feat: add deterministic simulation foundation

Replace implicit randomness with seeded per-NPC RandomNumberGenerator
streams so the same seed always produces the same scenario outcome.

- Add SimulationClock (RefCounted): explicit fixed-step clock that
  converts frame delta into simulation ticks while preserving sub-tick
  remainder; replaces raw _process tick_timer accumulation
- Add simulation_seed export (int=1337) to SimulationManager; drive
  per-NPC RNG streams via seed + npc_id + stream_id derivation
  (stream 0=init, stream 1=wander)
- Add get_wander_offset(npc_id) to SimulationManager so wander targets
  are deterministic per seed; WorldViewManager calls it instead of
  local randf_range()
- Add get_state_snapshot() and get_state_checksum() to SimulationManager
  for headless verification and future save/load
- Convert SimNPC/SimVillage const DEBUG_LOGS to instance var debug_logs
  so headless tests can silence output without recompilation
- Pass RandomNumberGenerator through SimNPC._init() instead of using
  global randf_range() for hunger/energy/position/scoring noise
- Remove obsolete farm_zone and forest_zone exports from
  WorldViewManager and their marker/tree scene children from main.tscn;
  NPC gather tasks use ResourceNode exclusively
- Rename TaskZone container to ActivityMarkers in main.tscn and update
  all scene paths (player, WVM, tests) to match
- Add headless deterministic_simulation_test.gd: verifies clock
  accuracy, same-seed equality, different-seed divergence, and
  24-tick scenario checksum without loading main.tscn

main.tscn

@@ -5,9 +5,7 @@
 [ext_resource type="Script" uid="uid://dbb25ttlyogqr" path="res://simulation/SimulationManager.gd" id="3_lquwl"]
 [ext_resource type="Script" uid="uid://c1f3b26n4yntf" path="res://world/world_view_manager.gd" id="4_1bvp3"]
 [ext_resource type="PackedScene" uid="uid://dhxxyprqflotq" path="res://player/npc/NpcVisual.tscn" id="5_lquwl"]
-[ext_resource type="PackedScene" uid="uid://q0w3en4bfk42" path="res://assets/foliage/tree.glb" id="6_5vw27"]
 [ext_resource type="Script" uid="uid://cjvbgqx8rao0t" path="res://world/ui/ui.gd" id="6_7mycd"]
-[ext_resource type="PackedScene" uid="uid://dyu3r0cl0judq" path="res://assets/foliage/tree-high.glb" id="7_kek77"]
 [ext_resource type="PackedScene" uid="uid://dvd3qjpjor4sq" path="res://world/resource_nodes/ResourceNode.tscn" id="8_r3s0u"]
 
 [sub_resource type="NavigationMesh" id="NavigationMesh_lquwl"]
@@ -37,12 +35,6 @@ ambient_light_source = 2
 ambient_light_color = Color(1, 1, 1, 1)
 ambient_light_energy = 0.5
 
-[sub_resource type="StandardMaterial3D" id="StandardMaterial3D_5vw27"]
-albedo_color = Color(0.5328383, 0.4215183, 0.18649894, 1)
-
-[sub_resource type="BoxMesh" id="BoxMesh_5vw27"]
-material = SubResource("StandardMaterial3D_5vw27")
-
 [sub_resource type="CylinderMesh" id="CylinderMesh_5vw27"]
 top_radius = 1.129
 height = 5.774
@@ -82,9 +74,9 @@ transform = Transform3D(1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0.05, 0)
 script = ExtResource("1_h2yge")
 camera_rig = NodePath("../CameraRig")
 simulation_manager = NodePath("../SimulationManager")
-food_zone = NodePath("../TaskZone/FoodZone")
+food_zone = NodePath("../ActivityMarkers/FoodZone")
-guard_zone = NodePath("../TaskZone/GuardZone")
+guard_zone = NodePath("../ActivityMarkers/GuardZone")
-study_zone = NodePath("../TaskZone/StudyZone")
+study_zone = NodePath("../ActivityMarkers/StudyZone")
 stomach_capacity_for_food = 10
 
 [node name="CollisionShape3D" type="CollisionShape3D" parent="Player" unique_id=1249497228]
@@ -114,17 +106,15 @@ fov = 65.0
 [node name="SimulationManager" type="Node" parent="." unique_id=1099676814]
 script = ExtResource("3_lquwl")
 
-[node name="WorldViewManager" type="Node" parent="." unique_id=763982891 node_paths=PackedStringArray("simulation_manager", "active_npcs_parent", "farm_zone", "forest_zone", "guard_zone", "study_zone", "rest_zone", "food_zone")]
+[node name="WorldViewManager" type="Node" parent="." unique_id=763982891 node_paths=PackedStringArray("simulation_manager", "active_npcs_parent", "guard_zone", "study_zone", "rest_zone", "food_zone")]
 script = ExtResource("4_1bvp3")
 npc_visual_scene = ExtResource("5_lquwl")
 simulation_manager = NodePath("../SimulationManager")
 active_npcs_parent = NodePath("../ActiveNPCs")
-farm_zone = NodePath("../TaskZone/FarmZone")
+guard_zone = NodePath("../ActivityMarkers/GuardZone")
-forest_zone = NodePath("../TaskZone/ForestZone")
+study_zone = NodePath("../ActivityMarkers/StudyZone")
-guard_zone = NodePath("../TaskZone/GuardZone")
+rest_zone = NodePath("../ActivityMarkers/RestZone")
-study_zone = NodePath("../TaskZone/StudyZone")
+food_zone = NodePath("../ActivityMarkers/FoodZone")
-rest_zone = NodePath("../TaskZone/RestZone")
-food_zone = NodePath("../TaskZone/FoodZone")
 
 [node name="EventBus" type="Node" parent="." unique_id=1149294963]
 
@@ -133,60 +123,38 @@ environment = SubResource("Environment_o5qli")
 
 [node name="ActiveNPCs" type="Node3D" parent="." unique_id=88374680]
 
-[node name="TaskZone" type="Node3D" parent="." unique_id=1700020332]
+[node name="ActivityMarkers" type="Node3D" parent="." unique_id=1700020332]
 
-[node name="FarmZone" type="Marker3D" parent="TaskZone" unique_id=786703634]
+[node name="GuardZone" type="Marker3D" parent="ActivityMarkers" unique_id=1391821683]
-transform = Transform3D(1, 0, 0, 0, 1, 0, 0, 0, 1, -8, 0, -6)
-
-[node name="MeshInstance3D" type="MeshInstance3D" parent="TaskZone/FarmZone" unique_id=35196509]
-transform = Transform3D(2.0639582, 0, 0, 0, 0.2, 0, 0, 0, 2.211021, -0.47271156, 0.47702956, -0.02484417)
-mesh = SubResource("BoxMesh_5vw27")
-
-[node name="ForestZone" type="Marker3D" parent="TaskZone" unique_id=1194368101]
-transform = Transform3D(1, 0, 0, 0, 1, 0, 0, 0, 1, 8, 0, -6)
-
-[node name="smallTree" parent="TaskZone/ForestZone" unique_id=1125781625 instance=ExtResource("6_5vw27")]
-transform = Transform3D(3, 0, 0, 0, 3, 0, 0, 0, 3, 1.891, 0, -0.22)
-
-[node name="smallTree2" parent="TaskZone/ForestZone" unique_id=1145526891 instance=ExtResource("6_5vw27")]
-transform = Transform3D(2, 0, 0, 0, 2, 0, 0, 0, 2, -0.043, 0, -1.767)
-
-[node name="smallTree3" parent="TaskZone/ForestZone" unique_id=759036058 instance=ExtResource("6_5vw27")]
-transform = Transform3D(3, 0, 0, 0, 3, 0, 0, 0, 3, 0.13, 0, 0.614)
-
-[node name="highTree" parent="TaskZone/ForestZone" unique_id=1321501180 instance=ExtResource("7_kek77")]
-transform = Transform3D(3, 0, 0, 0, 3, 0, 0, 0, 3, -1.539, 0, 0.171)
-
-[node name="GuardZone" type="Marker3D" parent="TaskZone" unique_id=1391821683]
 transform = Transform3D(1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 8)
 
-[node name="MeshInstance3D" type="MeshInstance3D" parent="TaskZone/GuardZone" unique_id=2044200724]
+[node name="MeshInstance3D" type="MeshInstance3D" parent="ActivityMarkers/GuardZone" unique_id=2044200724]
 transform = Transform3D(1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 1.354011, 0)
 mesh = SubResource("CylinderMesh_5vw27")
 
-[node name="StudyZone" type="Marker3D" parent="TaskZone" unique_id=1061191663]
+[node name="StudyZone" type="Marker3D" parent="ActivityMarkers" unique_id=1061191663]
 transform = Transform3D(1, 0, 0, 0, 1, 0, 0, 0, 1, -6, 0, 6)
 
-[node name="MeshInstance3D" type="MeshInstance3D" parent="TaskZone/StudyZone" unique_id=338918224]
+[node name="MeshInstance3D" type="MeshInstance3D" parent="ActivityMarkers/StudyZone" unique_id=338918224]
 transform = Transform3D(3.279775, 0, 0, 0, 5.511466, 0, 0, 0, 1, 0, 2.8180213, 0)
 mesh = SubResource("BoxMesh_kek77")
 metadata/_edit_group_ = true
 
-[node name="RestZone" type="Marker3D" parent="TaskZone" unique_id=1187838016]
+[node name="RestZone" type="Marker3D" parent="ActivityMarkers" unique_id=1187838016]
 transform = Transform3D(1, 0, 0, 0, 1, 0, 0, 0, 1, 4, 0, 5)
 
-[node name="MeshInstance3D" type="MeshInstance3D" parent="TaskZone/RestZone" unique_id=299533907]
+[node name="MeshInstance3D" type="MeshInstance3D" parent="ActivityMarkers/RestZone" unique_id=299533907]
 transform = Transform3D(1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 2.4911091, 0)
 mesh = SubResource("PrismMesh_5vw27")
 
-[node name="MeshInstance3D2" type="MeshInstance3D" parent="TaskZone/RestZone" unique_id=943692640]
+[node name="MeshInstance3D2" type="MeshInstance3D" parent="ActivityMarkers/RestZone" unique_id=943692640]
 transform = Transform3D(1, 0, 0, 0, 1, 0, 0, 0, 1, 1.3897309, 1.399735, 1.0352364)
 mesh = SubResource("PrismMesh_5vw27")
 
-[node name="FoodZone" type="Marker3D" parent="TaskZone" unique_id=780921054]
+[node name="FoodZone" type="Marker3D" parent="ActivityMarkers" unique_id=780921054]
 transform = Transform3D(1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, -8)
 
-[node name="MeshInstance3D" type="MeshInstance3D" parent="TaskZone/FoodZone" unique_id=357423915]
+[node name="MeshInstance3D" type="MeshInstance3D" parent="ActivityMarkers/FoodZone" unique_id=357423915]
 transform = Transform3D(4, 0, 0, 0, 3, 0, 0, 0, 4, 0, 1.5, 0)
 mesh = SubResource("BoxMesh_4c57u")
 

simulation/SimNPC.gd

@@ -1,8 +1,6 @@
 class_name SimNPC
 extends RefCounted
 
-const DEBUG_LOGS := true
-
 const TASK_STATE_IDLE := "idle"
 const TASK_STATE_TRAVELING := "traveling"
 const TASK_STATE_WORKING := "working"
@@ -29,22 +27,33 @@ var task_progress := 0.0
 var task_complete := true
 var target_id: StringName = &""
 var last_task := ""
+var random_source: RandomNumberGenerator
+var debug_logs := true
 
 func _init(
 	_id: int,
 	_npc_name: String,
 	_profession: String,
 	_strength: float,
-	_intelligence: float
+	_intelligence: float,
+	_random_source: RandomNumberGenerator = null
 ) -> void:
 	id = _id
 	npc_name = _npc_name
 	profession = _profession
 	strength = _strength
 	intelligence = _intelligence
-	hunger = randf_range(20.0, 80.0)
+	random_source = _random_source
-	energy = randf_range(40.0, 100.0)
+	if random_source == null:
-	position = Vector3(randf_range(-8.0, 8.0), 0.0, randf_range(-8.0, 8.0))
+		random_source = RandomNumberGenerator.new()
+		random_source.seed = id + 1
+	hunger = random_source.randf_range(20.0, 80.0)
+	energy = random_source.randf_range(40.0, 100.0)
+	position = Vector3(
+		random_source.randf_range(-8.0, 8.0),
+		0.0,
+		random_source.randf_range(-8.0, 8.0)
+	)
 
 func simulate_tick(village: SimVillage) -> void:
 	if is_dead:
@@ -104,7 +113,7 @@ func die_from_starvation() -> void:
 	task_duration = 0.0
 	task_complete = true
 
-	if DEBUG_LOGS:
+	if debug_logs:
 		print("[SimNPC] ", npc_name, " died from starvation.")
 		
 func choose_new_task(village: SimVillage) -> void:
@@ -231,9 +240,9 @@ func calculate_task_score(
 	if task_name == last_task:
 		score -= 1.5
 
-	score += randf_range(0.0, 0.5)
+	score += random_source.randf_range(0.0, 0.5)
 
-	if DEBUG_LOGS:
+	if debug_logs:
 		print(
 			"[SimNPC] ",
 			npc_name,

simulation/SimVillage.gd

@@ -1,12 +1,11 @@
 class_name SimVillage
 extends RefCounted
 
-const DEBUG_LOGS := true
-
 var food := 20.0
 var wood := 10.0
 var safety := 50.0
 var knowledge := 0.0
+var debug_logs := true
 
 var food_modifier := 1.0
 var wood_modifier := 1.0
@@ -66,7 +65,7 @@ func update_priorities() -> void:
 	elif knowledge < 15.0:
 		knowledge_priority = 1.25
 
-	if DEBUG_LOGS:
+	if debug_logs:
 		print(get_priority_summary())
 
 func apply_resource_delta(resource_id: StringName, amount: float) -> void:
@@ -160,5 +159,5 @@ func get_priority_summary() -> String:
 	]
 
 func debug_log(message: String) -> void:
-	if DEBUG_LOGS:
+	if debug_logs:
 		print("[Village] ", message)

simulation/SimulationClock.gd

@@ -0,0 +1,22 @@
+class_name SimulationClock
+extends RefCounted
+
+var tick_interval: float
+var accumulator := 0.0
+var elapsed_ticks := 0
+
+func _init(interval: float = 1.0) -> void:
+	tick_interval = maxf(interval, 0.0001)
+
+func advance(delta: float) -> int:
+	accumulator += maxf(delta, 0.0)
+	var ticks_due := 0
+	while accumulator >= tick_interval:
+		accumulator -= tick_interval
+		elapsed_ticks += 1
+		ticks_due += 1
+	return ticks_due
+
+func reset() -> void:
+	accumulator = 0.0
+	elapsed_ticks = 0

simulation/SimulationClock.gd.uid

@@ -0,0 +1 @@
+uid://ctbje7tpajoq1

simulation/SimulationManager.gd

@@ -6,12 +6,14 @@ signal npc_died(npc: SimNPC)
 
 var village := SimVillage.new()
 
-const DEBUG_LOGS := true
-
 var npcs: Array[SimNPC] = []
-var tick_interval := 1.2
+@export var tick_interval := 1.2
-var tick_timer := 0.0
+@export var simulation_seed: int = 1337
+@export var debug_logs := true
+
+var clock: SimulationClock
 var tick_count := 0
+var wander_random_sources := {}
 
 var names := [
 	"Amina", "Tarik", "Jasmin"
@@ -26,34 +28,56 @@ var professions := [
 ]
 
 func _ready() -> void:
-	randomize()
+	clock = SimulationClock.new(tick_interval)
+	village.debug_logs = debug_logs
 	village.update_modifiers()
 	village.update_priorities()
 	generate_npcs()
-	print("--- Simulation started ---")
+	if debug_logs:
+		print("--- Simulation started ---")
 	
 func _process(delta: float) -> void:
-	tick_timer += delta
+	var ticks_due := clock.advance(delta)
-
+	for tick in ticks_due:
-	if tick_timer >= tick_interval:
-		tick_timer -= tick_interval
 		simulate_tick()
 
 func generate_npcs() -> void:
 	for i in range(names.size()):
+		var npc_random := _create_random_source(i, 0)
+		var profession_index := npc_random.randi_range(0, professions.size() - 1)
 		var npc := SimNPC.new(
 			i,
 			names[i],
-			professions.pick_random(),
+			professions[profession_index],
-			randf_range(1.0, 10.0),
+			npc_random.randf_range(1.0, 10.0),
-			randf_range(1.0, 10.0)
+			npc_random.randf_range(1.0, 10.0),
+			npc_random
 		)
 
+		npc.debug_logs = debug_logs
 		npcs.append(npc)
+		wander_random_sources[i] = _create_random_source(i, 1)
+
+func _create_random_source(npc_id: int, stream_id: int) -> RandomNumberGenerator:
+	var source := RandomNumberGenerator.new()
+	source.seed = simulation_seed + (npc_id + 1) * 1000003 + stream_id * 7919
+	return source
+
+func get_wander_offset(npc_id: int) -> Vector3:
+	var source: RandomNumberGenerator = wander_random_sources.get(npc_id)
+	if source == null:
+		source = _create_random_source(npc_id, 1)
+		wander_random_sources[npc_id] = source
+	return Vector3(
+		source.randf_range(-6.0, 6.0),
+		0.0,
+		source.randf_range(-6.0, 6.0)
+	)
 
 func simulate_tick() -> void:
 	tick_count += 1
-	print("--- Tick ", tick_count, " ---")
+	if debug_logs:
+		print("--- Tick ", tick_count, " ---")
 
 	var village_was_changed := false
 
@@ -75,7 +99,7 @@ func simulate_tick() -> void:
 			npc_died.emit(npc)
 			npc_task_changed.emit(npc, old_task, npc.current_task)
 
-			if DEBUG_LOGS:
+			if debug_logs:
 				print("[SimulationManager] NPC died: ", npc.npc_name)
 
 		if old_task != npc.current_task and not npc.is_dead:
@@ -91,14 +115,14 @@ func simulate_tick() -> void:
 					var extracted := node.extract()
 					if extracted > 0:
 						village.apply_resource_delta(node.resource_id, extracted)
-						if DEBUG_LOGS:
+						if debug_logs:
 							print("[SimulationManager] ", npc.npc_name, " extracted ", extracted, " ", node.resource_id, " from ", node.node_id)
-				elif DEBUG_LOGS:
+				elif debug_logs:
 					print("[SimulationManager] ", npc.npc_name, " could not complete ", completed_task, ": target reservation was invalid")
 				release_npc_reservation(npc.id)
 			elif completed_task not in ["gather_food", "gather_wood"]:
 				village.apply_npc_task(npc)
-			elif DEBUG_LOGS:
+			elif debug_logs:
 				print("[SimulationManager] ", npc.npc_name, " could not complete ", completed_task, ": no resource target")
 
 			village_was_changed = true
@@ -112,10 +136,10 @@ func simulate_tick() -> void:
 				npc.set_task("eat", 1.0)
 				npc_task_changed.emit(npc, completed_task, npc.current_task)
 
-				if DEBUG_LOGS:
+				if debug_logs:
 					print("[SimulationManager] ", npc.npc_name, " gathered food while starving and is going to eat immediately.")
 
-		if DEBUG_LOGS:
+		if debug_logs:
 			print(
 				npc.npc_name,
 				" | ",
@@ -148,7 +172,7 @@ func simulate_tick() -> void:
 	if village_was_changed:
 		village_changed.emit(village)
 
-	if DEBUG_LOGS:
+	if debug_logs:
 		print(village.get_summary())
 		
 func set_npc_target_id(npc_id: int, target_id: StringName) -> void:
@@ -177,14 +201,14 @@ func notify_npc_arrived(npc_id: int) -> void:
 				if npc.target_id != &"":
 					var node := ResourceNode.get_by_id(npc.target_id)
 					if node == null or not node.can_extract():
-						if DEBUG_LOGS:
+						if debug_logs:
 							print("[SimulationManager] ", npc.npc_name, " arrived but target ", npc.target_id, " is unavailable, replanning")
 						notify_npc_navigation_failed(npc.id)
 						return
 
 				npc.start_working()
 
-				if DEBUG_LOGS:
+				if debug_logs:
 					print("[SimulationManager] ", npc.npc_name, " arrived and started working on: ", npc.current_task)
 			return
 
@@ -201,7 +225,7 @@ func notify_npc_navigation_failed(npc_id: int) -> void:
 		npc.set_task("wander", 2.0)
 		npc_task_changed.emit(npc, failed_task, npc.current_task)
 
-		if DEBUG_LOGS:
+		if debug_logs:
 			print("[SimulationManager] ", npc.npc_name, " could not navigate for ", failed_task, " and is trying a wander target")
 		return
 
@@ -219,7 +243,7 @@ func harvest_resource_node(node: ResourceNode) -> float:
 	village.apply_resource_delta(node.resource_id, extracted)
 	village_changed.emit(village)
 
-	if DEBUG_LOGS:
+	if debug_logs:
 		print("[SimulationManager] Player extracted ", extracted, " ", node.resource_id, " from ", node.node_id)
 
 	return extracted
@@ -250,3 +274,39 @@ func get_starving_count() -> int:
 		if npc.is_starving:
 			count += 1
 	return count
+
+func get_state_snapshot() -> Dictionary:
+	var npc_snapshots: Array[Dictionary] = []
+	for npc in npcs:
+		npc_snapshots.append({
+			"id": npc.id,
+			"name": npc.npc_name,
+			"profession": npc.profession,
+			"hunger": npc.hunger,
+			"energy": npc.energy,
+			"strength": npc.strength,
+			"intelligence": npc.intelligence,
+			"task": npc.current_task,
+			"task_state": npc.task_state,
+			"task_duration": npc.task_duration,
+			"task_progress": npc.task_progress,
+			"target_id": String(npc.target_id),
+			"position": [npc.position.x, npc.position.y, npc.position.z],
+			"starvation_ticks": npc.starvation_ticks,
+			"is_dead": npc.is_dead
+		})
+
+	return {
+		"seed": simulation_seed,
+		"tick_count": tick_count,
+		"village": {
+			"food": village.food,
+			"wood": village.wood,
+			"safety": village.safety,
+			"knowledge": village.knowledge
+		},
+		"npcs": npc_snapshots
+	}
+
+func get_state_checksum() -> String:
+	return JSON.stringify(get_state_snapshot()).sha256_text()

tests/deterministic_simulation_test.gd

@@ -0,0 +1,52 @@
+extends SceneTree
+
+var failures: Array[String] = []
+
+func _initialize() -> void:
+	call_deferred("_run")
+
+func _run() -> void:
+	var clock := SimulationClock.new(1.0)
+	_check(clock.advance(0.4) == 0, "Clock should not tick before its interval")
+	_check(clock.advance(0.6) == 1, "Clock should emit one tick at its interval")
+	_check(clock.advance(2.4) == 2, "Clock should preserve remainder across multiple ticks")
+	_check(clock.elapsed_ticks == 3, "Clock should track elapsed simulation ticks")
+
+	var first := _run_scenario(424242)
+	var second := _run_scenario(424242)
+	var different := _run_scenario(424243)
+
+	_check(first == second, "The same seed and commands should produce the same checksum")
+	_check(first != different, "A different seed should change the scenario checksum")
+
+	if failures.is_empty():
+		print("[TEST] Deterministic simulation passed | checksum=", first)
+		quit(0)
+		return
+
+	for failure in failures:
+		push_error("[TEST] " + failure)
+	quit(1)
+
+func _run_scenario(seed_value: int) -> String:
+	var manager: Node = load("res://simulation/SimulationManager.gd").new()
+	manager.simulation_seed = seed_value
+	manager.debug_logs = false
+	root.add_child(manager)
+	manager.set_process(false)
+
+	for step in 24:
+		manager.simulate_tick()
+		for npc in manager.npcs:
+			if npc.task_state == SimNPC.TASK_STATE_TRAVELING:
+				manager.notify_npc_arrived(npc.id)
+
+	var snapshot: Dictionary = manager.get_state_snapshot()
+	snapshot.erase("seed")
+	var checksum := JSON.stringify(snapshot).sha256_text()
+	manager.free()
+	return checksum
+
+func _check(condition: bool, message: String) -> void:
+	if not condition:
+		failures.append(message)

tests/deterministic_simulation_test.gd.uid

@@ -0,0 +1 @@
+uid://bexyksljoddd0

tests/flat_map_baseline_test.gd

@@ -28,10 +28,10 @@ func _run() -> void:
 	]
 	var destinations: Array[Vector3] = []
 	for marker_path in [
-		"TaskZone/FoodZone",
+		"ActivityMarkers/FoodZone",
-		"TaskZone/GuardZone",
+		"ActivityMarkers/GuardZone",
-		"TaskZone/StudyZone",
+		"ActivityMarkers/StudyZone",
-		"TaskZone/RestZone"
+		"ActivityMarkers/RestZone"
 	]:
 		destinations.append(main_scene.get_node(marker_path).global_position)
 

world/world_view_manager.gd

@@ -6,8 +6,6 @@ const DEBUG_LOGS := true
 @export var simulation_manager: Node
 @export var active_npcs_parent: Node3D
 
-@export var farm_zone: Marker3D
-@export var forest_zone: Marker3D
 @export var guard_zone: Marker3D
 @export var study_zone: Marker3D
 @export var rest_zone: Marker3D
@@ -98,7 +96,7 @@ func update_npc_targets() -> void:
 			continue
 
 		if task == "wander":
-			var offset = Vector3(randf_range(-6.0, 6.0), 0.0, randf_range(-6.0, 6.0))
+			var offset := _get_wander_offset(npc.id)
 			visual.set_target_position(visual.global_position + offset)
 			continue
 
@@ -117,10 +115,6 @@ func update_npc_targets() -> void:
 
 func get_target_for_task(task: String) -> Marker3D:
 	match task:
-		"gather_food":
-			return farm_zone
-		"gather_wood":
-			return forest_zone
 		"patrol":
 			return guard_zone
 		"study":
@@ -175,7 +169,7 @@ func _on_npc_task_changed(npc: SimNPC, old_task: String, new_task: String) -> vo
 		return
 	
 	if new_task == "wander":
-		var offset := Vector3(randf_range(-6.0, 6.0), 0.0, randf_range(-6.0, 6.0))
+		var offset := _get_wander_offset(npc.id)
 		visual.set_target_position(visual.global_position + offset)
 		return
 	
@@ -190,6 +184,12 @@ func _on_npc_task_changed(npc: SimNPC, old_task: String, new_task: String) -> vo
 	
 	if target != null:
 		visual.set_target_position(target.global_position)
+
+func _get_wander_offset(npc_id: int) -> Vector3:
+	if simulation_manager != null and simulation_manager.has_method("get_wander_offset"):
+		return simulation_manager.get_wander_offset(npc_id)
+	push_error("WorldViewManager: SimulationManager cannot provide deterministic wander offsets")
+	return Vector3.ZERO
 		
 func _on_npc_visual_arrived(sim_id: int) -> void:
 	debug_log("NPC visual arrived. sim_id=%s" % sim_id)