gameobject in 2d array | Official Unity Discord | Page 1

modest crag Nov 8, 2021, 9:15 PM

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I have a 2d array which has a gameObject assigned to it but can't seem to access it in another script

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in one script I have this
public class Cell
{
public bool visited = false;
public GameObject north;
public GameObject east;
public GameObject south;
public GameObject west;
}

cells[rowCompare, colCompare].north = Instantiate(walls[0], new Vector3(rowCompare - 0.5f, 0, colCompare + 0.5f), Quaternion.identity);
"cells" is in the cell class which is how i've assigned a gameobject to the north wall

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in another script i have this:

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if (GameObject.Find("Generator").GetComponent<MazeGeneration>().cells[r, c].north != null)

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which is trying to find game objects that have a north wall with given "coordinates" but unity seems to think this doesnt exist

thorn dome Nov 8, 2021, 9:29 PM

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Well, if cells is in the Cell class, it of course wouldn't exist in the MazeGeneration class that you're getting from GetComponent?

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unless that was a typo :P

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You'd probably want to (properly) paste your MazeGeneration class too

modest crag Nov 8, 2021, 9:31 PM

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so MazeGeneration is my script that cells is created in

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📎 message.txt

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apologies for the comments making this chunkier than necessary

thorn dome Nov 8, 2021, 9:33 PM

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And what error do you get?

modest crag Nov 8, 2021, 9:34 PM

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i replaced if (GameObject.Find("Generator").GetComponent<MazeGeneration>().cells[r, c].north != null) with ```if (GameObject.Find("Generator").GetComponent<Cell>().cells[r, c].north != null)

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using UnityEngine;

public class MazeAlgorithm : MazeGeneration
{
    private int algRows;
    private int algColumns;
    private Cell[,] algCells;

    // Start is called before the first frame update
    void Start()
    {
        algRows = GameObject.Find("Generator").GetComponent<MazeGeneration>().rows;
        algColumns = GameObject.Find("Generator").GetComponent<MazeGeneration>().columns;
        Invoke("CopyCell", 2);
        StartAlgorithm();
    }

    private void CopyCell()
    {
        algCells = GameObject.Find("Generator").GetComponent<MazeGeneration>().cells;
    }

    private void StartAlgorithm()
    {
        for (int rowCompare = 0; rowCompare < algRows; rowCompare++)
        {
            for (int colCompare = 0; colCompare < algColumns; colCompare++)
            {
                AdjacencyCheck(rowCompare, colCompare);
            }
        }
    }

    private int AdjacencyCheck(int r, int c)
    {
        if (GameObject.Find("Generator").GetComponent<Cell>().cells[r, c].north != null)
        {
            Debug.Log(r);
            Debug.Log(c);
        }
        return (r);
    }

}

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here's the second script btw im just trying to access the gameobject

thorn dome Nov 8, 2021, 9:35 PM

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WEll yeah I just said that because you say the cells thing would be in Cell or so, but it isn't anyway

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What error does VS say exactly?

modest crag Nov 8, 2021, 9:36 PM

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thing is VS is okay with if (GameObject.Find("Generator").GetComponent<MazeGeneration>().cells[r, c].north != null)

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just unity isnt

thorn dome Nov 8, 2021, 9:36 PM

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also why does MazeAlgorithm inherit from MazeGeneration

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What does Unity say is the error then

modest crag Nov 8, 2021, 9:37 PM

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NullReferenceException: Object reference not set to an instance of an object
MazeAlgorithm.AdjacencyCheck (System.Int32 r, System.Int32 c) (at Assets/Scripts/MazeAlgorithm.cs:36)
MazeAlgorithm.StartAlgorithm () (at Assets/Scripts/MazeAlgorithm.cs:29)
MazeAlgorithm.Start () (at Assets/Scripts/MazeAlgorithm.cs:15)

thorn dome Nov 8, 2021, 9:38 PM

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for (int colCompare = 0; colCompare < rows; colCompare++) migth be your issue

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should be < columns surely?

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though you're breaking on that nayway

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but if rows is lower than cols..

modest crag Nov 8, 2021, 9:39 PM

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oh shit that was stupid of me

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never would have spotted that lol

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if (GameObject.Find("Generator").GetComponent<Cell>().cells[r, c].north != null)
has the VS error

Error    CS1061    'MazeGeneration.Cell' does not contain a definition for 'cells' and no accessible extension method 'cells' accepting a first argument of type 'MazeGeneration.Cell' could be found (are you missing a using directive or an assembly reference?)    Assembly-CSharp, Assembly-CSharp.Player    C:\Users\Tahseen Khan\Desktop\maze generation\Assets\Scripts\MazeAlgorithm.cs    36    Active

thorn dome Nov 8, 2021, 9:42 PM

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Yeah, you have to put <MazeGeneration> there, as said, I only said that thing because you stated cells would be in Cell

modest crag Nov 8, 2021, 9:43 PM

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thorn dome also why does MazeAlgorithm inherit from MazeGeneration

at first I made it inherit because i thought that would let me access the variables without using GameObject.Find but i was wrong lol

modest crag Nov 8, 2021, 9:43 PM

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thorn dome Yeah, you have to put <MazeGeneration> there, as said, I only said that thing be...

how would i correct this?

thorn dome Nov 8, 2021, 9:44 PM

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uh

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if (GameObject.Find("Generator").GetComponent<MazeGeneration>().cells[r, c].north != null)

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?

modest crag Nov 8, 2021, 9:44 PM

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getcomponent<mazegen>.getcomponent<cell> ?

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oh

modest crag Nov 8, 2021, 9:45 PM

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thorn dome `if (GameObject.Find("Generator").GetComponent<MazeGeneration>().cells[r, c].nor...

yeah how would i change this to specify that cells is in the class Cell

thorn dome Nov 8, 2021, 9:45 PM

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?

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It's not in the cells class

modest crag Nov 8, 2021, 9:45 PM

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cells = new Cell[rows, columns];

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tho

thorn dome Nov 8, 2021, 9:46 PM

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that just assigns the cells variable an array of Cell

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the cells variable is still in the MazeGeneration class though

modest crag Nov 8, 2021, 9:46 PM

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ahhh ok

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why does unity think (GameObject.Find("Generator").GetComponent<MazeGeneration>().cells[r, c].north doesn't exist

thorn dome Nov 8, 2021, 9:48 PM

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fixed that < columns thing?

modest crag Nov 8, 2021, 9:48 PM

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yep

thorn dome Nov 8, 2021, 9:52 PM

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The null error means that unity looks in the array at that location and finds a null, aka "no object". It's not that it doesn't find the variable.
But it finds null and then tries to access .north on that, so it errors.

Do you have MazeGeneration multiple times in your scene?

modest crag Nov 8, 2021, 9:52 PM

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just once

thorn dome Nov 8, 2021, 9:53 PM

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oh

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Try invoking the StartAlgorithm too

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so it runs a bit later

modest crag Nov 8, 2021, 9:54 PM

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i tried that but the code was dodgy at that point so ill retry ir

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holy shit it worked thanks a bunch

thorn dome Nov 8, 2021, 9:57 PM

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xD

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Yeah, the scripts don't run in a set order, so the array wasn't setup yet

modest crag Nov 8, 2021, 9:58 PM

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yeah i had thought of that before but the other holes in the code fucked it up lol

#gameobject in 2d array