add client prediction

project.godot

@@ -13,7 +13,7 @@ config_version=5
 config/name="Instructions Clear"
 run/main_scene="res://scenes/empty.tscn"
 config/features=PackedStringArray("4.3", "Mobile")
-run/max_fps=240
+run/max_fps=120
 boot_splash/show_image=false
 config/icon="res://icon.svg"
 run/size/borderless=false

scenes/house.tscn

@@ -143,14 +143,12 @@ mesh = SubResource("BoxMesh_lm401")
 
 [node name="FirstFloorLight" type="OmniLight3D" parent="Lights"]
 transform = Transform3D(1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 4, 0)
-light_energy = 6.0
 shadow_enabled = true
 omni_range = 40.0
 omni_attenuation = 1.5
 
 [node name="SecondFloorLight" type="OmniLight3D" parent="Lights"]
 transform = Transform3D(1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 9, 0)
-light_energy = 6.0
 shadow_enabled = true
 omni_range = 40.0
 omni_attenuation = 1.5

scenes/runner.tscn

@@ -116,3 +116,5 @@ script = ExtResource("7_jfat4")
 [node name="Walk" type="Node" parent="StateMachine"]
 unique_name_in_owner = true
 script = ExtResource("8_phh70")
+
+[connection signal="delta_synchronized" from="Sync" to="." method="_on_sync_delta_synchronized"]

scripts/runner.gd

@@ -19,10 +19,16 @@ extends CharacterBody3D
 @export var air_deceleration := 5.0
 @export var rotation_speed := 20.0
 
-@export_group("Client Tweening")
+@export_group("Client Smoothing")
 @export var client_smoothing := false
 @export var client_smoothing_speed := 10.0
 @export var client_smoothing_rotation_speed := 25.0
+@export var client_prediction := false
+@export var client_prediction_tolerance := 0.3
+
+@export_group("Server variables")
+@export var server_position := Vector3.ZERO
+@export var server_rotation := Vector3.ZERO
 
 @onready var _camera_pivot: Node3D = %CameraPivot
 @onready var _camera_platform: Node3D = %CameraPlatform
@@ -32,9 +38,8 @@ extends CharacterBody3D
 var camera_input_direction := Vector2.ZERO
 var last_direction := Vector3.FORWARD
 
-@export_group("Server variables")
+var predicted_position := Vector3.ZERO
-@export var server_position := Vector3.ZERO
+var predicted_rotation := Vector3.ZERO
-@export var server_rotation := Vector3.ZERO
 
 func _ready() -> void:
 	state_machine.set_subject(self)
@@ -80,6 +85,11 @@ func _physics_process(delta: float) -> void:
 		camera_input_direction = Vector2.ZERO
 
 	if not multiplayer.is_server():
+		if multiplayer.get_unique_id() == player_id and client_prediction:
+			predicted_position = position
+			predicted_rotation = skin.global_rotation
+
+		if multiplayer.get_unique_id() != player_id or not client_prediction:
 			if client_smoothing:
 				position = lerp(position, server_position, client_smoothing_speed * delta)
 				skin.global_rotation.y = lerp_angle(skin.global_rotation.y, server_rotation.y, client_smoothing_rotation_speed * delta)
@@ -90,4 +100,9 @@ func _physics_process(delta: float) -> void:
 	if multiplayer.is_server():
 		server_position = position
 		server_rotation = skin.global_rotation
-		#print("Velocity: %s" % velocity)
+		pass
+
+func _on_sync_delta_synchronized() -> void:
+	if client_prediction and server_position.distance_to(predicted_position) > client_prediction_tolerance:
+		print("%v VS %v" % [server_position, predicted_position])
+		position = server_position

scripts/states/fall.gd

@@ -1,7 +1,7 @@
 extends State
 
 func process_physics(delta: float) -> State:
-	if not multiplayer.is_server():
+	if not multiplayer.is_server() and (multiplayer.get_unique_id() != subject.player_id or not subject.client_prediction):
 		return
 
 	var target_velocity = Vector3(0, subject.velocity.y, 0)

scripts/states/idle.gd

@@ -1,7 +1,7 @@
 extends State
 
 func process_physics(delta: float) -> State:
-	if not multiplayer.is_server():
+	if not multiplayer.is_server() and (multiplayer.get_unique_id() != subject.player_id or not subject.client_prediction):
 		return
 
 	var target_velocity = Vector3(0, subject.velocity.y, 0)

scripts/states/run.gd

@@ -1,7 +1,7 @@
 extends State
 
 func process_physics(delta: float) -> State:
-	if not multiplayer.is_server():
+	if not multiplayer.is_server() and (multiplayer.get_unique_id() != subject.player_id or not subject.client_prediction):
 		return
 
 	var input_direction = %Input.direction

scripts/states/state_machine.gd

@@ -14,7 +14,7 @@ func _change_state(new_state: State) -> void:
 		current_state.exit()
 
 	current_state = new_state
-	print("Entering: %s" % current_state.name)
+	#print("Entering: %s" % current_state.name)
 	current_state.enter()
 
 func process_physics(delta: float) -> void:

scripts/states/walk.gd

@@ -1,7 +1,7 @@
 extends State
 
 func process_physics(delta: float) -> State:
-	if not multiplayer.is_server():
+	if not multiplayer.is_server() and (multiplayer.get_unique_id() != subject.player_id or not subject.client_prediction):
 		return
 
 	var input_direction = %Input.direction