Godot Fly camera utility - Single file

FlyCam.gd

extends Camera3D
class_name FlyCamera
## Simple Fly Camera for Godot Engine 3.x / 4.x.
## This Fly camera can be moved using the mouse and keyboard "WASD".
## You can toggle this camera activation by pressing the TAB key.
## The idea is to put this camera as autoload.
## It's possible to customize it by changing: The mouse `sensibility` and camera `speed`.
## 
## If you want to contribute, please leave a comment, I'll update the code.
## 
## License: MIT. 
## 
## ~~~~~~~~~~~~~~~~
## Make this discoverable by people:
## How to create a fly camera in Godot?
## Godot fly camera.
## Fly camera tutorial.
## Fly camera utility.
## ~~~~~~~~~~~~~~~~
## 

# ------------------------------------------------------------------------ Const
const speed = 0.1
const sensitivity = 0.001


# ----------------------------------------------------------------------- Global
var active := false
var motion: Vector3
var view_motion: Vector2
var gimbal_base: Transform
var gimbal_pitch: Transform
var gimbal_yaw: Transform


# ----------------------------------------------------------------------- Public
func is_active() -> bool:
	""" Return true when the fly camera is active. You can toggle the fly
	camera using the TAB keyboard. """
	return active


# ----------------------------------------------------------------- Notification
func _ready():
	gimbal_base.origin = global_transform.origin
	# Unparent
	set_as_top_level(true)
	update_activation()


func _input(event):
	if event is InputEventMouseMotion:
		view_motion += event.relative
		get_viewport().set_input_as_handled()

	elif event is InputEventKey:
		if event.keycode == KEY_TAB:
			if event.pressed:
				# Each click toggle.
				active = active == false
				update_activation()
				return

		if active == false:
			return

		var value: float = 0
		if event.pressed:
			value = 1

		Input.set_mouse_mode(Input.MOUSE_MODE_CAPTURED)
		if event.keycode == KEY_W:
			motion.z = value * -1.0
		elif event.keycode == KEY_S:
			motion.z = value
		elif event.keycode == KEY_A:
			motion.x = value * -1.0
		elif event.keycode == KEY_D:
			motion.x = value
		else:
			Input.set_mouse_mode(Input.MOUSE_MODE_VISIBLE)

		get_viewport().set_input_as_handled()


func _process(delta):
	gimbal_base *= Transform(Basis(), global_transform.basis * (motion * speed))

	gimbal_yaw = gimbal_yaw.rotated(Vector3(0,1,0), view_motion.x * sensitivity * -1.0)
	gimbal_pitch = gimbal_pitch.rotated(Vector3(1,0,0), view_motion.y * sensitivity * -1.0)
	view_motion = Vector2()

	global_transform = gimbal_base * (gimbal_yaw * gimbal_pitch)


# ---------------------------------------------------------------------- Private
func update_activation():
	set_process(active)
	current = active
	if active == false:
		Input.set_mouse_mode(Input.MOUSE_MODE_VISIBLE)