Hi all.
I am having a hard time figuring out how to use the 2d navigation system in Godot RC 3.
From what I can understand, the NavigationAgent2D node needs a NavMesh to know where it can navigate.

Unfortunately I cannot create this node in the Godot RC 3 edition,. Is this an issue with the current pre-release or am I approaching this wrong?
When I try to use the NavgiationAgent2D node without anything else to set the target position as
navigation_agent2d.set_target_postion(myStaticBody2D.global_position)
It returns false when I check if the object is reachable
navigation_agent2d.is_target_reachable()

If i use the "direction_to" as seen below, it works fine
position.direction_to(myStaticBody2D.global_position')

I can't make my character move, too. nav_agent.get_next_path_position() return my character's position.

I also get false from print_debug(nav_agent.is_target_reachable()), is there any thing wrong?

What do you mean in

If i use the "direction_to" as seen below, it works fine
position.direction_to(myStaticBody2D.global_position')

Do you mean you manage a way to make nav agent move?

It is my scene and script, same as tutorial: https://docs.godotengine.org/en/latest/tutorials/navigation/navigation_using_navigationagents.html

extends CharacterBody2D

@export var tilemap : TileMap
@export var target : Node2D

@onready var nav_agent : NavigationAgent2D = $NavigationAgent2D

const SPEED = 300.0

func _ready():
	nav_agent.avoidance_enabled = true
	
	var desired_distance : float = floor(SPEED / 100)
	nav_agent.path_desired_distance = desired_distance
	nav_agent.target_desired_distance = desired_distance
	
	nav_agent.connect("velocity_computed", Callable(self, "_on_CharacterNavAgent_velocity_computed"))
	nav_agent.set_navigation_map(tilemap.get_navigation_map(0))
	nav_agent.set_target_position(target.position)
	nav_agent.get_next_path_position()
	
	print_debug(nav_agent.is_target_reachable())
	
func _physics_process(delta):
	if not nav_agent.is_navigation_finished():
		var cur_pos = global_position
		var tar_pos = nav_agent.get_next_path_position()
		var agent_velocity = cur_pos.direction_to(tar_pos).normalized() * SPEED
		nav_agent.set_velocity(agent_velocity)

func _on_CharacterNavAgent_velocity_computed(safe_velocity: Vector2) -> void:
	velocity = safe_velocity
	move_and_slide()

Godot Version: v4.0.rc4.official [e0de3573f]

    CheapMiao

    Oh, I know, I need a NavigationRegion2D. I just thought tilemap has baked nav automatically.

    I know your issue, print_debug(nav_agent.is_target_reachable()) return false but nav_agent.get_next_path_position() return a valid pos. You may post a issue?