Here is a 2D analog for what you're trying to accomplish:
onready var nav = $Navigation2D
var destination = null
var navigation_path = []
func _physics_process(delta: float) -> void:
if destination:
move_towards_position(destination, delta)
# if we're close enough, call it good
if self.position.distance_squared_to(destination) < 5:
self.position = destination
destination = null
elif not navigation_path.empty():
destination = navigation_path.pop_front()
func _input(event: InputEvent) -> void:
var start_position = self.position
var end_position = get_end_position(event)
var path = Array(nav.get_simple_path(start_position, end_position))
if path.empty():
return
else:
var always_starting_position = path.pop_front()
navigation_path = path
Obviously, you'll need to implement move_towards_position() and get_end_position(). Something to keep in mind: get_simple_path() wants and returns points in local coordinate space, if i recall correctly, moving in 3D generally wants points in global space.