Misunderstanding about duplicates and scripts.

jbskaggs

I thought if duplicate nodes ran the same script that had a random function that each duplicate would then have a different random result. But it does not appear to be the case.

My thinking was that each duplicate even though they shared resources would run the script individually.

Could I have a little clarification on this?

Gowydot

I could be wrong but maybe it has something to do with the way you set up the random function, like normally a random function would result in the same pattern of randomness or something. There is a way to make it truely random individually but I don't remember where I read it from anymore. It's possible from Godot doc so maybe you can check there first. Sorry for not much help.

jbskaggs

OK here is what happened and here is what I ended up doing:

I have a node2d that had 1 sprite and several labels that were randomly generated. I duplicated this 3 times with ctrl d in editor. When I ran it if the script of all 3 copies was the same script (it could be different from the original) just all three copies had to use the same script. If I tried different scripts only the first duplicate used the script. The other two would not even read their attached script.

If I used same script all 3 copies would be identical. But then why could the original have a different script than the copies- but all the copies had to have the same script?

I could not figure out how to make it function different.

So I created 3 inherited scenes of the original and that worked.

But I really do not understand the logic of this at all.

Gowydot

Have you tried ticking script local to scene (on Inspector > Resources) and see how that works? (I haven't try it myself)

xyz

Make a minimal project that reproduces the problem. Also, print is your friend.

Comment out all code and just print a single random number from script's _ready(). Does it output 3 different numbers or 3 same numbers? If they are same, how do you generate your random numbers? If the script creates a new RandomNumberGenerator object, each instance will be initialized with the same default seed, producing the same sequence of pseudo-random numbers. To avoid this, call RandomNumberGenerator.randomize() after object creation to re-initialize it with a random seed.

jbskaggs

@xyz said: Make a minimal project that reproduces the problem. Also, print is your friend.

Comment out all code and just print a single random number from script's _ready(). Does it output 3 different numbers or 3 same numbers? If they are same, how do you generate your random numbers? If the script creates a new RandomNumberGenerator object, each instance will be initialized with the same default seed, producing the same sequence of pseudo-random numbers. To avoid this, call RandomNumberGenerator.randomize() after object creation to re-initialize it with a random seed.

Is RandomNumberGenerator.randomize() different than randomize() because i had that in func ready: ?

jbskaggs

@Gowydot said: Have you tried ticking script local to scene (on Inspector > Resources) and see how that works? (I haven't try it myself)

Actually not on this case I did not. But thats a good idea. I dont know if it affects randomizing though.

xyz

randomize() is a global function. It only affects global rand*() functions. RandomNumberGenerator.randomize() is a method of RandomNumberGenerator object. It only affects its own seed. Are you using global random generation functions or RandomNumberGenerator object methods to generate the numbers? What happens when you print a single number from _ready()?

jbskaggs

I am using the randi function. I will test it more tomorrow as I am getting tired. But to you mean once or repeatedly print the number? On the original I would get unique numbers each time- but the copies always had the same numbers. I have not used the randomnumbergenerator.randomize() before.

Good night Ill talk more morrow

xyz

Once. If you have 3 script instances it should print 3 numbers in total. Are those 3 numbers same or different? If they are different the problem is somewhere else, not it random number generation.

jbskaggs

@xyz said: Once. If you have 3 script instances it should print 3 numbers in total. Are those 3 numbers same or different? If they are different the problem is somewhere else, not it random number generation.

@TwistedTwigleg @cybereality

I created a blank project. I created a node 2d. Created a Label and attached one script. Created one button.

extends Label



# Called when the node enters the scene tree for the first time.
func _ready():
	randomize()
	text=String(randi() %10)




func _on_Button_pressed():
	randomize()
	text=String(randi() %10)

I then Ctrl -D duplicated the label 3 times.

On first run:

1, 7,4, 3 1st pressed button: 4, 7,4,3 2nd pressed button: 2,7,4, 3 3rd pressed button: 9,7,4, 3 4th pressed button: 9,7,4, 3 5thd pressed button: 5,7,4, 3

On2nd run:

1,9,4,5 1st pressed button: 9,9,4,5 2nd pressed button: 2,9,4,5 3rd pressed button: 8,9,4,5 4th pressed button: 3,9,4,5 5thd pressed button: 8,9,4,5

other runs were the same way.

The original changes.

but the 3 duplicated nodes only change upon first run func ready():, they do not change again.

Could you check and see if this does same thing for you or if this is a bug?

xyz

You need to connect the button signal to duplicates. Signals work with objects, not with classes. So you need to connect all objects that want to receive the signal, even if they have the same script class attached. Connection needs to know the method and the object.

Also, always use print() instead of labels for checking values. Labels won't differentiate between value not changing and value not outputted at all, a distinction that's quite important in debugging.

Had you used print() for this problem you would have noticed that signal handlers didn't get called at all for label duplicates, meaning there's no connection. Labels can misled you into thinking that rng is generating the same numbers while in fact it's just previous output stuck in label text and never again refreshed because code that's supposed to do it never gets executed.

cybereality

Also, you only need to call randomize() once total when the game starts (like on a root script, not in the child nodes). This just seeds the random (starts the first random number randomly, if you don't call it then every time you run the game you'll get the same numbers in the same order). So there is no benefit to calling it more than once (though it won't really hurt things either, it's just unnecessary).

jbskaggs

@xyz said: You need to connect the button signal to copies. Signals work with objects, not with classes.

Also, always use print() instead of labels for checking values. Labels won't differentiate between value not changing and value not outputted at all, a distinction that's quite important in debugging.

Had you used print() for this problem you would have noticed that signal handlers didn't get called at all for label copies, meaning there's no connection. Labels misled you into thinking that rng is generating the same numbers while in fact it's just previous output stuck in label text.

I dont understand what you mean by attaching signals to copies of the labels. There is only one button and one signal.

jbskaggs

Ok the behavior with the labels are the same after I changed this script. The output does show the random change. So why are the labels not changing?

extends Label

var text1=0
var text2=0
var text3=0
var text4=0

# Called when the node enters the scene tree for the first time.
func _ready():
	randomize()
	text1=String(randi() %10)
	text2=String(randi() %10)
	text3=String(randi() %10)
	text4=String(randi() %10)


func _process(delta):
	text=text1
	$'../Label2'.text=text2
	$'../Label3'.text=text3
	$'../Label4'.text=text4

func _on_Button_pressed():

	text1=String(randi() %10)
	text2=String(randi() %10)
	text3=String(randi() %10)
	text4=String(randi() %10)
	print(text1)
	print(text2)
	print(text3)
	print(text4)

jbskaggs

Ok I moved the script to the Node2d and edited for paths and it now works.

But I would like to understand why and please forgive my thickness.

xyz

@jbskaggs said:

@xyz said: You need to connect the button signal to copies. Signals work with objects, not with classes.

Also, always use print() instead of labels for checking values. Labels won't differentiate between value not changing and value not outputted at all, a distinction that's quite important in debugging.

Had you used print() for this problem you would have noticed that signal handlers didn't get called at all for label copies, meaning there's no connection. Labels misled you into thinking that rng is generating the same numbers while in fact it's just previous output stuck in label text.

I dont understand what you mean by attaching signals to copies of the labels. There is only one button and one signal.

If you want button to send a signal to each label, a connection must be made for each label. Currently you've connected only the original label, so only it gets the signal callback. You need to connect each duplicate too. One signal can have multiple connections.

jbskaggs

@xyz said:

@jbskaggs said:

@xyz said: You need to connect the button signal to copies. Signals work with objects, not with classes.

Also, always use print() instead of labels for checking values. Labels won't differentiate between value not changing and value not outputted at all, a distinction that's quite important in debugging.

Had you used print() for this problem you would have noticed that signal handlers didn't get called at all for label copies, meaning there's no connection. Labels misled you into thinking that rng is generating the same numbers while in fact it's just previous output stuck in label text.

I dont understand what you mean by attaching signals to copies of the labels. There is only one button and one signal.

If you want button to send a signal to each label, a connection must be made for each label. Currently you've connected only the original label. You need to connect each duplicate too. One signal can have any number of connections.

A button can have more than one pressed signal to more than one thing? I did not know that. Let me check that.

jbskaggs

Ok I understand now. Thank you for teaching me. For almost two years I ever knew a control could have multiple signals of same action. And I now understand why I had the problems. And I understand now why instancing scenes ends up faster.

xyz

Any scripted object can "subscribe" to any signal. It just needs to make the connection. Signals are like mailing lists. Making a connection is like subscribing to that mailing list.

Button will emit any of its signals to whoever is interested in receiving it. That's the whole point of signals.