added damping force

car.gd

@@ -6,3 +6,7 @@ extends RigidBody3D
 func _physics_process(_delta: float) -> void:
 	for wheel: Wheel in wheels:
 		wheel.apply_forces(self)
+
+##Point argument is in local space
+func get_velocity_at_point(point: Vector3) -> Vector3:
+	return linear_velocity + angular_velocity.cross(point - center_of_mass)

wheel.gd

@@ -4,6 +4,7 @@ extends RayCast3D
 @export var wheel_radius: float = 0.316
 @export var suspension_rest_length: float = 0.1
 @export var suspension_stiffness: float = 250_000
+@export var suspension_damping: float = 2000
 
 func _ready() -> void:
 	target_position *= suspension_rest_length + wheel_radius
@@ -11,10 +12,10 @@ func _ready() -> void:
 func apply_forces(car: Car) -> void:
 	force_raycast_update()
 	
-	var force: Vector3 = get_suspension_force()
+	var force: Vector3 = get_suspension_force(car)
 	car.apply_force(force, car.to_local(get_collision_point()))
 
-func get_suspension_force() -> Vector3:
+func get_suspension_force(car: Car) -> Vector3:
 	var up: Vector3 = global_basis.y
 	if not is_colliding():
 		$"RX-Wheel".position = -up * suspension_rest_length
@@ -26,7 +27,13 @@ func get_suspension_force() -> Vector3:
 	var suspension_length: float = -up.dot(wheel_center)
 	var suspension_displacement: float = suspension_rest_length - suspension_length
 	#https://en.wikipedia.org/wiki/Hookes_law
-	var y_force_scalar: float = suspension_stiffness * suspension_displacement
+	var hookes_force_scalar: float = suspension_stiffness * suspension_displacement
+	
+	var wheel_velocity: Vector3 = car.get_velocity_at_point(car.to_local(to_global(wheel_center)))
+	var wheel_up_velocity: float = up.dot(wheel_velocity)
+	var damping_force_scalar: float = suspension_damping * wheel_up_velocity
+	
+	var y_force_scalar: float = hookes_force_scalar - damping_force_scalar
 	var force: Vector3 = Vector3.UP * y_force_scalar
 	
 	return force