NullReferenceExceptions Error

Ok so I am getting the following error:

NullReferenceException: Object reference not set to an instance of an object.
LevelGenerator.placeElement (System.Int32 layer, System.String name, System.Int32 count, System.Single x, System.Single y, System.Single z, UnityEngine.GameObject objToPlace, UnityEngine.Vector3 scaleBy, UnityEngine.GameObject parent, System.Boolean doWeScale) (at Assets/Scripts/RabidGames/Generators/LevelGenerator.cs:567)
LevelGenerator.generateElement (System.Single x, System.Single z, System.String element, System.Single y) (at Assets/Scripts/RabidGames/Generators/LevelGenerator.cs:488)


For whatever reason it is not adding the GameObject to the mapCoords GameObject array. For whatever reason I can output the name like on line 565 but when line 566 runs I get the above error. If i comment out line 566 the program runs and instantiates the game objects and generates the level without issue. Here is the code below.:

 

The array "mapCoords" is null. Initialise the variable somewhere before using it e.g. in Start()

 

Yep - at no point do I see you assigning any value to any of the 4 arrays declared on lines 66-69.

 

I am trying to assign values on lines 566 for map coords, roadCoords on 575 is disabled because it was producing the same error. The other 2 arrays are meant to be filled after the level is generated for pathfinding purposes.

So are you saying I have to preload data into the arrays in start in order to add elements? Or are we doing it all wrong in general.

The idea is that the arrays mapCoords and roadCoords are to be filled as the level generates because we don't know the number of required elements at the onset of the level generation because the blocks can vary in count depending on the pixel map we use.

I get that I am apparently not understanding completely so if you guys could give me a little bit more direction it would be great.

Thanks

 

You need to assign a new array object to "mapCoords" before you can use it, otherwise you are trying to fill a nonexistent objects with values.

Somewhere in your code, before you try to populate mapCoords, you need to do something like:

mapCoords = new GameObject[height, width];

You can read more about multidimensional arrays here: https://docs.microsoft.com/en-us/dotnet/csharp/programming-guide/arrays/multidimensional-arrays

 

I was just trying to create a 2D array. I have put into Start()

Code (CSharp):

1. mapCoords = new GameObject[width, height];
2. roadCoords = new GameObject[width, height];

And it is still producing the same error. I am reading through the documentation you linked to. Should they be public instead of private static?

 

You made sure to do that before calling generateTerrain()? Post the whole Start() function.

 

Code (CSharp):

1. void Start()
2.     {
3.         mapCoords = new GameObject[width, height];
4.         roadCoords = new GameObject[width, height];
5.         treeCount = 0;
6.         roadCount = 0;
7.         castleCount = 0;
8.         clutterCount = 0;
9.         groundCount = 0;
10.         waterCount = 0;
11.         houseCount = 0;
12.         towerSpotCount = 0;
13.         blockCount = 0;
14.         waypointCounter = 0;
15.         generateTerrain();
16.     }

 

Post the entirety of the error message you are now getting with the full stack trace.

 

Code (CSharp):

1. NullReferenceException: Object reference not set to an instance of an object.
2. LevelGenerator.placeElement (System.Int32 layer, System.String name, System.Int32 count, System.Single x, System.Single y, System.Single z, UnityEngine.GameObject objToPlace, UnityEngine.Vector3 scaleBy, UnityEngine.GameObject parent, System.Boolean doWeScale) (at Assets/Scripts/RabidGames/Generators/LevelGenerator.cs:568)
3. LevelGenerator.generateElement (System.Single x, System.Single z, System.String element, System.Single y) (at Assets/Scripts/RabidGames/Generators/LevelGenerator.cs:490)
4. LevelGenerator.generateTerrain () (at Assets/Scripts/RabidGames/Generators/LevelGenerator.cs:431)
5. LevelGenerator.createTerrain () (at Assets/Scripts/RabidGames/Generators/LevelGenerator.cs:231)
6. System.Reflection.MonoMethod.Invoke (System.Object obj, System.Reflection.BindingFlags invokeAttr, System.Reflection.Binder binder, System.Object[] parameters, System.Globalization.CultureInfo culture) (at <fb001e01371b4adca20013e0ac763896>:0)
7. Rethrow as TargetInvocationException: Exception has been thrown by the target of an invocation.
8. System.Reflection.MonoMethod.Invoke (System.Object obj, System.Reflection.BindingFlags invokeAttr, System.Reflection.Binder binder, System.Object[] parameters, System.Globalization.CultureInfo culture) (at <fb001e01371b4adca20013e0ac763896>:0)
9. System.Reflection.MethodBase.Invoke (System.Object obj, System.Object[] parameters) (at <fb001e01371b4adca20013e0ac763896>:0)
10. Sirenix.OdinInspector.Editor.Drawers.DefaultMethodDrawer.InvokeButton () (at <5890bae5b1944292a9144c575f50aefa>:0)
11. UnityEngine.Debug:LogException(Exception)
12. Sirenix.OdinInspector.Editor.Drawers.DefaultMethodDrawer:InvokeButton()
13. Sirenix.OdinInspector.Editor.Drawers.DefaultMethodDrawer:DrawNormalButton()
14. Sirenix.OdinInspector.Editor.Drawers.DefaultMethodDrawer:DrawPropertyLayout(GUIContent)
15. Sirenix.OdinInspector.Editor.OdinDrawer:DrawProperty(GUIContent)
16. Sirenix.OdinInspector.Editor.InspectorProperty:Draw(GUIContent)
17. Sirenix.OdinInspector.Editor.InspectorUtilities:DrawPropertiesInTree(PropertyTree)
18. Sirenix.OdinInspector.Editor.PropertyTree:Draw(Boolean)
19. Sirenix.OdinInspector.Editor.OdinEditor:DrawTree()
20. Sirenix.OdinInspector.Editor.OdinEditor:DrawOdinInspector()
21. Sirenix.OdinInspector.Editor.OdinEditor:OnInspectorGUI()
22. UnityEngine.GUIUtility:processEvent(Int32, IntPtr)
23.  

 

I see.

It appears that Odin Inspector is invoking the "createTerrain" function before Start has even had a chance to run. Are you trying to create the terrain outside of play mode e.g. with an inspector button or something?

 

Thats exactly what I am trying to do

 

Well I am making progress I guess IDK why arrays and c# are so unfriendly but now I am getting IndexOutOfRange error

Code (CSharp):

1. IndexOutOfRangeException: Index was outside the bounds of the array.
2. LevelGenerator.placeElement (System.Int32 layer, System.String name, System.Int32 count, System.Single x, System.Single y, System.Single z, UnityEngine.GameObject objToPlace, UnityEngine.Vector3 scaleBy, UnityEngine.GameObject parent, System.Boolean doWeScale) (at Assets/Scripts/RabidGames/Generators/LevelGenerator.cs:571)
3. LevelGenerator.generateElement (System.Single x, System.Single z, System.String element, System.Single y) (at Assets/Scripts/RabidGames/Generators/LevelGenerator.cs:493)
4. LevelGenerator.generateTerrain () (at Assets/Scripts/RabidGames/Generators/LevelGenerator.cs:434)
5. LevelGenerator.createTerrain () (at Assets/Scripts/RabidGames/Generators/LevelGenerator.cs:231)
6. System.Reflection.MonoMethod.Invoke (System.Object obj, System.Reflection.BindingFlags invokeAttr, System.Reflection.Binder binder, System.Object[] parameters, System.Globalization.CultureInfo culture) (at <fb001e01371b4adca20013e0ac763896>:0)
7. Rethrow as TargetInvocationException: Exception has been thrown by the target of an invocation.
8. System.Reflection.MonoMethod.Invoke (System.Object obj, System.Reflection.BindingFlags invokeAttr, System.Reflection.Binder binder, System.Object[] parameters, System.Globalization.CultureInfo culture) (at <fb001e01371b4adca20013e0ac763896>:0)
9. System.Reflection.MethodBase.Invoke (System.Object obj, System.Object[] parameters) (at <fb001e01371b4adca20013e0ac763896>:0)
10. Sirenix.OdinInspector.Editor.Drawers.DefaultMethodDrawer.InvokeButton () (at <5890bae5b1944292a9144c575f50aefa>:0)
11. UnityEngine.Debug:LogException(Exception)
12. Sirenix.OdinInspector.Editor.Drawers.DefaultMethodDrawer:InvokeButton()
13. Sirenix.OdinInspector.Editor.Drawers.DefaultMethodDrawer:DrawNormalButton()
14. Sirenix.OdinInspector.Editor.Drawers.DefaultMethodDrawer:DrawPropertyLayout(GUIContent)
15. Sirenix.OdinInspector.Editor.OdinDrawer:DrawProperty(GUIContent)
16. Sirenix.OdinInspector.Editor.InspectorProperty:Draw(GUIContent)
17. Sirenix.OdinInspector.Editor.InspectorUtilities:DrawPropertiesInTree(PropertyTree)
18. Sirenix.OdinInspector.Editor.PropertyTree:Draw(Boolean)
19. Sirenix.OdinInspector.Editor.OdinEditor:DrawTree()
20. Sirenix.OdinInspector.Editor.OdinEditor:DrawOdinInspector()
21. Sirenix.OdinInspector.Editor.OdinEditor:OnInspectorGUI()
22. UnityEngine.GUIUtility:ProcessEvent(Int32, IntPtr)
23.  

Here is my code now with the updated changes

 

You are creating new arrays for mapCoords and roadCoords, but you are not setting them to the correct size. You create the arrays using the width/height variables

Code (CSharp):

1.         mapCoords = new GameObject[width, height];
2.  

But then use the "map" textures height/width when iterating to access the array.

Code (CSharp):

1.         for (int hcount = 0; hcount < map.height; hcount++)
2.  

These values are almost certainly not the same, and as such you try to access parts of the array that don't exist. You need to either ensure that width and height are the correct value before running (which might not work, as you seem to be using the width and height variables to pass the iterators current value to the placePath function, and not to store the actual height or width of anything), or set the size of the array based on what you are actually going to try and access:

Code (CSharp):

1. mapCoords = new GameObject[map.width, map.height];