Keeping the Inventory across Scenes

[Hannes_Johannes]

Godot Version

4.3.stable

Question

I’m relatively new to Godot and I’m currently working on a project for school. I’m building a 2D game where you have different views, like in the Cube Escape games by Rusty Lake. You move around with arrows that changes the scene by using change_scene_to_file(). Then I have an Inventory Scene at the bottom of the screen. The Inventory should always be visible, also when I change the Scene. I then tried to reference the scene via a Singleton, so I could paste it in every Scene, because the Items that you can collect in the different Scenes should obviously stay in the Inventory as well. This is the exact code I used:

In the first Scene:

if Global.inventory_ref == null:
Global.inventory_ref = %Inventory

The button that changes the scene:

func _on_area_2d_input_event(viewport: Node, event: InputEvent, shape_idx: int) → void:
if Input.is_action_just_pressed(“click”):

	Global.inventory_ref.get_parent().remove_child(Global.inventory_ref)
	get_tree().root.add_child(Global.inventory_ref)

	get_tree().change_scene_to_file("res://level_1_rechts.tscn")

An finally in the upcoming Scene (level_1_rechts in this case):

func _ready() → void:
if Global.inventory_ref.get_parent() != self:
get_tree().root.remove_child(Global.inventory_ref)
add_child(Global.inventory_ref)

The problem is that this version didn’t really work, because the items in the inventory just randomly disappeared and reappeared when changing the Scenes. I also have to admit that ChatGPT wrote this and it seems pretty sketchy to me.

I also tried asking ChatGPT how to approach this in a different way, so I tried making the Inventory itself an Autoload, but that didn’t work either because it always was visible for just one frame and then disappeared for no apparent reason.

I feel like there is a simpler way, because I see this concept in many games. So how would do this?

[rpahut]

What’s “%Inventory” ? I feel this is kind of relevant.

Anyway, if you want to do it with singletons Godot has a special thing for that:

Singletons (Autoload)

But there is also a way to switch out just the part of the node tree containing the level while keeping the inventory:

Change scenes manually

[that_duck]

@rpahut

What’s “%Inventory” ? I feel this is kind of relevant.

That is a unique name reference for the current scene tree.

Given the OP isn’t complaining about null errors, it is likely present on the tree.

[gertkeno]

Try making an Inventory scene global, this could display the inventory at the bottom, not just a script to hold data.

Here’s how I set up an Inventory scene, since the root node has a script I can also access it’s functions through the global identifier. A CanvasLayer for the root node will work better for your 2D game.