Raycast collision needs to spawn a new raycast from an Area2D problem.

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Raycast collision needs to spawn a new raycast from an Area2D problem.

BingBong

not sure how to go about this….

I have a world scene with (so far 3) instances of a scene with an area2D , and an instance of a raycast scene for a light beam, the lightbeam stops when it hits an area2D. On colliding this area2D, I want a new lightbeam to project from this area2D, on to the next etc… (at the moment this second identical Raycast/Line2D scene only differs in that the first lightbeam direction is controled by mouse position for testing)

The scene tree is as follows

World Node2D < has the Area2D in it Node2D2 < ditto! Node2D3 Lightbeam

1st problem, At scene runtime, the lightbeam is not colliding with anything to start with, so im getting an error…

Invalid call. Nonexistent function 'queue_free' in base 'PackedScene'.

but as I want the second lightbeam to disapear when the first one stops touching the Area2D, I THINK this code is correct…. Just not for at the start of running the World scene itself.

This is the script thats attached to the World scene…

extends Node2D

onready var scene = load("res://otherstuff/2ndLightBeam.tscn")
onready var node_pos = Vector2()

func _ready():
	pass

func _physics_process(delta):
	if $LightBeam.is_colliding():
		node_pos.get_node("Node2D").position
		scene.instance()
		scene.position = Vector2(node_pos)
		get_parent().add_child(scene)
	
	elif $LightBeam.is_colliding() == false:
		scene.queue_free()

2nd problem would be that it would always be looking to spawn from the Node2D, and not the next one, Node2D2, or the next one, etc, and they wouldnt necesarily be collided in any particular order.

Any advice welcomed, I have reached the edge of my somewhat flat Godot world! Falling off is not an option :)

TwistedTwigleg

1st problem, At scene runtime, the lightbeam is not colliding with anything to start with, so im getting an error… Invalid call. Nonexistent function 'queue_free' in base 'PackedScene'.

This error is happening because scene is set to load("res://otherstuff/2ndLightBeam.tscn"), which is a loaded packed scene that you can instance, but not a scene itself. You will likely want to make a new variable called something like scene_node and then check against this to see if you have spawned/instanced one:

extends Node2D
onready var scene = load("res://otherstuff/2ndLightBeam.tscn")
var scene_node = null
onready var node_pos = Vector2()

func _ready():
	pass
func _physics_process(delta):
	if $LightBeam.is_colliding():
		node_pos = get_node("Node2D").position
		scene_node = scene.instance()
		scene_node.position = Vector2(node_pos)
		get_parent().add_child(scene_node)
	elif $LightBeam.is_colliding() == false:
		if scene_node != null:
			scene_node.queue_free()

Then that should fix the 1st problem. I also made a couple really minor fixes to fix some little issues (like assigning node_pos) but nothing major.

For the second problem, what you'll need to do is get a reference to the node the LightBeam collided with and then instead of using get_node("Node2D").position, instead you'd want to use a reference to the last collided node instead. Something like this might work:

extends Node2D
onready var scene = load("res://otherstuff/2ndLightBeam.tscn")
var scene_node = null
onready var node_pos = Vector2()
var last_collider = null

func _ready():
	pass
func _physics_process(delta):
	if $LightBeam.is_colliding():
		if $LightBeam.get_collider() != null:
			last_collider = $LightBeam.get_collider()
		else:
			last_collider = null
		
		if (last_collider == null):
			node_pos = get_node("Node2D").position
		else:
			node_pos = last_collider.position
		scene_node = scene.instance()
		scene_node.position = Vector2(node_pos)
		get_parent().add_child(scene_node)
	
	elif $LightBeam.is_colliding() == false:
		if scene_node != null:
			scene_node.queue_free()
			last_collider = null

BingBong

Dude, thats superb! Good to know I was on the right track. I'll try impliment this tomorrow (getting on for 4am and eyes are getting heavy!), but I see what your getting at, it hadnt occured to me I needed to check for the scene first, and for the second issue, actually HOW to pass in which nodes been collided with.

Most helpful, thanks! I might just get something finished for the godot jam in time!! :)

BingBong

Hmm, ok, so I changed a bit of code and have the first problem (almost) sorted, it didnt quite work as expected….

if scene_node != null: caused an error, took a while to figure out….

if is_instance_valid(scene_node): …is the correct way to check that.

It then worked, BUT, hundreds of nodes were created on a delta basis, not good! I changed things around to make sure only one node it created, I THINK that this is what its now doing, but not 100% sure!


extends Node2D

onready var scene = load("res://otherstuff/2ndLightBeam.tscn")
var scene_node = null
onready var node_pos = Vector2()
var has_instance :bool = false


func _physics_process(delta):

	if $LightBeam.is_colliding() and has_instance == true:
		pass
		
	if $LightBeam.is_colliding() and has_instance == false:
		print("colliding")		
		node_pos = get_node("Node2D").position
		scene_node = scene.instance()
		scene_node.position = Vector2(node_pos)
		add_child(scene_node)
		has_instance = true
		print(scene_node, "... scene entered")

	elif $LightBeam.is_colliding() == false:
		print("not colliding")
		if is_instance_valid(scene_node):
			scene_node.queue_free()
			has_instance = false
			print(scene_node, "... is free")

I was pointed in the right direction with your answers tho!!

HOWEVER, this creates a problem I hadnt forseen… as we are detecting when the raycast hits an Area2D, the new instanced scenes are instantly detecting the Area2D on spawning as they are at the position of those nodes they collide with (where I want them!), and as I suspect, it immediately is queue_free’d….

In hindsight, seems this is basicly the laser and lens-companion-cube mechanics in portal im trying to create!

Now as these light beams are going to be colliding with and spawning from throughout many different Area2Ds im proper stuck if the raycast is deleted before it gets a chance to raycast! How do I get these Raycast lightbeams to both detect AND not detect the Area2Ds!??

Heres a pic for visual reference, the beam hits the first godot head(which can rotate) then spawns the new lightbeam which hits the next godot head, etc etc....

Dammit, I fell down the rabbit hole…