feat: finishes lightning scene, adds more exposed options

Lightning effects are visually polished and many options are exposed as export variables (color and albedo gradient, distance, spawn-interval).

Lightnings are now more "grouped" and arent just randomly spawned around the player; can be adjusted via rotation degrees

Refs: #312

World/Environment/Lightning.gd

@@ -1,43 +1,68 @@
 extends Node3D
 
-
+func set_enabled(val):
+	if has_node("Timer"):
+		if enabled:
+			get_node("Timer").start()
+		else:
+			get_node("Timer").stop()
 @export var enabled := false : 
-	set(is_enabled):
-		enabled = is_enabled
-		if has_node("Timer"):
-			if enabled:
-				get_node("Timer").start()
-			else:
-				get_node("Timer").stop()
-@export var time_interval_from := 0.1
-@export var time_interval_to := 10
-
+	set(val): 
+		enabled = val 
+		set_enabled(val)
+
+# Randomly choose a number (in seconds) in the interval for 
+# spawning a new lightning 
+@export var spawn_interval_from := 0.5
+@export var spawn_interval_to := 10.0
+
+# Distance between center and lightning
+@export var min_distance := 500
+@export var max_distance := 2000
+
+# Gradient when the lightning is on/off (i.e. flickering)
+@export var gradient_on: Gradient
+@export var gradient_off: Gradient
+
+func set_color(val):
+	if has_node("MeshInstance3d/LightNing"):
+		get_node("MeshInstance3d/LightNing").light_color = color
+	if has_node("MeshInstance3d"):
+		get_node("MeshInstance3d").material_override.emission = color
+@export var color: Color : 
+	set(val): 
+		color = val
+		set_color(val)
+
+# 0 => north, 90 => east, 180 => south, 270 => west 
+@export var rot_degrees := 0.0 : 
+	set(deg): rot_degrees = deg
 
 @onready var light = $MeshInstance3d/LightNing
-@onready var lightning_mesh = $MeshInstance3d
 @onready var line: Line2D = $MeshInstance3d/SubViewport/Line2d
-@onready var timer = $Timer
 
 var center_node: Node3D 
 
 
 func _ready():
-	timer.timeout.connect(_on_timer_timeout)
-	if enabled: timer.start()
+	$Timer.timeout.connect(_on_timer_timeout)
+	set_enabled(enabled)
+	set_color(color)
 
 
 func _create_lightning_branch(num_segments: int):
 	line.clear_points()
-	line.add_point(Vector2(50, 0))
-	$MeshInstance3d/SubViewport/Sprite2D.position = Vector2(50, 6)
+	line.add_point(Vector2(0, 0))
 	for i in range(num_segments):
 		var point_before = line.points[i]
-		line.add_point(Vector2(_sample_gaussian(0.5) + point_before.x * randf(), _sample_gaussian(0.8) + point_before.y))
-#	$MeshInstance3d/SubViewport/Sprite2D2.position = line.get_point_position(num_segments)
+		line.add_point(Vector2(
+			_sample_gaussian(1.5) + point_before.x * randf(), 
+			_sample_gaussian(0.8) + point_before.y))
 
 
-# Approximate via  central limit theorem (Irwin-Hall)
+# Approximate a number via central limit theorem (Irwin Hall)
 func _sample_gaussian(stdev_multiplier: float):
+	# aprox gauss will be approximately 6
 	var approx_gauss = 12
 	for i in range(12):
 		approx_gauss -= randf() 
@@ -46,34 +71,45 @@ func _sample_gaussian(stdev_multiplier: float):
 
 
 func _animate_():
+	# Rotate the light accordingly
 	self.light.look_at(center_node.position)
 
 	var tween_lighting = create_tween()
 	var tween_light = create_tween()
 
-	for i in range(randf_range(3, 6)):
-		var time_light_on = randf_range(.05, .1)
-		var time_light_off = randf_range(.05, .1)
+	# Simulate "flickering" of lightning
+	for i in range(randf_range(2, 5)):
+		var time_light_on = randf_range(.05, .2)
+		var time_light_off = randf_range(.15, .15)
 
-		var energy_light_on = randf_range(.4, 1.)
-		var energy_light_off = randf_range(.0, .5)
+		var dist_to_center = $MeshInstance3d.position.distance_to(center_node.position)
+		var distance_multiplier = remap(dist_to_center, min_distance, max_distance, 1.5, 0.5)
+		var energy_light_on = randf_range(1., 5.)
 
-		tween_lighting.tween_property(self.line, "default_color:a", energy_light_off, time_light_off)
-		tween_lighting.tween_property(self.line, "default_color:a", energy_light_on, time_light_on)
+		tween_lighting.tween_property(line, "gradient", gradient_off, time_light_off)
+		tween_lighting.tween_property(line, "gradient", gradient_on, time_light_on)
 
-		tween_light.tween_property(self.light, "light_energy", energy_light_off, time_light_off)
-		tween_light.tween_property(self.light, "light_energy", energy_light_on, time_light_on)
+		tween_light.tween_property(
+			light, "light_energy", 0.3 * distance_multiplier, time_light_off)
+		tween_light.tween_property(
+			light, "light_energy", energy_light_on * distance_multiplier, time_light_on)
 
-	tween_light.tween_property(self.light, "light_energy", 0.0, 5.1)
-	tween_lighting.tween_property(self.line, "default_color:a", 0.0, 5.1)
+	# Reset to invisible
+	tween_light.tween_property(light, "light_energy", 0.0, 0.2)
+	tween_lighting.tween_property(line, "gradient", gradient_off, 0.2)
 
 
 func fire():
-	_create_lightning_branch(30)
-	$MeshInstance3d.position = center_node.position + Vector3(randi_range(-3000, 3000), 0, randi_range(-3000, 3000))
+	_create_lightning_branch(randi_range(10, 50))
+	var rand_angle = randf_range(rot_degrees - 10, rot_degrees + 10)
+	$MeshInstance3d.position = center_node.position + Vector3(
+		0, 0, randi_range(-min_distance, -max_distance))
+	$MeshInstance3d.position = center_node.position + \
+		($MeshInstance3d.position - center_node.position).rotated(Vector3.UP, deg_to_rad(rand_angle))
 	_animate_()
 
 
+# Repeating call of this function on timer timeout
 func _on_timer_timeout():
 	fire()
-	timer.wait_time = randf_range(time_interval_from, time_interval_to)
+	$Timer.wait_time = randf_range(spawn_interval_from, spawn_interval_to)

World/Environment/Lightning.gdshader

@@ -0,0 +1,5 @@
+shader_type canvas_item;
+
+void fragment() {
+	// Place fragment code here.
+}

World/Environment/Lightning.tscn

@@ -1,34 +1,45 @@
-[gd_scene load_steps=6 format=3 uid="uid://cib4g5bstb1xa"]
+[gd_scene load_steps=7 format=3 uid="uid://cib4g5bstb1xa"]
 
 [ext_resource type="Script" path="res://World/Environment/Lightning.gd" id="1_2eur0"]
-[ext_resource type="Texture2D" uid="uid://b4u8j5mea7xd4" path="res://Resources/Textures/RainSplash.png" id="2_xe28t"]
+
+[sub_resource type="Gradient" id="Gradient_gnng6"]
+offsets = PackedFloat32Array(0, 0.431373, 1)
+colors = PackedColorArray(0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 0)
+
+[sub_resource type="Gradient" id="Gradient_kbe6e"]
+offsets = PackedFloat32Array(1)
+colors = PackedColorArray(1, 1, 1, 0)
 
 [sub_resource type="ViewportTexture" id="ViewportTexture_schoq"]
 viewport_path = NodePath("MeshInstance3d/SubViewport")
 
 [sub_resource type="StandardMaterial3D" id="StandardMaterial3D_dju3a"]
 resource_local_to_scene = true
 transparency = 1
+cull_mode = 2
 albedo_texture = SubResource("ViewportTexture_schoq")
 emission_enabled = true
 emission = Color(0.462745, 0.537255, 1, 1)
 emission_energy_multiplier = 10.0
 billboard_mode = 2
 
 [sub_resource type="PlaneMesh" id="PlaneMesh_h6sm4"]
-size = Vector2(150, 750)
+size = Vector2(500, 500)
 orientation = 2
 
 [node name="Lightning" type="Node3D"]
 script = ExtResource("1_2eur0")
 enabled = true
-time_interval_to = 1
+spawn_interval_to = 3.0
+gradient_on = SubResource("Gradient_gnng6")
+gradient_off = SubResource("Gradient_kbe6e")
+color = Color(0.788235, 0.776471, 1, 1)
+rot_degrees = 180.0
 
 [node name="Timer" type="Timer" parent="."]
 autostart = true
 
 [node name="MeshInstance3d" type="MeshInstance3D" parent="."]
-transform = Transform3D(-4.37114e-08, 0, -1, 0, 1, 0, 1, 0, -4.37114e-08, -443.156, -88.0528, -0.99136)
 material_override = SubResource("StandardMaterial3D_dju3a")
 mesh = SubResource("PlaneMesh_h6sm4")
 
@@ -38,22 +49,20 @@ transparent_bg = true
 handle_input_locally = false
 msaa_2d = 3
 use_taa = true
-size = Vector2i(100, 500)
+size = Vector2i(500, 500)
 render_target_update_mode = 4
 
-[node name="Sprite2D" type="Sprite2D" parent="MeshInstance3d/SubViewport"]
-scale = Vector2(0.05, 0.05)
-texture = ExtResource("2_xe28t")
-
 [node name="Line2d" type="Line2D" parent="MeshInstance3d/SubViewport"]
 width = 2.0
 default_color = Color(0.501961, 0.541176, 1, 1)
+gradient = SubResource("Gradient_gnng6")
 
 [node name="LightNing" type="DirectionalLight3D" parent="MeshInstance3d"]
-transform = Transform3D(-0.605916, -0.326285, 0.725538, 0, 0.912019, 0.410148, -0.795529, 0.248515, -0.552607, 0, -0.018, 0)
+transform = Transform3D(1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 500, 0)
 rotation_edit_mode = 2
+layers = 7
 light_color = Color(0.72549, 0.839216, 0.945098, 1)
 light_energy = 0.0
-light_indirect_energy = 5.0
-light_volumetric_fog_energy = 5.0
+light_indirect_energy = 0.1
+light_volumetric_fog_energy = 0.5
 shadow_enabled = true

World/Environment/WorldEnvironment.gd

@@ -79,3 +79,7 @@ func _set_light_energy(new_energy):
 
 func set_lightning_enabled(enabled: bool):
 	$Lightning.enabled = enabled
+
+
+func set_lightning_rotation(rotation_deg: float):
+	$Lightning.rot_degrees = rotation_deg

World/Environment/WorldEnvironment.tscn

@@ -76,4 +76,3 @@ mesh = SubResource("SphereMesh_v0nf7")
 [node name="Rain" parent="." instance=ExtResource("6_wusnq")]
 
 [node name="Lightning" parent="." instance=ExtResource("7_canqr")]
-enabled = true

World/WeatherManager.gd

@@ -10,6 +10,7 @@ signal rain_density_changed(new_rain_density)
 signal rain_drop_size_changed(new_rain_density)
 signal rain_enabled_changed(enabled)
 signal lightning_enabled_changed(enabled)
+signal lightning_rotation_changed(rotation_degrees)
 
 # 0..100 = "clear visibility".."strong haziness"
 var visibility = 0 :
@@ -69,4 +70,10 @@ var lightning_enabled := false :
 		return lightning_enabled
 	set(enabled):
 		lightning_enabled = enabled
+		lightning_enabled_changed.emit(lightning_enabled)
 
+
+var lightning_rotation := 0 :
+	set(val):
+		lightning_rotation = val
+		lightning_rotation_changed.emit(lightning_rotation)

World/World.gd

@@ -25,6 +25,7 @@ func _ready():
 	$WeatherManager.rain_density_changed.connect($WorldEnvironment.apply_rain_density)
 	$WeatherManager.rain_drop_size_changed.connect($WorldEnvironment.apply_rain_drop_size)
 	$WeatherManager.lightning_enabled_changed.connect($WorldEnvironment.set_lightning_enabled)
+	$WeatherManager.lightning_rotation_changed.connect($WorldEnvironment.set_lightning_rotation)
 
 	$PositionManager.new_center_node.connect(func(center_node: Node3D): 
 		_add_remote_transform(center_node, $WorldEnvironment/Rain, "RainRemoteTransformer"))