Update turret script to account for gravity when firing.

objects/buildings/turret.tscn

@@ -29,9 +29,11 @@ ammo_cap = 10
 fire_cooldown_time = 0.2
 reload_time = 1.0
 bullet_scene = ExtResource("3_kpsgq")
-fire_position = Vector3(0, 1, 0)
-shot_impulse = 100.0
-lead_shot_factor = 0.01
+fire_position = Vector3(0, 2.1, 0)
+shot_velocity = 20.0
+lead_shots = true
+compensate_for_gravity = true
+use_artillery_firing_solution = false
 
 [node name="MeshInstance3D" parent="." index="0"]
 material_override = SubResource("StandardMaterial3D_cgb0l")

objects/bullet.tscn

@@ -110,6 +110,7 @@ continuous_cd = true
 contact_monitor = true
 max_contacts_reported = 1
 script = ExtResource("1_rsjgb")
+damage_per_speed = 100.0
 min_damage = 1.0
 lifetime = 5.0
 

scripts/buildings/turret.gd

@@ -1,12 +1,20 @@
 extends Building
+class_name Turret
 
-@export var ammo_cap: int = 10
-@export var fire_cooldown_time: float = 0.2
-@export var reload_time: float = 1.0
-@export var bullet_scene: PackedScene = preload("res://objects/bullet.tscn")
-@export var fire_position: Vector3 = Vector3(0,1,0)
-@export var shot_impulse: float = 100
-@export var lead_shot_factor: float = 0.01
+@export_group("Ammunition")
+@export var ammo_cap: int = 10 ## The number of shots per "magazine", i.e. reload.
+@export var fire_cooldown_time: float = 0.2 ## The time between shots, in seconds.
+@export var reload_time: float = 1.0 ## The time taken to reload, in seconds.
+
+@export_group("Bullet Spawning")
+@export var bullet_scene: PackedScene = preload("res://objects/bullet.tscn") ## The entity to spawn as a bullet.
+@export var fire_position: Vector3 = Vector3(0,1,0) ## The local position to fire from.
+
+@export_group("Ballistics")
+@export var shot_velocity: float = 100 ## The velocity that bullets are fired at, in m/s.
+@export var lead_shots: bool = true ## Turn on to make the turret aim ahead of moving targets.
+@export var compensate_for_gravity: bool = true ## Turn on to make the turret aim above distant targets to arc it's shots.
+@export var use_artillery_firing_solution: bool = false ## If compensating for gravity, turn this on to make the turret aim high instead of low.
 
 enum LoadState {UNLOADED, RELOADING, LOADED}
 
@@ -23,7 +31,6 @@ func _process(delta: float) -> void:
 	super(delta)
 	if loaded == LoadState.UNLOADED:
 		if consumer.take_any_item_from_storage():
-			#Engine.time_scale = 1.0
 			loaded = LoadState.RELOADING
 	if loaded == LoadState.RELOADING:
 		reload_timer += delta
@@ -70,17 +77,55 @@ func fire_at_target() -> void:
 	#Engine.time_scale = 0.1
 	var bullet: RigidBody3D = bullet_scene.instantiate()
 	add_child(bullet)
-	bullet.global_position = to_global(fire_position)
+	var bullet_pos: Vector3 = to_global(fire_position)
+	bullet.global_position = bullet_pos
+	
+	var target_range: float = bullet_pos.distance_to(current_target.global_position)
+	var shot_time: float = (target_range / shot_velocity)
 	
 	var aim_target: Vector3 = current_target.global_position
-	var target_range: float = global_position.distance_to(current_target.global_position)
-	aim_target += current_target.linear_velocity * lead_shot_factor * target_range
-	DebugDraw3D.draw_sphere(aim_target, 0.25, Color.RED, 0.1)
+	if lead_shots:
+		aim_target += current_target.linear_velocity * shot_time
+		target_range = bullet_pos.distance_to(aim_target)
+	DebugDraw3D.draw_sphere(aim_target, 0.25, Color.RED, shot_time)
 	
-	bullet.look_at(aim_target)
-	bullet.apply_impulse((aim_target - bullet.global_position).normalized()*shot_impulse)
+	var fire_direction: Vector3
+	if compensate_for_gravity:
+		var elevation: float = find_fire_angle(target_range, aim_target.y - bullet_pos.y, use_artillery_firing_solution)
+		var azimuth: float = Vector3.FORWARD.signed_angle_to(aim_target-global_position, Vector3.UP)
+		print("Shot params: θ=%d φ=%d" % [rad_to_deg(elevation), rad_to_deg(azimuth)])
+		if elevation < -PI or elevation > PI:
+			print("wtf?? θ=%d" % rad_to_deg(elevation))
+			return
+		fire_direction = Vector3.FORWARD
+		fire_direction = fire_direction.rotated(Vector3(1,0,0), elevation)
+		fire_direction = fire_direction.rotated(Vector3(0,1,0), azimuth)
+	else:
+		fire_direction = (aim_target - bullet_pos).normalized()
+		
+	DebugDraw3D.draw_arrow_ray(bullet_pos, fire_direction, target_range, Color.RED, 0.5, true, shot_time)
+	
+	bullet.look_at(bullet_pos+fire_direction)
+	bullet.linear_velocity = (-bullet.global_basis.z) * shot_velocity
+	#bullet.apply_impulse((aim_target - bullet.global_position).normalized()*shot_impulse)
 	bullet.angular_velocity = (bullet.global_basis * Vector3(0,0,-10))
 	current_target = null
 	ammo -= 1
 	if ammo <= 0:
+		Engine.time_scale = 1.0
 		loaded = LoadState.UNLOADED
+		
+func find_fire_angle(distance: float, height: float, high_solution: bool = true) -> float:
+	# theta = arctan( ( (v^2) ± sqrt( v^4 - g*( g*x^2 + 2*y*v^2 ) ) ) / g*x )
+	const g: float = 9.8
+	var gx2: float = g * pow(distance, 2)
+	var twoyv2: float = 2 * height * pow(shot_velocity,2)
+	var v2: float = pow(shot_velocity, 2)
+	var v4: float = pow(shot_velocity, 4)
+	
+	var arc_x: float = g * distance
+	var arc_y_offs: float = sqrt(v4 - g * (gx2 + twoyv2))
+	var arc_y: float = v2 + arc_y_offs * (1 if high_solution else -1)
+	
+	var theta: float = atan2(arc_y, arc_x)
+	return clamp(theta, -PI/2, PI/2)