A 3D Starter First Person look & movement script for Godot

Player.gd

extends KinematicBody

export(NodePath) var cam_path
const MOVE_SPEED = 5.0 
const MOUSE_SENSITIVITY = 0.0010

var _camera:Camera
var _player_input:Vector3
var _velocity:Vector3

func _ready():
	_camera = get_node(cam_path)
	assert(_camera)
	Input.set_mouse_mode(Input.MOUSE_MODE_CAPTURED)

func _physics_process(delta:float):
	_move(delta)

func _unhandled_input(event):
	_player_input = Vector3(
		Input.get_axis("move_left","move_right"),
		0,
		Input.get_axis("move_forward","move_backward")
	).normalized()

	if event is InputEventMouseMotion:
		_head_look(-event.relative)

func get_move_direction() -> Vector3:
	return (_camera.global_transform.basis * _player_input).normalized()
	
func _move(delta:float) -> void:
	var dir = get_move_direction()
	var new_vel:Vector3 = dir * MOVE_SPEED 
	_velocity.y += -9.8 * delta
	new_vel.y = _velocity.y
	_velocity = new_vel
	_velocity = move_and_slide(_velocity,Vector3.UP)

func _head_look(motion:Vector2):
	_camera.rotation.x = clamp(_camera.rotation.x + motion.y * MOUSE_SENSITIVITY  , -PI / 2 , PI / 2)
	_camera.rotate_y(motion.x * MOUSE_SENSITIVITY)
	_camera.orthonormalize()