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Asked By
javrocks
I would like to get the global_position of a node Player in my Main.tscn and i would like to access it from another scene Projectile.tscn but this code dosen’t work
extends KinematicBody2D
onready var player = get_tree().get_root().get_parent().get_node("Player")
var target = null
func _physics_process(delta):
target = player.position
print(target)
Hi
are you sure that the player node is already in the tree? When this onready event fires the player maybe not ready yet.
klaas | 2021-09-21 17:09
The player node is a node in my Main.tscn idk if its in the tree
I have tried using:
extends KinematicBody 2D
var player = get_node("/root/Main.tscn/Player"), and
var player = get_tree().get_root().get_node("Main.tscn/Player")
Man, this is a mess
You should GIVE the players position to the scene that depends on it, not force it to obtain this information by itself. Your scene should contain some menager node, with player as its child, and when it would create projectiles, it would know players position as a parent, and would give it to projectiles. Another way is to menage those thing with signals, for example every time player presses shoot button, it emits signal with his current position and direction, so another node can create bullets from those information
If you were to use a signal to send the players position how would the projectile
receive it in another scene
How do you send a signal across a scene??
javrocks | 2021-09-23 22:40
Function emit_signal(variant) always emits across the scenes, as long as they all belong in one Scene tree. It is best to use Autoload and call it to emit signal. Every node who is interested in this signal, will have to use function connect() in its ready function. Finally interested node will have its own function for reacting on this signal.
Tell me what do you want to do in your game with this player, position and projectile, and I will show You how You should structure signalling code.
Inces | 2021-09-26 07:02
I don’t know if it is possible to store the players position in a signal but i would like the player to emit a signal containing its global position and the in my Enemy scene i would like to connect to that signal and use the player position as a target for the enemies
Ok, so what you really want to do it pass a reference of one sibling object to another.
Your approach of trying to directly reference the object in the tree is very brittle, objects and scenes can be added and removed from the tree at any time which will break the hard reference in the code. My personal rule of thumb is only to use hard references within scenes and even then to have a Path set in the editor; so if you rearrange nodes it won’t break. Even if it does break, if the problem is within a single scene, ironing out the references generally isn’t hard.
The simplest/laziest/dirtiest approach between scenes is just to have a singleton with a variable/array/dictionary. Then when you make the target it can add itself to the list in the ready method - eg singleton.target.append(self) - and when it dies it can remove itself. Global variables like this are frowned upon by seasoned coders but sensible, very limited use that you’re 100% on top of can be easy and effective causing zero problems.
A variation on the above is having a “world” or “level” scene which has variables/arrays/dicts containing the child objects within it. At least then you’re limiting scope to some extent.
As mentioned above, signals are a great option but you don’t want to be sending one every frame.
My personal preferred approach is to pass the object via the game event that made it necessary. So if you’re using a raycast / collision / mouse click / etc to decide what the target is then pick up the target object when this happens. Godot generally just hands you an object reference in the event.
So, there are many ways to do it, you just need to find a way that doesn’t end in spaghetti code and dependencies; the rule of thumb is that every scene should run individually without errors.
