NullRefeferenceException Error

[shy bridge]

line 19

[vivid sundial]

line 19 is
var selectionTransform = hit.transform;, yes?

[shy bridge]

oh ya i forget discord doesnt show tghe lines

Ray ray = Camera.main.ScreenPointToRay(Input.mousePosition);

[vivid sundial]

that is line 19?

[shy bridge]

yes

[vivid sundial]

to me, it seems that Camera.main is undefined

this is surprising, but you may have multiple cameras in the scene, which could cause that to freak out

it is probably better to directly define a camera variable, and reference that instead

[vivid sundial]

oh shoot, I didn't even think to look at the video, where you clearly show line 19, apologies

[little hearth]

Is the camera attached to the Player object, because i don't even see a camera object?
And if it is, make sure it has the "MainCamera" tag

Actually, i don't see the lines for the viewport of the camera at all anywhere.... is it so simple you've deleted the camera? 😄

[shy bridge]

what i didnt deletethe camera

[little hearth]

Well, it's not in your hierarchy, unless you have it as a child of your Player object

[vivid sundial]

ah, good catch, this is probably the culprit

the MainCamera tag, that is

[little hearth]

NullExceptionError troubleshoot for me always ends up being one of these two:

1. Does the object exist?
   Yes? Move to two
   No? Add it
2. Is the reference to the object correct?
   Yes? (usually never if it's Yes on previous)
   No, fix the reference so it catches the object correctly.

[shy bridge]

opk ill try that

[vivid sundial]

could you just use a serialized reference, like I originally suggested?

it is probably better anyways, as then you don't have to rely on a single camera

[little hearth]

I mean... i have a vague feeling he doesn't even have the camera there at all, since i can't see it in the hierarchy, and i don't see the viewport lines coming from the character so i get a feeling it's not attached to the player, wich is the only not-expanded object in the hierarchy

[vivid sundial]

the camera is a child of Player, I guarantee it

[little hearth]

So... the object in the scene is not the player then i assume?

[vivid sundial]

which object in the scene, exactly?

[little hearth]

Ah i guess the ball is "Sphere"

The player is nowhere close to where he's looking in the scene.

I thought it was a capsule, wich most people use as "Player" early on lol

[shy bridge]

heres the video

https://www.youtube.com/watch?v=_GzSfnJNNI4&list=PLtLToKUhgzwnk4U2eQYridNnObc2gqWo-&index=4

[little hearth]

But i'd probably still make a proper reference in the code for the camera. Either by tag "MainCamera" or by child of player, or just by a public field reference it in the inspector

Make sure i can always see the reference properly.

@shy bridge Is your Camera a child of your Player Gameobject? And does it have the MainCamera tag?

[shy bridge]

ill look

[vivid sundial]

yes, we understand
we both have solutions to your problem, could you try one real fast?

do you understand what a NullReferenceException is? it may help you understand what we're instructing you to do

[shy bridge]

now it does

[little hearth]

So, like this i assume?

[shy bridge]

no

[little hearth]

TL;DR a NullReferenceException is when your script can't find a GameObject you're telling it to use, so there reference of it is null

aka empty

[shy bridge]

oh

so its not picking up a object

[vivid sundial]

kinda?

[little hearth]

@vivid sundial It'd be the "nub" explanation

There's more to it

Like, i don't even know the full extent of things like that either 🤷‍♂️

But i feel like it's general rule of thumb that either your code can't find the object reference, or the object actually doesn't exist

[vivid sundial]

it is simply indicative of being unable to find a reference to an object

not necessarily a GameObject, just any non-primative type

[little hearth]

Well, true

Can be anything that is null when it shouldn't be, basically. 🤷‍♂️

@shy bridge Did you say you didn't have the MainCamera tag, and you do now?
Did that help?

[shy bridge]

ya

[vivid sundial]

ok, good

[shy bridge]

i still get the error tho

[little hearth]

Solid

Oh

[vivid sundial]

oh

how did it help then?

[little hearth]

I think he just said yes to the tag question

[shy bridge]

one c\sec

now im getting this error

interaction_text.text = selectionTransform.GetComponent<InteractableObject>().GetItemName();

null

https://tenor.com/view/im-dead-dead-bruh-skeleton-dead-bruh-skeleton-dead-im-dead-bruh-gif-26854866

[vivid sundial]

yeah, ok, that's because not every object that the ray collides with has a InteractableObject component

you have to filter the results somehow

[shy bridge]

ok

[vivid sundial]

you could do this in a few ways

1. Guard the target code with a null check
2. Tag your objects, and then guard with a tag check
3. Put all of your interactables on a separate layer, and use a layer mask on the raycast

[little hearth]

I just checked in the guide, it's wrapped in an if statement so unless i'm being dumb atm, it shouldn't toss an error

[shy bridge]

ill test it

damn i stil get it

[little hearth]

This is the awesome but also horrible thing about tutorials. if you follow every step exactly, it works. If you miss a tiny step somewhere, it becomes real annoying to find it, especially in the beginning of your game-dev experience before you've started getting used to what tosses errors

[vivid sundial]

oh shoot, didn't even realize that

ok, then interaction_text must be undefined

[little hearth]

I'm wondering... if it's issues with the reference to interaction_text

[vivid sundial]

also, why is this tutorial using snake case for c#?

that is quite dubious.

[little hearth]

What's snake case

I've never heard that before lol

[vivid sundial]

variables_written_like_this

[little hearth]

Oh

Some people like it

Some people live and die on that hill lmfao

ALWAYS UNDERSCORE EVERYTHING

[vivid sundial]

yes, however languages have standards

people not willing to put down their preferences for those standards are... questionable...

[little hearth]

Truuueee, but technically this is user-specific.

You can name a variable asdfnizsdnfuisduifg if you prefer that

or 1896525

[vivid sundial]

no, you can't name a variable 1896525

[little hearth]

Probably not, but you know what i mean

You've quite some freedom to name variables like you want

Some bastard i saw who did a movement script, used "num" "num1" "num2" etc up to num5, in a whole movement script.... i figured out in the end that num and num1 was X and Y direction of mouse 🤦‍♂️

@shy bridge Can you show/tell what you're doing when the error is tossed, and paste the whole script?

[vivid sundial]

ok, I'm really starting to question this tutorial...

wrong naming conventions, using GetComponent in Start()

bro's probably going to use a Find method in a sec here

[little hearth]

I think you're going to hate my scripts

lmfao

[vivid sundial]

oh, and using public, not [SerailizeField]

[little hearth]

hides

I've actually used both. But in my defense, atm, i'm just throwing something together that sorta works, before i start refining it.

[shy bridge]

here let me make a video

[vivid sundial]

actually though, I'm really curious about who exactly began teaching people to use public like that

[little hearth]

@vivid sundial 🤷‍♂️ I've gone around most my scripts and set most to private and started referencing a lot by script rather than in the inspector. But i still have a bunch of publics left.

But i'm definitely doing GetComponents in my Start() methods a lot

Is one example.... hides

[vivid sundial]

nooooooooooo

[little hearth]

IT WORKS

[shy bridge]

NIO wAYYYYYYYYYY

[vivid sundial]

no, bro, you're using a find method... that's the real issue here

[little hearth]

@shy bridge Sorry i was talking to Wormy about that. BUT. In your case.....

Wheres the text component in the hierarchy?

on the Canvas?

[vivid sundial]

*proceeds to show the player component and not the component in question*

[little hearth]

@vivid sundial Is it just me that find the text referencing a bit strange in the script?

[shy bridge]

wdym

you mean the scripts

[vivid sundial]

as I've told you, I believe the issue to be a missed reference to interaction_Info_UI

so I wanted to see if that was defined in the inspector

[vivid sundial]

the inspector...

that's the heirarchy

[little hearth]

You've a text object somewhere in your hierarchy. The Text interaction_text; variable that you're trying to reference via interaction_text = interaction_Info_UI.GetComponent<Text>();

but there's neither private or public before Text interaction_text; wich irks me a bit, but idk if it's doable that way.

[vivid sundial]

hey, by the way, you can create in-line code blocks by encapsulating text with the diacritic mark

[little hearth]

What mark is that

[vivid sundial]

so, like `code here`

[little hearth]

OH

Cool.

[shy bridge]

oh i feel dumb

the interaction_info_UI was the text

[little hearth]

Soooo... you figured it out and it works now? 😄

[shy bridge]

https://tenor.com/view/im-dying-jake-adventure-time-gif-11704783

its not

[little hearth]

@vivid sundial Btw, since you didn't like my Find method... what'd you do? I know that some people out there tend to be "Never use Find by tag!" for example, but... it works

[vivid sundial]

[]find

ugh, the brackey's bot has changed

[little hearth]

@shy bridge Okay so... there's an issue with the reference.
The gameobject you have the script attached to, show the inspector. Aka this part:

@vivid sundial ngl, i use a lot of Find by tag.... because it works for me cross-scene and i use a lot of instantiated prefabs

[cursive perch]

Don't use Find methods!

Find methods in Unity are an often-tempting solution to referencing a scene object. However, there is always a better solution.
Whenever you call a Find method, Unity must traverse your entire scene hierarchy and check every single object until it finds a match; and the methods which return arrays will always traverse the entire hierarchy regardless.
This is inefficient! It means that the more objects you add to your scene, the slower these methods become; and it gets even worse if you are calling them multiple times.

A non-exhaustive list of Find methods to avoid:
https://docs.unity3d.com/ScriptReference/GameObject.FindWithTag.html
https://docs.unity3d.com/ScriptReference/Object.FindObjectsOfType.html
https://docs.unity3d.com/ScriptReference/Object.FindObjectOfType.html

To read about a better solution, type []getareference or []getref

[little hearth]

@shy bridge interaction_info_UI is not a text component?

[vivid sundial]

@little hearth , the brackey's bot can define why it's so bad better than I can, so there you go
you may have to do some reference shuffling, but there's always a better way to find references

[little hearth]

@vivid sundial Alright... i'll keep it in mind and work that in later. For now, i won't touch it since i got other things to do.

AHA

[vivid sundial]

Ahh, TextMeshPro is not Text

[little hearth]

You're using TextMeshPro! There's your issue!

Problem found

[shy bridge]

AAAAAAAAAHHHHHHHHHHHHHHHHHH

[little hearth]

So! In your code, do this:

When you reference your text

(do not write private if you reference in the inxpector, without adding [SerializeField] on the line above)

So you'd like to do, in your case:

[SerializeField]
private TextMeshProUGUI interaction_text;

[vivid sundial]

before you continue, I want to warn you against using this tutorial any further (or using one at all, but that's another argument)

it is clearly outdated (Text has been deprecated for quite some time now), and it is using very, very poor conventions, all around

[shy bridge]

im kinda new to the coding

[little hearth]

I've been in the same seat and gone through the same struggles.

I'm going to guess you're using the guide because you want to make a survival game? @shy bridge

[vivid sundial]

I understand
it may be helpful to look for a more up to date source, and a more reputable one

[shy bridge]

like a medieval type

but what do i do for this? interaction_text = interaction_Info_UI.GetComponent<Text>();

[vivid sundial]

instead of using tutorials that tell you how to make a particular game, you should try to find one that helps you with a specific problem

[vivid sundial]

what do you mean?

[shy bridge]

or for the Get for the GetComponent<Text>();

[little hearth]

@shy bridge Yeah, figured. I wouldn't want to tell you to stop per se, but a survival game is a huge undertaking and there's a lot of systems that interact with each other.
When you're new to coding, i'd (from experience) try and narrow the scope and make smaller things, to start to get used to programming.

But, if you're insistent on making a survival game. Take it step by step instead of get a tutorial for a whole "game".
Start with say Playermovement.
Then one for something else simple.
Then a new guide for some other part. Step by step etc.

@shy bridge replace Text with TextMeshProUGUI i believe is all you need to do

Wormy is going to pull his hair now, but i do the same thing here essentially:

[shy bridge]

https://tenor.com/view/kiss-good-night-gif-7093522418594608285

[little hearth]

With that extra if statement, i also get an error in the log if the reference for the component is not found for whatever reason.

[shy bridge]

thanks for the help

also one thing

[vivid sundial]

this works, but it would probably be better to use a serialized reference to that component, rather than working around its GameObject

[little hearth]

@shy bridge Get used to making null-checks like that if statement in my picture, so you can track your missing references easily.

[shy bridge]

why does my mouse have a stroke

[little hearth]

@vivid sundial I too, am an amateur and i don't know all the ins and outs. This works and the reason it is currently like this, is because i need to hard reference to a child of a prefab i instantiate into the scene.

It's ugly.... but it works

That's all i care about for the time being!

@shy bridge You mean the jump the first time you hover over the object?

[shy bridge]

ya

[little hearth]

That's a good question...

[vivid sundial]

we would need to see the code for your camera controller to answer that question

[little hearth]

I wonder....

[shy bridge]

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class PlayerCam : MonoBehaviour
{
public float sensX;
public float sensY;

public Transform orientation;

float xRotation;
float yRotation;

private void Start()
{
    Cursor.lockState = CursorLockMode.Locked;
    Cursor.visible = false;
}

private void Update()
{
    // get mouse input
    float mouseX = Input.GetAxisRaw("Mouse X") * Time.deltaTime * sensX;
    float mouseY = Input.GetAxisRaw("Mouse Y") * Time.deltaTime * sensY;

    yRotation += mouseX;

    xRotation -= mouseY;
    xRotation = Mathf.Clamp(xRotation, -90f, 90f);

    // rotate cam and orientation
    transform.rotation = Quaternion.Euler(xRotation, yRotation, 0);
    orientation.rotation = Quaternion.Euler(0, yRotation, 0);
}

}

one out of Dave/ GameDev

[little hearth]

I don't think the issue is there. Because it happens first when he hovers at the object

[vivid sundial]

[]cb

[cursive perch]

Use codeblocks to send code in a message!

To make a codeblock, surround your code with ``` (3 backticks. Click here to see where the key is)

To use syntax highlighting, add the file extension of the language you wish to highlight (cs for C#, cpp for C++)

For example:
```cs
Console.WriteLine("Hello World");
```

Produces:

Console.WriteLine("Hello World");

To send lengthy code, paste it into https://paste.myst.rs/ and send the link of the paste into chat.

[little hearth]

So, it happens upon the raycast hitting the object

[shy bridge]

{
    Ray ray = Camera.main.ScreenPointToRay(Input.mousePosition);
    RaycastHit hit;
    if (Physics.Raycast(ray, out hit))
    {
        var selectionTransform = hit.transform;

        if (selectionTransform.GetComponent<InteractableObject>())
        {
            interaction_text.text = selectionTransform.GetComponent<InteractableObject>().GetItemName();
            interaction_Info_UI.SetActive(true);
        }
        else
        {
            interaction_Info_UI.SetActive(false);
        }
    }

under this

[vivid sundial]

`, not '

[shy bridge]

thanks

[little hearth]

Perfect

[vivid sundial]

is there any other input here, or does this just happen when you hover?

no click or anything, right?

[little hearth]

But yeah, it's a bit strange it makes your camera jump, because your raycast doesn't affect your camera... 🤔 Even more strange was that when it also jumped, it didn't trigger showing the UI, but it did the next time

[shy bridge]

when i hover

[little hearth]

Did you include the

else
{
interaction_Info_UI.SetActive(false);
}

[vivid sundial]

yes, they did

[little hearth]

Oh yeah i'm blind

But then there's an issue there too, it doesn't clear the raycast

Because the label stays when he looks off of it

[shy bridge]

so its has to be the raycast system in my SelectionManager

[little hearth]

There's certainly something wonky with the raycast, but there might be something with the camera, or some other script that interacts with one or the other.

It's really hard to tell without being hands on with the project

[shy bridge]

true

[little hearth]

In this case, i say play around with it and see if you can figure it out.

The more you play around with, break, repair, scratch your head, cry, leave the PC, take a shit, come back, cry a bit more, smash it with a hammer.... the more you learn!

[shy bridge]

that is a true statement

[little hearth]

I spent 10-12 hours on an issue the other night.

I discussed the issue with someone in another discord and he just managed to shine some light on some areas i need to check

And the next day i woke up, went to PC, checked it, and i figured it out!

[vivid sundial]

ok @shy bridge
I've looked through all the stuff you've shown thus far, and I have no idea what could be causing this

[little hearth]

Yeah i'm unsure aswell, bit of a headscratcher honestly. Hence i said just... mess around with it. There's not that much to your project yet that can cause issues.

Messing around is afterall the best way to learn 🤷‍♂️

[vivid sundial]

to start debugging this, I'd print the values of xRotation and yRotation and see if they change when the camera jumps

if they don't, it may be something to do with the player parent, not the camera

[little hearth]

That's a good call

[vivid sundial]

if they do change, something is probably messing with the input axis

also, you should really use the new input system, it's way better!

again, something this tutorial doesn't cover, but it should

[little hearth]

Never show Wormy my code again

Joke aside, thanks for clarifying the thing about Find earlier @vivid sundial

[vivid sundial]

If you'd like me to show you some better ways to do what you're doing, I can, I suppose

[little hearth]

@vivid sundial One thing at a time lol. I'll figure it out eventually. Now i at least know about it.