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Attention | Topic was automatically imported from the old Question2Answer platform. |
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Asked By | malraux42 |
Hello all!
I have a Scene (called Scaffold) that instantiates several other Scenes (called Blocks) when it enters the the tree. The Scaffold holds a Conveyor scene whose job it is to move Blocks towards positive z-index while it runs – a typical auto-moving scenery setup where each Block holds things like obstacles and traps and the player stays in the center. Block has a method called set_block_index that registers which block it is in the Conveyor and initializes its position based on that.
The problem I’m having is that set_block_index can’t be called from Scaffold.gd during this setup execution as it will throw “Invalid call. Nonexistent function `set_block_index` in base ‘Spatial’.”. I can get it to work by calling the method via call_deferred, but I’m unsure of the ramifications of calling the method in such a fashion.
So there are a few things I’d like to understand here:
- Why can’t a method defined on a Scene script be called externally?
- Why is the call not found in the base Spatial when it should be looking in
Block.gd? Perhaps that’s just saying it didn’t find it in either and not until it failed the fallback did it throw the error.
Here’s the code in question:
# Scaffold.gd
var starting_block_scene = preload("res://StartingBlock.tscn")
var block_scene = preload("res://Block.tscn")
var current_block_index = 0
func _enter_tree():
setup_blocks()
func setup_blocks():
add_block(starting_block_scene)
add_block(block_scene)
func add_block(scene):
var block = scene.instance()
$Conveyor.add_child(block)
# Calling `set_block_index` immediately causes:
# "Invalid call. Nonexistent function `set_block_index` in base 'Spatial'."
block.set_block_index(current_block_index)
# Calls `set_block_index` correctly.
# block.call_deferred("set_block_index", current_block_index)
current_block_index += 1
extends Spatial
var block_index = 0
const block_length = 40
func set_block_index(index):
block_index = index
# Do other initialization here based on the block index...
translation.z = -index * block_length
Thanks for your help in advance!