Invalid get index global position (on base previously freed) error

[ice_dev]

Godot Version
v4.1.2.stable.official

extends CharacterBody2D

@export var movement_speed = 40.0

@onready var planta = get_tree().get_first_node_in_group(“planta”)
@onready var sprite = $Sprite2D

func _physics_process(_delta):
var direction = global_position.direction_to(planta.global_position)
velocity = direction*movement_speed
move_and_slide()

if direction.x > 0:
	sprite.flip_h = false
	
elif direction.x < 0:
	sprite.flip_h = true

func _ready():
$lil.play(“move”)

func _on_area_2d_area_entered(_area):
if _area.is_in_group(“planta_area”):
$lil.play(“attack”)

func _on_area_2d_area_exited(_area):
$lil.play(“move”)

There are several plants in the project and when the enemy destroys the plant the project collapses

[trizZzle]

Previously freed means that the object you are getting the global position from was deleted previously (when you killed it/called queue_free() on it).

You can check if an object still exists with is_instance_valid(object)

func _physics_process(_delta):
    if is_instance_valid(planta):
        # movement code
    else:
        # code to find new planta 

[ice_dev]

Friend, thank you very much. I don’t know how to make the enemy look for another plant. I don’t know if you could help me with that?

[trizZzle]

The same way you did it before should work:

@onready var planta = get_tree().get_first_node_in_group(“planta”)

func _physics_process(_delta):
    if is_instance_valid(planta):
        # movement code
    else: 
        planta = get_tree().get_first_node_in_group(“planta”)

[ice_dev]

Hello, I wrote the code and all these errors appear
Invalid character ““” (U+201C).
Invalid character “”” (U+201D).
(STANDALONE_EXPRESSION):Standalone expression (the line has no effect)

[trizZzle]

Use" instead “ for your strings. For example: “planta”
I copied them from your example.

For what code does it show: (STANDALONE_EXPRESSION):Standalone expression (the line has no effect)?

EDIT: Not sure why this forum converts " to the others.

[ice_dev]

Now it’s fixed a little, it just keeps giving the error

(STANDALONE_EXPRESSION):Standalone expression (the line has no effect)

It says it is on line 20 and on line 20 is the move code address. I don’t know if that’s why.
I’ll leave you the code again just in case

@export var movement_speed = 40.0

@onready var planta = get_tree().get_first_node_in_group(“planta”)
@onready var sprite = $Sprite2D

func _physics_process(_delta):
var direction = global_position.direction_to(planta.global_position)
velocity = direction*movement_speed
move_and_slide()

if direction.x > 0:
	sprite.flip_h = false
	
elif direction.x < 0:
	sprite.flip_h = true
	
if is_instance_valid("planta"):
	direction
else:
	planta = get_tree().get_first_node_in_group("planta")

func _ready():
$lil.play(“move”)

func _on_area_2d_area_entered(_area):
if _area.is_in_group(“planta_area”):
$lil.play(“attack”)

func _on_area_2d_area_exited(_area):
$lil.play(“move”)

[trizZzle]

@ice_dev

if is_instance_valid("planta"):
	direction

direction alone doesn’t do anything, hence the error.

It should look something like this (tabs/spaces are probably wrong because I copied your unformated code):

func _physics_process(_delta):
    # Run movement code if planta exists
    if is_instance_valid(planta):
       var direction = global_position.direction_to(planta.global_position)
       velocity = direction*movement_speed

       if direction.x > 0:
	      sprite.flip_h = false	
       elif direction.x < 0:
	       sprite.flip_h = true
       move_and_slide()
    # Find new planta if it doesn't exist anymore
    else:
          get_tree().get_first_node_in_group(“planta”)

[ice_dev]

The game no longer crashes when the enemy destroys the plant but the enemy doesn’t move so I put a move_and_slide on the else but the enemy doesn’t go towards the plant until it looks like it’s going to the opposite side.

[trizZzle]

    else:
          planta = get_tree().get_first_node_in_group("planta")
          print(planta)

What does it print in output? Did it find a new plant?

EDIT: It should be:
planta = get_tree().get_first_node_in_group("planta")

Your forgot planta =

And you don’t want to put move and slide in else, because you don’t want to move if there is not plant to walk to.

[trizZzle]

@ice_dev

but the enemy doesn’t go towards the plant until it looks like it’s going to the opposite side.

That’s because you didn’t find a new plant and you didn’t update the velocity of your character. When you call move_and_slide() it will use the velocity you last set. And in your case it was the direction to your last plant.

[ice_dev]

thank you very much the code now thank you very much for your patience

[trizZzle]

Hey, no problem! Have fun with Godot!