i was making a game and want the enemy to follow the player, one that’s already spawned in doesn’t crash, but when a new one spawns in it crashes
extends CharacterBody2D
@onready var dir
# Called when the node enters the scene tree for the first time.
func _ready() -> void:
look_at(%player.global_position)
# Called every frame. 'delta' is the elapsed time since the previous frame.
func _process(delta: float) -> void:
dir = Vector2.RIGHT.rotated(rotation)
position += dir *delta*100
Bro if you’re going to want people to help you you’re going to have to put a little more effort into posing your question. The title is useless. Your question is unclear. You didn’t even bother to look at which verse you’re using.
First things first, next time put what version of the engine are you using, what type of game/program are you doing, learn how to debug (i put a material in the third link in the references), and see the guidelines for posting in the “Help” forum: Posting guidelines in #Help channel.
The characterbody2d is usually for playable aspects of the game, not for the computer to use, second, to access a character body 2d nodes direction and speed the way you are doing without taking into account the function move_and_slide() of the same node leads to some janky behavior.
If you want a node to access those attributes, I recommend RigidBody2D.
Also, I think you are doing a top down style of game, if you are you should be using collisionobject nodes and program the movement from zero.
Next, the @onready editor function all it does is declare variables while the function _ready() runs, if you declare something and dont give it a type or a value and then accessing it the very next frame without proper security checks to ensure the value isnt Null it may crash in most cases.
To solve this what I would do is the next:
First the enemy scene should roughly look like this:
RigidBody2D/CharacterBody2D
|
--Sprite2D/AnimatedSprite2D
Also very important that you have a GameManager, check the fourth link in references.
In the code of your character it should send the information of its position to its parent or the GameManager, and in the game manager there should be a simple function called “get_player_position()” and in your enemy code it should look like this, (i am making the code for characterbody2D but I really recommend the RigidBody2D node):
const MAXIMUM_MOVEMENT_SPEED:Vector2 = Vector2(50,-50)
var enemy_direction:Vector2 = Vector2(0,0)
var known_players_position:Vector2
func _process(delta: float)→void:
known_players_position = GameManager.get_player_position()
#If it is negative it means the player is on the right, if its positive it means the player is on the left
enemy_direction.x = position.x – known_players_position.x
#if the value is more than a 100, limit it to a 100
enemy_direction.x = clamp(enemy_direction.x, -100, 100)
#if it is negative it means that the player is below the enemy,
#if it is positive it means the player is above the enemy
enemy_direction.y = position.y - known_players_position.y
#if the value is more than a 100, limit it to a 100
enemy_direction.y = clamp(enemy_direction.y, -100, 100)
velocity.x = MAXIMUM_MOVEMENT_SPEED.X * enemy_direction.x
move_and_slide()
This code is for a linear side scroller but it gives an idea.
You should be able to see in the error message what the problem is. Probably the enemy scene does not have a proper reference to player. Does it say anything about not finding property global_position on a null instance?
Even if you don’t understand what the error messages mean it would be useful to include it for anyone trying to help you.
You dont need dir to be onready as you set it to a value in process before ever using it. Not important but just a good habit to avoid having unnecessary exports, onreadys etc as the script will be easier to glance through later when you have maybe twenty variables on the top of the script.
