -> Use InvalidateCacheNoUpdate to explicitly disable update.
 				## -> If 'suppress_update' context manager is active, don't update.
 				if value is Signal.InvalidateCache and not self.suppressed_update.get(
-					bl_instance.instance_id
+					bl_instance.instance_id, False
 				):
 					bl_instance.on_prop_changed(self.bl_prop.name)
 

src/blender_maxwell/utils/extra_sympy_units.py

@@ -1408,7 +1408,11 @@ class PhysicalType(enum.StrEnum):
 			ValueError: If no `PhysicalType` could be matched, and `optional` is `False`.
 		"""
 		if unit is None:
-			return ct.PhysicalType.NonPhysical
+			return PhysicalType.NonPhysical
+
+		## TODO_ This enough?
+		if unit in [spu.radian, spu.degree]:
+			return PhysicalType.Angle
 
 		unit_dim_deps = unit_to_unit_dim_deps(unit)
 		if unit_dim_deps is not None: