Add seasonal tree palettes

2026-09-02 17:20:25 -04:00 · 2026-09-02 17:20:25 -04:00 · 23cf53fa14
commit 23cf53fa14
parent 1163cef320
35 changed files with 861 additions and 43 deletions
--- a/main/main.gd
+++ b/main/main.gd
@ -108,6 +108,7 @@ const NetworkProfileServiceType = preload(
 	"res://network/network_profile_service.gd"
 )
 const WorldTimeServiceType = preload("res://world/world_time_service.gd")
+const CalendarSeasonType = preload("res://world/calendar_season.gd")
 const WorldTimeVisualControllerType = preload(
 	"res://world/world_time_visual_controller.gd"
 )
@ -406,6 +407,20 @@ func _on_world_weather_changed(
 	_apply_weather_visual_motion(weather)


+func _on_world_calendar_date_changed(_date_id: String) -> void:
+	_apply_world_calendar_season()
+
+
+func _apply_world_calendar_season() -> void:
+	var season: int = _world_time.get_season()
+	if season == CalendarSeasonType.UNKNOWN:
+		var system_date: Dictionary = Time.get_date_dict_from_system()
+		season = CalendarSeasonType.from_month(
+			int(system_date.get("month", 0))
+		)
+	_test_world.set_calendar_season(season)
+
+
 func _apply_weather_visual_motion(
 	weather: WorldWeatherService.Weather,
 ) -> void:
@ -659,6 +674,13 @@ func _initialize_application(dedicated: bool) -> void:
 	if _application_initialized:
 		return
 	_application_initialized = true
+	if not _world_time.calendar_date_changed.is_connected(
+		_on_world_calendar_date_changed
+	):
+		_world_time.calendar_date_changed.connect(
+			_on_world_calendar_date_changed
+		)
+	_apply_world_calendar_season()
 	_player.global_transform = _test_world.get_player_spawn_transform()
 	_player.velocity = Vector3.ZERO
 	_player_spawn_service.setup(
--- a/tests/generated_world_runtime_validation.gd
+++ b/tests/generated_world_runtime_validation.gd
@ -21,12 +21,16 @@ const Gatherables: GatherableCatalog = preload(
 const PrecipitationOcclusionType = preload(
 	"res://world/environment/precipitation_occlusion.gd"
 )
+const CalendarSeasonType = preload("res://world/calendar_season.gd")
 const FOLIAGE_WIND_SHADER: Shader = preload(
 	"res://world/materials/foliage_wind.gdshader"
 )
 const FOLIAGE_WIND_SOURCE_MATERIALS_META: StringName = (
 	&"foliage_wind_source_materials"
 )
+const PROP_PRIMARY_MATERIAL_ROLL_META: StringName = (
+	&"terrain_prop_primary_material_roll"
+)
 const FIRST_SEED := 13001
 const SECOND_SEED := 13002
 const RIVER_FALLBACK_SEED := 13012
@ -81,6 +85,7 @@ func _run() -> void:
 	configured_generator.elevated_cliff_third_tier_base_chance = 0.0
 	configured_generator.elevated_cliff_third_tier_stack_chance = 1.0
 	configured_generator.elevated_cliff_double_third_tier_chance = 0.0
+	region.set_calendar_season(CalendarSeasonType.Season.FALL)
 	root.add_child(region)
 	await process_frame
 	assert(region.generate_world(FIRST_SEED))
@ -757,24 +762,23 @@ func _validate_generated_region(
 				float(child.get_meta(&"terrain_prop_visual_scale", 1.0))
 			)
 			tree_yaws[snappedf((child as Node3D).rotation.y, 0.01)] = true
-		if prop_id in [
-			&"prop_tree_1",
-			&"prop_tree_2",
-			&"prop_tree_3",
-			&"prop_tree_large",
-		]:
+		if not definition.variant_material_slot_names.is_empty():
 			assert(
 				_has_material_variant_override(
 					child.get_node_or_null("Visual"),
-					definition.material_variants,
+					definition.primary_material_variants_for_season(
+						CalendarSeasonType.Season.FALL
+					),
 				)
 			)
+		if not definition.secondary_material_variants.is_empty():
 			assert(
 				_has_material_variant_override(
 					child.get_node_or_null("Visual"),
 					definition.secondary_material_variants,
 				)
 			)
+	_validate_seasonal_foliage_switch(region, decorations)
 	assert(not palm_clusters.is_empty())
 	for members: Array in palm_clusters.values():
 		assert(members.size() >= 1 and members.size() <= 3)
@ -1169,17 +1173,33 @@ func _validate_prop_catalog(region: GeneratedWorldRegion) -> void:
 		assert(tree.minimum_visual_scale < tree.maximum_visual_scale)
 		assert(tree.material_variants.size() >= 3)
 		assert(not tree.variant_material_slot_names.is_empty())
+		assert(tree.summer_material_variants.size() == 3)
+		assert(tree.fall_material_variants.size() == 4)
+		assert(
+			tree.primary_material_variants_for_season(
+				CalendarSeasonType.Season.SPRING
+			) == tree.summer_material_variants
+		)
+		assert(
+			tree.primary_material_variants_for_season(
+				CalendarSeasonType.Season.WINTER
+			) == tree.summer_material_variants
+		)
 		assert(tree.secondary_material_variants.size() >= 3)
 		assert(not tree.secondary_variant_material_slot_names.is_empty())
 	var pine := catalog.definition_for_id(&"prop_pine")
 	assert(pine != null)
 	assert(pine.minimum_visual_scale < pine.maximum_visual_scale)
 	assert(pine.material_variants.is_empty())
+	assert(pine.summer_material_variants.size() == 1)
+	assert(pine.fall_material_variants.size() == 1)
 	assert(not pine.has_gatherable_surface())
 	var large_pine := catalog.definition_for_id(&"prop_pine_large")
 	assert(large_pine != null)
 	assert(large_pine.minimum_visual_scale < large_pine.maximum_visual_scale)
 	assert(large_pine.material_variants.is_empty())
+	assert(large_pine.summer_material_variants.size() == 1)
+	assert(large_pine.fall_material_variants.size() == 1)
 	assert(not large_pine.has_gatherable_surface())
 	var palm := catalog.definition_for_id(&"prop_palm")
 	assert(palm != null)
@ -1189,6 +1209,8 @@ func _validate_prop_catalog(region: GeneratedWorldRegion) -> void:
 	assert(palm.maximum_cluster_size == 3)
 	assert(palm.minimum_cluster_radius > palm.clearance_radius)
 	assert(palm.maximum_cluster_radius > palm.minimum_cluster_radius)
+	assert(palm.summer_material_variants.size() == 1)
+	assert(palm.fall_material_variants.size() == 1)
 	assert(palm.prefer_ocean_facing)
 	assert(not palm.local_overhang_direction.is_zero_approx())
 	var aligned_tree_collisions: Dictionary[StringName, Vector2] = {
@ -1594,6 +1616,82 @@ func _find_mesh_instance(root_node: Node) -> MeshInstance3D:
 	return null


+func _validate_seasonal_foliage_switch(
+	region: GeneratedWorldRegion,
+	decorations: Node3D,
+) -> void:
+	var original_signature := _decoration_signature(region)
+	var expected_rolls: Dictionary[String, float] = {}
+	var found_broadleaf := false
+	var found_pine := false
+	var found_palm := false
+	for prop_node: Node in decorations.get_children():
+		var fall_prop := prop_node as Node3D
+		var prop_id := StringName(fall_prop.get_meta(&"terrain_prop_id", &""))
+		var fall_definition := region.get_prop_catalog().definition_for_id(prop_id)
+		if (
+			fall_definition == null
+			or fall_definition.variant_material_slot_names.is_empty()
+		):
+			continue
+		assert(fall_prop.has_meta(PROP_PRIMARY_MATERIAL_ROLL_META))
+		var roll := float(fall_prop.get_meta(PROP_PRIMARY_MATERIAL_ROLL_META))
+		assert(roll >= 0.0 and roll < 1.0)
+		expected_rolls[fall_prop.name] = roll
+		assert(_has_material_variant_override(
+			fall_prop.get_node_or_null("Visual"),
+			fall_definition.primary_material_variants_for_season(
+				CalendarSeasonType.Season.FALL
+			),
+		))
+		found_broadleaf = found_broadleaf or String(prop_id).begins_with(
+			"prop_tree_"
+		)
+		found_pine = found_pine or prop_id in [
+			&"prop_pine",
+			&"prop_pine_large",
+		]
+		found_palm = found_palm or prop_id == &"prop_palm"
+	assert(found_broadleaf and found_pine and found_palm)
+
+	region.set_calendar_season(CalendarSeasonType.Season.SUMMER)
+	assert(_decoration_signature(region) == original_signature)
+	for prop_node: Node in decorations.get_children():
+		var summer_prop := prop_node as Node3D
+		if not expected_rolls.has(summer_prop.name):
+			continue
+		assert(is_equal_approx(
+			float(summer_prop.get_meta(PROP_PRIMARY_MATERIAL_ROLL_META)),
+			expected_rolls[summer_prop.name],
+		))
+		var summer_definition := region.get_prop_catalog().definition_for_id(
+			StringName(summer_prop.get_meta(&"terrain_prop_id", &""))
+		)
+		assert(_has_material_variant_override(
+			summer_prop.get_node_or_null("Visual"),
+			summer_definition.primary_material_variants_for_season(
+				CalendarSeasonType.Season.SUMMER
+			),
+		))
+	assert(_first_foliage_wind_material(decorations) != null)
+
+	region.set_calendar_season(CalendarSeasonType.Season.FALL)
+	assert(_decoration_signature(region) == original_signature)
+	for prop_node: Node in decorations.get_children():
+		var restored_prop := prop_node as Node3D
+		if not expected_rolls.has(restored_prop.name):
+			continue
+		var restored_definition := region.get_prop_catalog().definition_for_id(
+			StringName(restored_prop.get_meta(&"terrain_prop_id", &""))
+		)
+		assert(_has_material_variant_override(
+			restored_prop.get_node_or_null("Visual"),
+			restored_definition.primary_material_variants_for_season(
+				CalendarSeasonType.Season.FALL
+			),
+		))
+
+
 func _first_foliage_wind_material(root_node: Node) -> ShaderMaterial:
 	var mesh_instance := root_node as MeshInstance3D
 	if mesh_instance != null and mesh_instance.mesh != null:
@ -1652,8 +1750,15 @@ func _has_material_variant_override(
 					surface_index,
 					null,
 				) as Material
-				if source_material != null and source_material in variants:
-					return true
+				var source_standard := source_material as StandardMaterial3D
+				if source_standard != null and source_material in variants:
+					var visible_color: Color = wind_material.get_shader_parameter(
+						"albedo_color"
+					)
+					if visible_color.is_equal_approx(
+						source_standard.albedo_color
+					):
+						return true
 	for child: Node in root_node.get_children():
 		if _has_material_variant_override(child, variants):
 			return true
--- a/tests/terrain_seasonal_material_validation.gd
+++ b/tests/terrain_seasonal_material_validation.gd
@ -0,0 +1,274 @@
+extends SceneTree
+
+const CalendarSeasonType = preload("res://world/calendar_season.gd")
+const PropCatalog: TerrainPropCatalog = preload(
+	"res://world/generation/props/terrain_prop_catalog.tres"
+)
+const RegionScene: PackedScene = preload(
+	"res://world/generation/generated_world_region.tscn"
+)
+
+const BROADLEAF_IDS: Array[StringName] = [
+	&"prop_tree_1",
+	&"prop_tree_2",
+	&"prop_tree_3",
+	&"prop_tree_large",
+]
+const IMPORTED_FOLIAGE_NAMES: Dictionary = {
+	&"prop_tree_1": &"leaf_autumn_light",
+	&"prop_tree_2": &"leaf_autumn",
+	&"prop_tree_3": &"leaf_autumn_dark",
+	&"prop_tree_large": &"leaf_autumn_mid",
+	&"prop_pine": &"pine_summer",
+	&"prop_pine_large": &"pine_autumn",
+	&"prop_palm": &"palm_autumn",
+}
+const PROP_PRIMARY_MATERIAL_ROLL_META: StringName = (
+	&"terrain_prop_primary_material_roll"
+)
+const PROP_LEGACY_PRIMARY_MATERIAL_INDEX_META: StringName = (
+	&"terrain_prop_legacy_primary_material_index"
+)
+
+
+func _initialize() -> void:
+	call_deferred(&"_run")
+
+
+func _run() -> void:
+	assert(PropCatalog.validation_errors().is_empty())
+	for stable_id: StringName in BROADLEAF_IDS:
+		var definition := PropCatalog.definition_for_id(stable_id)
+		assert(definition != null)
+		_assert_palette(
+			definition.summer_material_variants,
+			PackedStringArray([
+				"leaf_variant_light",
+				"leaf_variant_mid",
+				"leaf_variant_dark",
+			]),
+			[
+				Color(0.3387566, 0.7186728, 0, 1),
+				Color(0.3146831, 0.4631305, 0, 1),
+				Color(0.1712407, 0.2520192, 0, 1),
+			],
+		)
+		_assert_palette(
+			definition.fall_material_variants,
+			PackedStringArray([
+				"leaf_autumn_light",
+				"leaf_autumn",
+				"leaf_autumn_mid",
+				"leaf_autumn_dark",
+			]),
+			[
+				Color(0.8222013, 0.794216, 0, 1),
+				Color(0.6186816, 0.4523746, 0, 1),
+				Color(0.6841143, 0.3515543, 0, 1),
+				Color(0.3853541, 0.00134692, 0, 1),
+			],
+		)
+		assert(
+			definition.primary_material_variants_for_season(
+				CalendarSeasonType.Season.SPRING
+			) == definition.summer_material_variants
+		)
+		assert(
+			definition.primary_material_variants_for_season(
+				CalendarSeasonType.Season.WINTER
+			) == definition.summer_material_variants
+		)
+
+	_assert_single_seasonal_tree(
+		&"prop_pine",
+		&"pine_summer",
+		Color(0.02171588, 0.2242201, 0.1360403, 1),
+		&"pine_autumn",
+		Color(0.02388079, 0.1285609, 0, 1),
+	)
+	_assert_single_seasonal_tree(
+		&"prop_pine_large",
+		&"pine_summer",
+		Color(0.02171588, 0.2242201, 0.1360403, 1),
+		&"pine_autumn",
+		Color(0.02388079, 0.1285609, 0, 1),
+	)
+	_assert_single_seasonal_tree(
+		&"prop_palm",
+		&"palm_summer",
+		Color(0.3146831, 0.4631305, 0, 1),
+		&"palm_autumn",
+		Color(0.2951757, 0.3575695, 0.162893, 1),
+	)
+
+	for stable_id: StringName in IMPORTED_FOLIAGE_NAMES:
+		var definition := PropCatalog.definition_for_id(stable_id)
+		var instance := definition.packed_scene.instantiate()
+		var material_names := PackedStringArray()
+		_collect_material_names(instance, material_names)
+		assert(IMPORTED_FOLIAGE_NAMES[stable_id] in material_names)
+		instance.free()
+
+	var region := RegionScene.instantiate() as GeneratedWorldRegion
+	assert(region != null)
+	assert(bool(region.call(
+		"_material_name_matches_targets",
+		&"leaf_autumn_mid",
+		PackedStringArray(["leaf"]),
+	)))
+	assert(bool(region.call(
+		"_material_name_matches_targets",
+		&"pine_winter",
+		PackedStringArray(["pine"]),
+	)))
+	assert(bool(region.call(
+		"_material_name_matches_targets",
+		&"palm_spring",
+		PackedStringArray(["palm"]),
+	)))
+	_validate_palette_roll_mapping(region)
+	_validate_primary_roll_random_state(region)
+	region.free()
+	print("Terrain seasonal material validation: PASS")
+	quit()
+
+
+func _assert_single_seasonal_tree(
+	stable_id: StringName,
+	summer_name: StringName,
+	summer_color: Color,
+	fall_name: StringName,
+	fall_color: Color,
+) -> void:
+	var definition := PropCatalog.definition_for_id(stable_id)
+	assert(definition != null)
+	_assert_palette(
+		definition.summer_material_variants,
+		PackedStringArray([summer_name]),
+		[summer_color],
+	)
+	_assert_palette(
+		definition.fall_material_variants,
+		PackedStringArray([fall_name]),
+		[fall_color],
+	)
+
+
+func _assert_palette(
+	materials: Array[Material],
+	expected_names: PackedStringArray,
+	expected_colors: Array[Color],
+) -> void:
+	assert(materials.size() == expected_names.size())
+	assert(materials.size() == expected_colors.size())
+	for index: int in materials.size():
+		var material := materials[index] as StandardMaterial3D
+		assert(material != null)
+		assert(material.resource_name == expected_names[index])
+		assert(material.albedo_color.is_equal_approx(expected_colors[index]))
+
+
+func _validate_palette_roll_mapping(region: GeneratedWorldRegion) -> void:
+	var definition := PropCatalog.definition_for_id(&"prop_tree_1")
+	assert(definition != null)
+	var instance := definition.packed_scene.instantiate()
+	var palette := definition.fall_material_variants
+	for index: int in palette.size():
+		var roll := (float(index) + 0.5) / float(palette.size())
+		region.call(
+			"_apply_material_variant_for_roll",
+			instance,
+			definition.variant_material_slot_names,
+			palette,
+			roll,
+		)
+		assert(_has_surface_override(instance, palette[index]))
+	instance.free()
+
+
+func _validate_primary_roll_random_state(
+	region: GeneratedWorldRegion,
+) -> void:
+	var broadleaf := PropCatalog.definition_for_id(&"prop_tree_1")
+	var baseline := RandomNumberGenerator.new()
+	baseline.seed = 29092026
+	var actual := RandomNumberGenerator.new()
+	actual.seed = baseline.seed
+	var legacy_index := baseline.randi_range(
+		0,
+		broadleaf.material_variants.size() - 1,
+	)
+	var selection := region.call(
+		"_primary_material_selection",
+		broadleaf,
+		actual,
+	) as Dictionary
+	var roll := float(selection.get("roll", -1.0))
+	assert(roll >= 0.0 and roll < 1.0)
+	assert(int(selection.get("legacy_index", -1)) == legacy_index)
+	assert(actual.state == baseline.state)
+	var prop := Node3D.new()
+	prop.set_meta(PROP_PRIMARY_MATERIAL_ROLL_META, 0.125)
+	prop.set_meta(
+		PROP_LEGACY_PRIMARY_MATERIAL_INDEX_META,
+		legacy_index,
+	)
+	var summer_roll := float(region.call(
+		"_primary_material_roll_for_palette",
+		prop,
+		broadleaf,
+		broadleaf.summer_material_variants,
+	))
+	assert(
+		floori(summer_roll * broadleaf.summer_material_variants.size())
+		== legacy_index
+	)
+	var fall_roll := float(region.call(
+		"_primary_material_roll_for_palette",
+		prop,
+		broadleaf,
+		broadleaf.fall_material_variants,
+	))
+	assert(is_equal_approx(fall_roll, 0.125))
+	prop.free()
+
+	var pine := PropCatalog.definition_for_id(&"prop_pine")
+	var pine_random := RandomNumberGenerator.new()
+	pine_random.seed = 29092026
+	var pine_initial_state := pine_random.state
+	var pine_selection := region.call(
+		"_primary_material_selection",
+		pine,
+		pine_random,
+	) as Dictionary
+	assert(int(pine_selection.get("legacy_index", -2)) == -1)
+	assert(pine_random.state == pine_initial_state)
+
+
+func _has_surface_override(root_node: Node, expected: Material) -> bool:
+	var mesh_instance := root_node as MeshInstance3D
+	if mesh_instance != null and mesh_instance.mesh != null:
+		for surface_index: int in mesh_instance.mesh.get_surface_count():
+			if (
+				mesh_instance.get_surface_override_material(surface_index)
+				== expected
+			):
+				return true
+	for child: Node in root_node.get_children():
+		if _has_surface_override(child, expected):
+			return true
+	return false
+
+
+func _collect_material_names(
+	node: Node,
+	material_names: PackedStringArray,
+) -> void:
+	var mesh_instance := node as MeshInstance3D
+	if mesh_instance != null and mesh_instance.mesh != null:
+		for surface_index: int in mesh_instance.mesh.get_surface_count():
+			var material := mesh_instance.mesh.surface_get_material(surface_index)
+			if material != null:
+				material_names.append(material.resource_name)
+	for child: Node in node.get_children():
+		_collect_material_names(child, material_names)
--- a/tests/terrain_seasonal_material_validation.gd.uid
+++ b/tests/terrain_seasonal_material_validation.gd.uid
@ -0,0 +1 @@
+uid://dicorkv8nbkb5
--- a/tests/world_layout_validation.gd
+++ b/tests/world_layout_validation.gd
@ -4,6 +4,7 @@ const TestWorldScene: PackedScene = preload("res://world/test_world.tscn")
 const SetupPageScene: PackedScene = preload(
 	"res://ui/new_game_setup_page.tscn"
 )
+const CalendarSeasonType = preload("res://world/calendar_season.gd")


 func _initialize() -> void:
@ -84,6 +85,7 @@ func _validate_world_switching() -> void:
 	root.add_child(world)
 	await process_frame
 	assert(world.get_world_layout() == WorldLayout.GENERATED)
+	world.set_calendar_season(CalendarSeasonType.Season.FALL)
 	world.set_foliage_wind_strength_multiplier(2.0)
 	world.set_water_motion_strength_multiplier(2.0)
 	var initial_generator := world.get_node(
@ -134,6 +136,15 @@ func _validate_world_switching() -> void:
 		"Regions/GeneratedWorldRegion"
 	) as GeneratedWorldRegion
 	assert(generated_region != null)
+	assert(
+		int(generated_region.get("_calendar_season"))
+		== CalendarSeasonType.Season.FALL
+	)
+	world.set_calendar_season(CalendarSeasonType.Season.SUMMER)
+	assert(
+		int(generated_region.get("_calendar_season"))
+		== CalendarSeasonType.Season.SUMMER
+	)
 	assert(is_equal_approx(
 		float(generated_region.get("_foliage_wind_strength_multiplier")), 2.0
 	))
--- a/world/generation/generated_world_region.gd
+++ b/world/generation/generated_world_region.gd
@ -20,6 +20,7 @@ const RVUpgradeInteractionType = preload(
 const PrecipitationOcclusionType = preload(
 	"res://world/environment/precipitation_occlusion.gd"
 )
+const CalendarSeasonType = preload("res://world/calendar_season.gd")
 const FOLIAGE_WIND_SHADER: Shader = preload(
 	"res://world/materials/foliage_wind.gdshader"
 )
@ -88,7 +89,14 @@ const FOLIAGE_MATERIAL_NAMES: Array[StringName] = [
 	&"leaf_variant_light",
 	&"leaf_variant_mid",
 	&"leaf_variant_dark",
+	&"palm",
 ]
+const PROP_PRIMARY_MATERIAL_ROLL_META: StringName = (
+	&"terrain_prop_primary_material_roll"
+)
+const PROP_LEGACY_PRIMARY_MATERIAL_INDEX_META: StringName = (
+	&"terrain_prop_legacy_primary_material_index"
+)
 # Retain the exact generated material override while foliage wind is active so
 # profile changes restore both the selected palette and authored surface state.
 const FOLIAGE_WIND_SOURCE_MATERIALS_META: StringName = (
@ -138,6 +146,7 @@ var _water_recovery_triangles_by_coordinate: Dictionary[Vector2i, Array] = {}
 var _home_accessible_elevations_by_coordinate: Dictionary[Vector2i, Array] = {}
 var _foliage_wind_enabled: bool = false
 var _foliage_wind_strength_multiplier: float = 1.0
+var _calendar_season: int = CalendarSeasonType.UNKNOWN


 func _ready() -> void:
@ -148,6 +157,11 @@ func _ready() -> void:
 	_set_foliage_wind_enabled(not _light_performance_profile)


+func _exit_tree() -> void:
+	if _decorations != null:
+		_apply_foliage_wind_to_node(_decorations, false)
+
+
 func generate_world(world_seed: int) -> bool:
 	if world_seed <= 0 or world_seed > PlayerSaveManager.MAX_WORLD_SEED:
 		return false
@ -232,6 +246,18 @@ func set_water_motion_strength_multiplier(multiplier: float) -> void:
 		surface_motion.set_motion_strength_multiplier(multiplier)


+func set_calendar_season(season: int) -> void:
+	var normalized_season := (
+		season
+		if season >= 0 and season < CalendarSeasonType.Season.size()
+		else CalendarSeasonType.UNKNOWN
+	)
+	if normalized_season == _calendar_season:
+		return
+	_calendar_season = normalized_season
+	_refresh_seasonal_prop_materials()
+
+
 func _get_ocean_surface_motion() -> WaterSurfaceMotion:
 	return _ocean.get_node_or_null(^"VisualWater") as WaterSurfaceMotion

@ -319,6 +345,7 @@ func _on_generation_completed(summary: Dictionary) -> void:
 	_cache_home_accessible_elevations(records)
 	_assign_biomes(records, summary)
 	var spawn_position := Vector3.ZERO
+	_apply_foliage_wind_to_node(_decorations, false)
 	_clear_children(_decorations)
 	_clear_children(_tree_anchors)
 	_placed_prop_positions.clear()
@ -655,7 +682,7 @@ func _apply_foliage_wind_to_mesh(mesh_instance: MeshInstance3D) -> void:
 		)
 		if not source_material is StandardMaterial3D:
 			continue
-		if not FOLIAGE_MATERIAL_NAMES.has(
+		if not _is_foliage_material_name(
 			StringName(source_material.resource_name)
 		):
 			continue
@ -1156,6 +1183,18 @@ func _instantiate_prop(
 	prop.set_meta(&"terrain_prop_visual_scale", visual_scale)
 	prop.set_meta(&"terrain_prop_cluster_id", cluster_id)
 	prop.set_meta(&"terrain_prop_cluster_member_index", cluster_member_index)
+	var primary_material_selection := _primary_material_selection(
+		definition,
+		random,
+	)
+	prop.set_meta(
+		PROP_PRIMARY_MATERIAL_ROLL_META,
+		float(primary_material_selection.get("roll", 0.5)),
+	)
+	prop.set_meta(
+		PROP_LEGACY_PRIMARY_MATERIAL_INDEX_META,
+		int(primary_material_selection.get("legacy_index", -1)),
+	)
 	prop.position = placement
 	prop.rotation.y = yaw
 	_decorations.add_child(prop)
@ -1164,7 +1203,7 @@ func _instantiate_prop(
 	visual_root.position = definition.visual_offset
 	visual_root.scale = Vector3.ONE * visual_scale
 	_configure_prop_visuals(visual_root)
-	_apply_prop_material_variant(visual_root, definition, random)
+	_apply_prop_material_variants(prop, visual_root, definition, random)
 	_add_prop_collision(prop, definition, visual_scale)
 	_placed_prop_positions.append(placement)
 	_placed_prop_clearance_radii.append(
@ -1526,16 +1565,24 @@ func _configure_prop_visuals(root_node: Node) -> void:
 		_configure_prop_visuals(child)


-func _apply_prop_material_variant(
+func _apply_prop_material_variants(
+	prop: Node3D,
 	root_node: Node,
 	definition: TerrainPropDefinition,
 	random: RandomNumberGenerator,
 ) -> void:
-	_apply_random_material_variant(
+	var primary_variants := definition.primary_material_variants_for_season(
+		_calendar_season
+	)
+	_apply_material_variant_for_roll(
 		root_node,
 		definition.variant_material_slot_names,
-		definition.material_variants,
-		random,
+		primary_variants,
+		_primary_material_roll_for_palette(
+			prop,
+			definition,
+			primary_variants,
+		),
 	)
 	_apply_random_material_variant(
 		root_node,
@ -1545,6 +1592,69 @@ func _apply_prop_material_variant(
 	)


+func _primary_material_selection(
+	definition: TerrainPropDefinition,
+	random: RandomNumberGenerator,
+) -> Dictionary:
+	var preview_random := RandomNumberGenerator.new()
+	preview_random.state = random.state
+	var roll := preview_random.randf()
+	# Preserve the legacy foliage draw so this presentation-only feature never
+	# changes which props a known world seed places afterward. Retain its chosen
+	# index too, so existing summer worlds keep their exact historical tint.
+	var legacy_index := -1
+	if not definition.material_variants.is_empty():
+		legacy_index = random.randi_range(
+			0,
+			definition.material_variants.size() - 1,
+		)
+	# New seasonal-only definitions such as pine and palm peek at the current
+	# deterministic state without consuming it, preserving their old layout.
+	return {
+		"roll": roll,
+		"legacy_index": legacy_index,
+	}
+
+
+func _primary_material_roll_for_palette(
+	prop: Node3D,
+	definition: TerrainPropDefinition,
+	variants: Array[Material],
+) -> float:
+	var legacy_index := int(prop.get_meta(
+		PROP_LEGACY_PRIMARY_MATERIAL_INDEX_META,
+		-1,
+	))
+	var uses_summer_palette := (
+		not definition.summer_material_variants.is_empty()
+		and variants == definition.summer_material_variants
+	)
+	if uses_summer_palette and legacy_index >= 0:
+		var clamped_index := mini(legacy_index, variants.size() - 1)
+		return (float(clamped_index) + 0.5) / float(variants.size())
+	return float(prop.get_meta(PROP_PRIMARY_MATERIAL_ROLL_META, 0.5))
+
+
+func _apply_material_variant_for_roll(
+	root_node: Node,
+	target_material_names: PackedStringArray,
+	variants: Array[Material],
+	roll: float,
+) -> void:
+	if variants.is_empty() or target_material_names.is_empty():
+		return
+	var variant_index := mini(
+		floori(clampf(roll, 0.0, 0.999999) * float(variants.size())),
+		variants.size() - 1,
+	)
+	_apply_material_variant_to_meshes(
+		root_node,
+		target_material_names,
+		variants[variant_index],
+		true,
+	)
+
+
 func _apply_random_material_variant(
 	root_node: Node,
 	target_material_names: PackedStringArray,
@ -1558,6 +1668,7 @@ func _apply_random_material_variant(
 		root_node,
 		target_material_names,
 		variant,
+		false,
 	)


@ -1565,16 +1676,28 @@ func _apply_material_variant_to_meshes(
 	root_node: Node,
 	target_material_names: PackedStringArray,
 	variant: Material,
+	match_material_family: bool,
 ) -> void:
 	var mesh_instance := root_node as MeshInstance3D
 	if mesh_instance != null and mesh_instance.mesh != null:
 		for surface_index: int in mesh_instance.mesh.get_surface_count():
-			var active_material := mesh_instance.get_active_material(surface_index)
-			if (
-				active_material != null
-				and active_material.resource_name in target_material_names
-			):
-				mesh_instance.set_surface_override_material(
+			var source_material := mesh_instance.mesh.surface_get_material(
+				surface_index
+			)
+			var material_matches := (
+				source_material != null
+				and (
+					_material_name_matches_targets(
+						StringName(source_material.resource_name),
+						target_material_names,
+					)
+					if match_material_family
+					else source_material.resource_name in target_material_names
+				)
+			)
+			if material_matches:
+				_apply_material_variant_to_surface(
+					mesh_instance,
 					surface_index,
 					variant,
 				)
@ -1583,6 +1706,107 @@ func _apply_material_variant_to_meshes(
 			child,
 			target_material_names,
 			variant,
+			match_material_family,
+		)
+
+
+func _apply_material_variant_to_surface(
+	mesh_instance: MeshInstance3D,
+	surface_index: int,
+	variant: Material,
+) -> void:
+	var wind_material := mesh_instance.get_surface_override_material(
+		surface_index
+	) as ShaderMaterial
+	var standard_variant := variant as StandardMaterial3D
+	if (
+		wind_material != null
+		and wind_material.shader == FOLIAGE_WIND_SHADER
+	):
+		# Seasonal foliage is intentionally authored as StandardMaterial3D. Keep
+		# the current wind presentation intact if a malformed catalog entry slips
+		# through instead of silently replacing it with an incompatible shader.
+		if standard_variant == null:
+			return
+		var source_materials: Dictionary = mesh_instance.get_meta(
+			FOLIAGE_WIND_SOURCE_MATERIALS_META,
+			{},
+		)
+		source_materials[surface_index] = variant
+		mesh_instance.set_meta(
+			FOLIAGE_WIND_SOURCE_MATERIALS_META,
+			source_materials,
+		)
+		wind_material.set_shader_parameter(
+			"albedo_color",
+			standard_variant.albedo_color,
+		)
+		wind_material.set_shader_parameter(
+			"material_roughness",
+			standard_variant.roughness,
+		)
+		wind_material.set_shader_parameter(
+			"material_metallic",
+			standard_variant.metallic,
+		)
+		return
+	mesh_instance.set_surface_override_material(surface_index, variant)
+
+
+func _material_name_matches_targets(
+	material_name: StringName,
+	target_material_names: PackedStringArray,
+) -> bool:
+	var normalized_name := String(material_name).to_lower()
+	for target_name: String in target_material_names:
+		var normalized_target := target_name.to_lower()
+		if (
+			normalized_name == normalized_target
+			or normalized_name.begins_with(normalized_target + "_")
+		):
+			return true
+	return false
+
+
+func _is_foliage_material_name(material_name: StringName) -> bool:
+	var normalized_name := String(material_name).to_lower()
+	for target_name: StringName in FOLIAGE_MATERIAL_NAMES:
+		var normalized_target := String(target_name).to_lower()
+		if (
+			normalized_name == normalized_target
+			or normalized_name.begins_with(normalized_target + "_")
+		):
+			return true
+	return false
+
+
+func _refresh_seasonal_prop_materials() -> void:
+	if _decorations == null:
+		return
+	for prop_node: Node in _decorations.get_children():
+		var prop := prop_node as Node3D
+		if prop == null:
+			continue
+		var definition := prop_catalog.definition_for_id(
+			StringName(prop.get_meta(&"terrain_prop_id", &""))
+		) if prop_catalog != null else null
+		if definition == null:
+			continue
+		var visual_root := prop.get_node_or_null("Visual")
+		if visual_root == null:
+			continue
+		var primary_variants := definition.primary_material_variants_for_season(
+			_calendar_season
+		)
+		_apply_material_variant_for_roll(
+			visual_root,
+			definition.variant_material_slot_names,
+			primary_variants,
+			_primary_material_roll_for_palette(
+				prop,
+				definition,
+				primary_variants,
+			),
 		)


--- a/world/generation/props/assets/prop_palm.glb
+++ b/world/generation/props/assets/prop_palm.glb
--- a/world/generation/props/assets/prop_pine.glb
+++ b/world/generation/props/assets/prop_pine.glb
--- a/world/generation/props/assets/prop_pine_large.glb
+++ b/world/generation/props/assets/prop_pine_large.glb
--- a/world/generation/props/assets/prop_tree_1.glb
+++ b/world/generation/props/assets/prop_tree_1.glb
--- a/world/generation/props/assets/prop_tree_2.glb
+++ b/world/generation/props/assets/prop_tree_2.glb
--- a/world/generation/props/assets/prop_tree_3.glb
+++ b/world/generation/props/assets/prop_tree_3.glb
--- a/world/generation/props/assets/prop_tree_large.glb
+++ b/world/generation/props/assets/prop_tree_large.glb
--- a/world/generation/props/definitions/prop_palm.tres
+++ b/world/generation/props/definitions/prop_palm.tres
@ -1,7 +1,9 @@
-[gd_resource type="Resource" script_class="TerrainPropDefinition" load_steps=3 format=3]
+[gd_resource type="Resource" script_class="TerrainPropDefinition" load_steps=5 format=3]

 [ext_resource type="Script" path="res://world/generation/terrain_prop_definition.gd" id="1_definition"]
 [ext_resource type="PackedScene" path="res://world/generation/props/assets/prop_palm.glb" id="2_scene"]
+[ext_resource type="Material" path="res://world/generation/props/materials/palm_summer.tres" id="3_palm_summer"]
+[ext_resource type="Material" path="res://world/generation/props/materials/palm_autumn.tres" id="4_palm_autumn"]

 [resource]
 script = ExtResource("1_definition")
@ -18,6 +20,9 @@ minimum_cluster_size = 2
 maximum_cluster_size = 3
 minimum_cluster_radius = 1.4
 maximum_cluster_radius = 3.0
+variant_material_slot_names = PackedStringArray("leaf", "palm")
+summer_material_variants = Array[Material]([ExtResource("3_palm_summer")])
+fall_material_variants = Array[Material]([ExtResource("4_palm_autumn")])
 prefer_ocean_facing = true
 local_overhang_direction = Vector2(-0.883, 0.469)
 ocean_facing_spread_degrees = 55.0
--- a/world/generation/props/definitions/prop_pine.tres
+++ b/world/generation/props/definitions/prop_pine.tres
@ -1,7 +1,9 @@
-[gd_resource type="Resource" script_class="TerrainPropDefinition" load_steps=3 format=3]
+[gd_resource type="Resource" script_class="TerrainPropDefinition" load_steps=5 format=3]

 [ext_resource type="Script" path="res://world/generation/terrain_prop_definition.gd" id="1_definition"]
 [ext_resource type="PackedScene" path="res://world/generation/props/assets/prop_pine.glb" id="2_scene"]
+[ext_resource type="Material" path="res://world/generation/props/materials/pine_summer.tres" id="3_pine_summer"]
+[ext_resource type="Material" path="res://world/generation/props/materials/pine_autumn.tres" id="4_pine_autumn"]

 [resource]
 script = ExtResource("1_definition")
@ -15,6 +17,9 @@ minimum_spawn_chunk_distance = 2
 clearance_radius = 1.55
 minimum_visual_scale = 0.65
 maximum_visual_scale = 1.2
+variant_material_slot_names = PackedStringArray("pine")
+summer_material_variants = Array[Material]([ExtResource("3_pine_summer")])
+fall_material_variants = Array[Material]([ExtResource("4_pine_autumn")])
 collision_radius = 0.85
 collision_height = 4.0
 collision_offset = Vector3(-0.044, 0, 0.083)
--- a/world/generation/props/definitions/prop_pine_large.tres
+++ b/world/generation/props/definitions/prop_pine_large.tres
@ -1,7 +1,9 @@
-[gd_resource type="Resource" script_class="TerrainPropDefinition" load_steps=3 format=3]
+[gd_resource type="Resource" script_class="TerrainPropDefinition" load_steps=5 format=3]

 [ext_resource type="Script" path="res://world/generation/terrain_prop_definition.gd" id="1_definition"]
 [ext_resource type="PackedScene" path="res://world/generation/props/assets/prop_pine_large.glb" id="2_scene"]
+[ext_resource type="Material" path="res://world/generation/props/materials/pine_summer.tres" id="3_pine_summer"]
+[ext_resource type="Material" path="res://world/generation/props/materials/pine_autumn.tres" id="4_pine_autumn"]

 [resource]
 script = ExtResource("1_definition")
@ -15,6 +17,9 @@ minimum_spawn_chunk_distance = 2
 clearance_radius = 1.65
 minimum_visual_scale = 0.75
 maximum_visual_scale = 1.2
+variant_material_slot_names = PackedStringArray("pine")
+summer_material_variants = Array[Material]([ExtResource("3_pine_summer")])
+fall_material_variants = Array[Material]([ExtResource("4_pine_autumn")])
 collision_radius = 0.75
 collision_height = 9.5
 collision_offset = Vector3(-0.04, 0, 0.075)
--- a/world/generation/props/definitions/prop_tree_1.tres
+++ b/world/generation/props/definitions/prop_tree_1.tres
@ -1,4 +1,4 @@
-[gd_resource type="Resource" script_class="TerrainPropDefinition" load_steps=9 format=3]
+[gd_resource type="Resource" script_class="TerrainPropDefinition" load_steps=13 format=3]

 [ext_resource type="Script" path="res://world/generation/terrain_prop_definition.gd" id="1_definition"]
 [ext_resource type="PackedScene" path="res://world/generation/props/assets/prop_tree_1.glb" id="2_scene"]
@ -8,6 +8,10 @@
 [ext_resource type="Material" path="res://world/generation/props/materials/wood_light.tres" id="6_wood_light"]
 [ext_resource type="Material" path="res://world/generation/props/materials/wood_mid.tres" id="7_wood_mid"]
 [ext_resource type="Material" path="res://world/generation/props/materials/wood_dark.tres" id="8_wood_dark"]
+[ext_resource type="Material" path="res://world/generation/props/materials/leaf_autumn_light.tres" id="9_leaf_autumn_light"]
+[ext_resource type="Material" path="res://world/generation/props/materials/leaf_autumn.tres" id="10_leaf_autumn"]
+[ext_resource type="Material" path="res://world/generation/props/materials/leaf_autumn_mid.tres" id="11_leaf_autumn_mid"]
+[ext_resource type="Material" path="res://world/generation/props/materials/leaf_autumn_dark.tres" id="12_leaf_autumn_dark"]

 [resource]
 script = ExtResource("1_definition")
@ -21,8 +25,10 @@ minimum_spawn_chunk_distance = 2
 clearance_radius = 1.3
 minimum_visual_scale = 0.65
 maximum_visual_scale = 1.2
-variant_material_slot_names = PackedStringArray("leaf_light", "leaf", "leaf_dark")
+variant_material_slot_names = PackedStringArray("leaf")
 material_variants = Array[Material]([ExtResource("3_leaf_light"), ExtResource("4_leaf_mid"), ExtResource("5_leaf_dark")])
+summer_material_variants = Array[Material]([ExtResource("3_leaf_light"), ExtResource("4_leaf_mid"), ExtResource("5_leaf_dark")])
+fall_material_variants = Array[Material]([ExtResource("9_leaf_autumn_light"), ExtResource("10_leaf_autumn"), ExtResource("11_leaf_autumn_mid"), ExtResource("12_leaf_autumn_dark")])
 secondary_variant_material_slot_names = PackedStringArray("wood", "wood_light", "wood_mid")
 secondary_material_variants = Array[Material]([ExtResource("6_wood_light"), ExtResource("7_wood_mid"), ExtResource("8_wood_dark")])
 collision_radius = 0.4
--- a/world/generation/props/definitions/prop_tree_2.tres
+++ b/world/generation/props/definitions/prop_tree_2.tres
@ -1,4 +1,4 @@
-[gd_resource type="Resource" script_class="TerrainPropDefinition" load_steps=9 format=3]
+[gd_resource type="Resource" script_class="TerrainPropDefinition" load_steps=13 format=3]

 [ext_resource type="Script" path="res://world/generation/terrain_prop_definition.gd" id="1_definition"]
 [ext_resource type="PackedScene" path="res://world/generation/props/assets/prop_tree_2.glb" id="2_scene"]
@ -8,6 +8,10 @@
 [ext_resource type="Material" path="res://world/generation/props/materials/wood_light.tres" id="6_wood_light"]
 [ext_resource type="Material" path="res://world/generation/props/materials/wood_mid.tres" id="7_wood_mid"]
 [ext_resource type="Material" path="res://world/generation/props/materials/wood_dark.tres" id="8_wood_dark"]
+[ext_resource type="Material" path="res://world/generation/props/materials/leaf_autumn_light.tres" id="9_leaf_autumn_light"]
+[ext_resource type="Material" path="res://world/generation/props/materials/leaf_autumn.tres" id="10_leaf_autumn"]
+[ext_resource type="Material" path="res://world/generation/props/materials/leaf_autumn_mid.tres" id="11_leaf_autumn_mid"]
+[ext_resource type="Material" path="res://world/generation/props/materials/leaf_autumn_dark.tres" id="12_leaf_autumn_dark"]

 [resource]
 script = ExtResource("1_definition")
@ -21,8 +25,10 @@ minimum_spawn_chunk_distance = 2
 clearance_radius = 1.5
 minimum_visual_scale = 0.7
 maximum_visual_scale = 1.2
-variant_material_slot_names = PackedStringArray("leaf_light", "leaf", "leaf_dark")
+variant_material_slot_names = PackedStringArray("leaf")
 material_variants = Array[Material]([ExtResource("3_leaf_light"), ExtResource("4_leaf_mid"), ExtResource("5_leaf_dark")])
+summer_material_variants = Array[Material]([ExtResource("3_leaf_light"), ExtResource("4_leaf_mid"), ExtResource("5_leaf_dark")])
+fall_material_variants = Array[Material]([ExtResource("9_leaf_autumn_light"), ExtResource("10_leaf_autumn"), ExtResource("11_leaf_autumn_mid"), ExtResource("12_leaf_autumn_dark")])
 secondary_variant_material_slot_names = PackedStringArray("wood", "wood_light", "wood_mid")
 secondary_material_variants = Array[Material]([ExtResource("6_wood_light"), ExtResource("7_wood_mid"), ExtResource("8_wood_dark")])
 collision_radius = 0.55
--- a/world/generation/props/definitions/prop_tree_3.tres
+++ b/world/generation/props/definitions/prop_tree_3.tres
@ -1,4 +1,4 @@
-[gd_resource type="Resource" script_class="TerrainPropDefinition" load_steps=9 format=3]
+[gd_resource type="Resource" script_class="TerrainPropDefinition" load_steps=13 format=3]

 [ext_resource type="Script" path="res://world/generation/terrain_prop_definition.gd" id="1_definition"]
 [ext_resource type="PackedScene" path="res://world/generation/props/assets/prop_tree_3.glb" id="2_scene"]
@ -8,6 +8,10 @@
 [ext_resource type="Material" path="res://world/generation/props/materials/wood_light.tres" id="6_wood_light"]
 [ext_resource type="Material" path="res://world/generation/props/materials/wood_mid.tres" id="7_wood_mid"]
 [ext_resource type="Material" path="res://world/generation/props/materials/wood_dark.tres" id="8_wood_dark"]
+[ext_resource type="Material" path="res://world/generation/props/materials/leaf_autumn_light.tres" id="9_leaf_autumn_light"]
+[ext_resource type="Material" path="res://world/generation/props/materials/leaf_autumn.tres" id="10_leaf_autumn"]
+[ext_resource type="Material" path="res://world/generation/props/materials/leaf_autumn_mid.tres" id="11_leaf_autumn_mid"]
+[ext_resource type="Material" path="res://world/generation/props/materials/leaf_autumn_dark.tres" id="12_leaf_autumn_dark"]

 [resource]
 script = ExtResource("1_definition")
@ -21,8 +25,10 @@ minimum_spawn_chunk_distance = 2
 clearance_radius = 1.8
 minimum_visual_scale = 0.7
 maximum_visual_scale = 1.2
-variant_material_slot_names = PackedStringArray("leaf_light", "leaf", "leaf_dark")
+variant_material_slot_names = PackedStringArray("leaf")
 material_variants = Array[Material]([ExtResource("3_leaf_light"), ExtResource("4_leaf_mid"), ExtResource("5_leaf_dark")])
+summer_material_variants = Array[Material]([ExtResource("3_leaf_light"), ExtResource("4_leaf_mid"), ExtResource("5_leaf_dark")])
+fall_material_variants = Array[Material]([ExtResource("9_leaf_autumn_light"), ExtResource("10_leaf_autumn"), ExtResource("11_leaf_autumn_mid"), ExtResource("12_leaf_autumn_dark")])
 secondary_variant_material_slot_names = PackedStringArray("wood", "wood_light", "wood_mid")
 secondary_material_variants = Array[Material]([ExtResource("6_wood_light"), ExtResource("7_wood_mid"), ExtResource("8_wood_dark")])
 collision_radius = 0.55
--- a/world/generation/props/definitions/prop_tree_large.tres
+++ b/world/generation/props/definitions/prop_tree_large.tres
@ -1,4 +1,4 @@
-[gd_resource type="Resource" script_class="TerrainPropDefinition" load_steps=9 format=3]
+[gd_resource type="Resource" script_class="TerrainPropDefinition" load_steps=13 format=3]

 [ext_resource type="Script" path="res://world/generation/terrain_prop_definition.gd" id="1_definition"]
 [ext_resource type="PackedScene" path="res://world/generation/props/assets/prop_tree_large.glb" id="2_scene"]
@ -8,6 +8,10 @@
 [ext_resource type="Material" path="res://world/generation/props/materials/wood_light.tres" id="6_wood_light"]
 [ext_resource type="Material" path="res://world/generation/props/materials/wood_mid.tres" id="7_wood_mid"]
 [ext_resource type="Material" path="res://world/generation/props/materials/wood_dark.tres" id="8_wood_dark"]
+[ext_resource type="Material" path="res://world/generation/props/materials/leaf_autumn_light.tres" id="9_leaf_autumn_light"]
+[ext_resource type="Material" path="res://world/generation/props/materials/leaf_autumn.tres" id="10_leaf_autumn"]
+[ext_resource type="Material" path="res://world/generation/props/materials/leaf_autumn_mid.tres" id="11_leaf_autumn_mid"]
+[ext_resource type="Material" path="res://world/generation/props/materials/leaf_autumn_dark.tres" id="12_leaf_autumn_dark"]

 [resource]
 script = ExtResource("1_definition")
@ -21,8 +25,10 @@ minimum_spawn_chunk_distance = 2
 clearance_radius = 2.5
 minimum_visual_scale = 0.75
 maximum_visual_scale = 1.2
-variant_material_slot_names = PackedStringArray("leaf_light", "leaf", "leaf_dark")
+variant_material_slot_names = PackedStringArray("leaf")
 material_variants = Array[Material]([ExtResource("3_leaf_light"), ExtResource("4_leaf_mid"), ExtResource("5_leaf_dark")])
+summer_material_variants = Array[Material]([ExtResource("3_leaf_light"), ExtResource("4_leaf_mid"), ExtResource("5_leaf_dark")])
+fall_material_variants = Array[Material]([ExtResource("9_leaf_autumn_light"), ExtResource("10_leaf_autumn"), ExtResource("11_leaf_autumn_mid"), ExtResource("12_leaf_autumn_dark")])
 secondary_variant_material_slot_names = PackedStringArray("wood", "wood_light", "wood_mid")
 secondary_material_variants = Array[Material]([ExtResource("6_wood_light"), ExtResource("7_wood_mid"), ExtResource("8_wood_dark")])
 collision_radius = 1.05
--- a/world/generation/props/materials/leaf_autumn.tres
+++ b/world/generation/props/materials/leaf_autumn.tres
@ -0,0 +1,9 @@
+[gd_resource type="StandardMaterial3D" format=3]
+
+[resource]
+resource_name = "leaf_autumn"
+albedo_color = Color(0.6186816, 0.4523746, 0, 1)
+metallic = 0.0
+roughness = 1.0
+shading_mode = 1
+texture_filter = 0
--- a/world/generation/props/materials/leaf_autumn_dark.tres
+++ b/world/generation/props/materials/leaf_autumn_dark.tres
@ -0,0 +1,9 @@
+[gd_resource type="StandardMaterial3D" format=3]
+
+[resource]
+resource_name = "leaf_autumn_dark"
+albedo_color = Color(0.3853541, 0.00134692, 0, 1)
+metallic = 0.0
+roughness = 1.0
+shading_mode = 1
+texture_filter = 0
--- a/world/generation/props/materials/leaf_autumn_light.tres
+++ b/world/generation/props/materials/leaf_autumn_light.tres
@ -0,0 +1,9 @@
+[gd_resource type="StandardMaterial3D" format=3]
+
+[resource]
+resource_name = "leaf_autumn_light"
+albedo_color = Color(0.8222013, 0.794216, 0, 1)
+metallic = 0.0
+roughness = 1.0
+shading_mode = 1
+texture_filter = 0
--- a/world/generation/props/materials/leaf_autumn_mid.tres
+++ b/world/generation/props/materials/leaf_autumn_mid.tres
@ -0,0 +1,9 @@
+[gd_resource type="StandardMaterial3D" format=3]
+
+[resource]
+resource_name = "leaf_autumn_mid"
+albedo_color = Color(0.6841143, 0.3515543, 0, 1)
+metallic = 0.0
+roughness = 1.0
+shading_mode = 1
+texture_filter = 0
--- a/world/generation/props/materials/leaf_dark.tres
+++ b/world/generation/props/materials/leaf_dark.tres
@ -2,7 +2,7 @@

 [resource]
 resource_name = "leaf_variant_dark"
-albedo_color = Color(0.1712, 0.252, 0, 1)
+albedo_color = Color(0.1712407, 0.2520192, 0, 1)
 metallic = 0.0
 roughness = 1.0
 shading_mode = 1
--- a/world/generation/props/materials/leaf_light.tres
+++ b/world/generation/props/materials/leaf_light.tres
@ -2,7 +2,7 @@

 [resource]
 resource_name = "leaf_variant_light"
-albedo_color = Color(0.3388, 0.7187, 0, 1)
+albedo_color = Color(0.3387566, 0.7186728, 0, 1)
 metallic = 0.0
 roughness = 1.0
 shading_mode = 1
--- a/world/generation/props/materials/leaf_mid.tres
+++ b/world/generation/props/materials/leaf_mid.tres
@ -2,7 +2,7 @@

 [resource]
 resource_name = "leaf_variant_mid"
-albedo_color = Color(0.3147, 0.4631, 0, 1)
+albedo_color = Color(0.3146831, 0.4631305, 0, 1)
 metallic = 0.0
 roughness = 1.0
 shading_mode = 1
--- a/world/generation/props/materials/palm_autumn.tres
+++ b/world/generation/props/materials/palm_autumn.tres
@ -0,0 +1,9 @@
+[gd_resource type="StandardMaterial3D" format=3]
+
+[resource]
+resource_name = "palm_autumn"
+albedo_color = Color(0.2951757, 0.3575695, 0.162893, 1)
+metallic = 0.0
+roughness = 1.0
+shading_mode = 1
+texture_filter = 0
--- a/world/generation/props/materials/palm_summer.tres
+++ b/world/generation/props/materials/palm_summer.tres
@ -0,0 +1,9 @@
+[gd_resource type="StandardMaterial3D" format=3]
+
+[resource]
+resource_name = "palm_summer"
+albedo_color = Color(0.3146831, 0.4631305, 0, 1)
+metallic = 0.0
+roughness = 1.0
+shading_mode = 1
+texture_filter = 0
--- a/world/generation/props/materials/pine_autumn.tres
+++ b/world/generation/props/materials/pine_autumn.tres
@ -0,0 +1,9 @@
+[gd_resource type="StandardMaterial3D" format=3]
+
+[resource]
+resource_name = "pine_autumn"
+albedo_color = Color(0.02388079, 0.1285609, 0, 1)
+metallic = 0.0
+roughness = 1.0
+shading_mode = 1
+texture_filter = 0
--- a/world/generation/props/materials/pine_summer.tres
+++ b/world/generation/props/materials/pine_summer.tres
@ -0,0 +1,9 @@
+[gd_resource type="StandardMaterial3D" format=3]
+
+[resource]
+resource_name = "pine_summer"
+albedo_color = Color(0.02171588, 0.2242201, 0.1360403, 1)
+metallic = 0.0
+roughness = 1.0
+shading_mode = 1
+texture_filter = 0
--- a/world/generation/terrain_prop_catalog.gd
+++ b/world/generation/terrain_prop_catalog.gd
@ -113,20 +113,40 @@ func validation_errors() -> PackedStringArray:
 				"%s has an invalid loose-cluster radius."
 				% definition.stable_id
 			)
+		var primary_material_palettes: Array[Array] = [
+			definition.material_variants,
+			definition.spring_material_variants,
+			definition.summer_material_variants,
+			definition.fall_material_variants,
+			definition.winter_material_variants,
+		]
+		var has_primary_material_variants := false
+		for palette: Array in primary_material_palettes:
+			has_primary_material_variants = (
+				has_primary_material_variants or not palette.is_empty()
+			)
+			for material: Material in palette:
+				if material == null:
+					errors.append(
+						"%s contains an empty primary material variant."
+						% definition.stable_id
+					)
+				elif not material is StandardMaterial3D:
+					errors.append(
+						(
+							"%s primary material variants must use "
+							+ "StandardMaterial3D so foliage wind is retained."
+						)
+						% definition.stable_id
+					)
 		if (
-			not definition.material_variants.is_empty()
+			has_primary_material_variants
 			and definition.variant_material_slot_names.is_empty()
 		):
 			errors.append(
-				"%s has material variants but no target material slots."
+				"%s has primary material variants but no target material slots."
 				% definition.stable_id
 			)
-		for material: Material in definition.material_variants:
-			if material == null:
-				errors.append(
-					"%s contains an empty material variant."
-					% definition.stable_id
-				)
 		if (
 			not definition.secondary_material_variants.is_empty()
 			and definition.secondary_variant_material_slot_names.is_empty()
--- a/world/generation/terrain_prop_definition.gd
+++ b/world/generation/terrain_prop_definition.gd
@ -1,6 +1,8 @@
 class_name TerrainPropDefinition
 extends Resource

+const CalendarSeasonType = preload("res://world/calendar_season.gd")
+
@export var stable_id: StringName
@export var label := ""
@export var packed_scene: PackedScene
@ -33,7 +35,15 @@ extends Resource
 ## A single material is chosen per prop and applied only to matching imported
 ## material slots. This keeps trunks untouched while varying foliage.
@export var variant_material_slot_names := PackedStringArray()
+## Legacy/default palette. It remains the final fallback for definitions that
+## have not been migrated to explicit seasonal palettes.
@export var material_variants: Array[Material] = []
+@export_group("Seasonal Primary Materials")
+@export var spring_material_variants: Array[Material] = []
+@export var summer_material_variants: Array[Material] = []
+@export var fall_material_variants: Array[Material] = []
+@export var winter_material_variants: Array[Material] = []
+@export_group("")
 ## An independent second material channel, used when both foliage and wood
 ## should vary without coupling their color choices.
@export var secondary_variant_material_slot_names := PackedStringArray()
@ -71,6 +81,28 @@ func supports_chunk_tags(chunk_tags: PackedStringArray) -> bool:
 	return true


+func primary_material_variants_for_season(
+	season: int,
+) -> Array[Material]:
+	var requested: Array[Material] = []
+	match season:
+		CalendarSeasonType.Season.SPRING:
+			requested = spring_material_variants
+		CalendarSeasonType.Season.SUMMER:
+			requested = summer_material_variants
+		CalendarSeasonType.Season.FALL:
+			requested = fall_material_variants
+		CalendarSeasonType.Season.WINTER:
+			requested = winter_material_variants
+	if not requested.is_empty():
+		return requested
+	# Spring and winter intentionally retain summer foliage until their authored
+	# palettes arrive. Unknown dates use the same stable visual fallback.
+	if not summer_material_variants.is_empty():
+		return summer_material_variants
+	return material_variants
+
+
 func has_collision() -> bool:
 	return has_cylinder_collision() or has_box_collision()

--- a/world/regions/world_region.gd
+++ b/world/regions/world_region.gd
@ -42,6 +42,10 @@ func set_water_motion_strength_multiplier(_multiplier: float) -> void:
 	pass


+func set_calendar_season(_season: int) -> void:
+	pass
+
+
 func get_playable_half_extents() -> Vector2:
 	return Vector2(50.0, 50.0)

--- a/world/test_world.gd
+++ b/world/test_world.gd
@ -14,6 +14,7 @@ const RVUpgradeInteractionType = preload(
 	"res://world/rv_upgrade_interaction.gd"
 )
 const WorldLayoutType = preload("res://world/world_layout.gd")
+const CalendarSeasonType = preload("res://world/calendar_season.gd")
 const GENERATED_REGION_SCENE: PackedScene = preload(
 	"res://world/generation/generated_world_region.tscn"
 )
@ -38,6 +39,7 @@ var _world_seed: int = PlayerSaveManager.DEFAULT_WORLD_SEED
 var _light_performance_profile: bool = false
 var _foliage_wind_strength_multiplier: float = 1.0
 var _water_motion_strength_multiplier: float = 1.0
+var _calendar_season: int = CalendarSeasonType.UNKNOWN
 var _dedicated_simulation: bool = false
 var _local_home_interior_presentation_active: bool = false

@ -118,6 +120,16 @@ func set_water_motion_strength_multiplier(multiplier: float) -> void:
 		)


+func set_calendar_season(season: int) -> void:
+	_calendar_season = (
+		season
+		if season >= 0 and season < CalendarSeasonType.Season.size()
+		else CalendarSeasonType.UNKNOWN
+	)
+	if _active_region != null:
+		_active_region.set_calendar_season(_calendar_season)
+
+
 func set_local_home_interior_presentation_active(enabled: bool) -> void:
 	_local_home_interior_presentation_active = enabled
 	if _active_region != null and not _dedicated_simulation:
@ -296,6 +308,7 @@ func get_gatherable_spawn_positions(
 func _ready() -> void:
 	if _active_region != null:
 		_world_layout = _active_region.region_id
+		_active_region.set_calendar_season(_calendar_season)
 	_configure_world_coverage()


@ -318,6 +331,7 @@ func _replace_active_region(layout: StringName, world_seed: int) -> bool:
 		return false
 	if layout == WorldLayoutType.GENERATED:
 		replacement.set("initial_seed", world_seed)
+	replacement.set_calendar_season(_calendar_season)
 	if _active_region != null:
 		_regions_root.remove_child(_active_region)
 		_active_region.free()