Bug Tilemap.SetTIle() strange behaviour

Hello everyone! Recently I have encountered different behaviour of Tilemap.SetTile() in editor and android build. While debugging I have noticed that calling method Tilemap.SetTile() sets tile twice instead of single operation. I've noticed it by having prefab attached to on of the tiling rules of Isometric Rule tile. The component of prefab is clearly instantiated twice. It goes this way: Awake() call, OnDestroy() call, Awake() call - proving the point that tile is set twice in the same spot. I would've assumed that something wrong with my code if the behaviour was the same in editor. Has anybody encountered this?

 

Something in your logic is (most likely) calling it twice. You'll know when you're finished debugging because you will have solved the problem.

Time to start debugging! Here is how you can begin (or continue) your exciting new debugging adventures:

You must find a way to get the information you need in order to reason about what the problem is.

Once you understand what the problem is, you may begin to reason about a solution to the problem.

What is often happening in these cases is one of the following:

- the code you think is executing is not actually executing at all
- the code is executing far EARLIER or LATER than you think
- the code is executing far LESS OFTEN than you think
- the code is executing far MORE OFTEN than you think
- the code is executing on another GameObject than you think it is
- you're getting an error or warning and you haven't noticed it in the console window

To help gain more insight into your problem, I recommend liberally sprinkling

Debug.Log()

statements through your code to display information in realtime.

Doing this should help you answer these types of questions:

- is this code even running? which parts are running? how often does it run? what order does it run in?
- what are the names of the GameObjects or Components involved?
- what are the values of the variables involved? Are they initialized? Are the values reasonable?
- are you meeting ALL the requirements to receive callbacks such as triggers / colliders (review the documentation)

Knowing this information will help you reason about the behavior you are seeing.

You can also supply a second argument to Debug.Log() and when you click the message, it will highlight the object in scene, such as

Debug.Log("Problem!",this);

If your problem would benefit from in-scene or in-game visualization, Debug.DrawRay() or Debug.DrawLine() can help you visualize things like rays (used in raycasting) or distances.

You can also call Debug.Break() to pause the Editor when certain interesting pieces of code run, and then study the scene manually, looking for all the parts, where they are, what scripts are on them, etc.

You can also call GameObject.CreatePrimitive() to emplace debug-marker-ish objects in the scene at runtime.

You could also just display various important quantities in UI Text elements to watch them change as you play the game.

Visit Google for how to see console output from builds. If you are running a mobile device you can also view the console output. Google for how on your particular mobile target, such as this answer or iOS: https://forum.unity.com/threads/how-to-capturing-device-logs-on-ios.529920/ or this answer for Android: https://forum.unity.com/threads/how-to-capturing-device-logs-on-android.528680/

If you are working in VR, it might be useful to make your on onscreen log output, or integrate one from the asset store, so you can see what is happening as you operate your software.

Another useful approach is to temporarily strip out everything besides what is necessary to prove your issue. This can simplify and isolate compounding effects of other items in your scene or prefab.

Here's an example of putting in a laser-focused Debug.Log() and how that can save you a TON of time wallowing around speculating what might be going wrong:

https://forum.unity.com/threads/coroutine-missing-hint-and-error.1103197/#post-7100494

"When in doubt, print it out!(tm)" - Kurt Dekker (and many others)

Note: the

print()

function is an alias for Debug.Log() provided by the MonoBehaviour class.

 

Well, fortunately, posting a new thread on forum is not the first thing that I usually do. You can look at the difference in behaviour yourself.



That's exactly what I was talking about. The same action but different outcome in editor and apk. I'll check my theory in a brand new project with few lines of code without enormous hierarchy of scripts. And see whether behaviour is the same.

 

UPD:
I've just created a new project and wrote two scripts.
Script responsible for input and placement:

Code (CSharp):

1. public class PlacementSystem : MonoBehaviour
2. {
3.     [SerializeField]
4.     private Tilemap _tilemap;
5.     [SerializeField]
6.     private TileBase _treeTile;
7.     [SerializeField]
8.     private TileBase _grassTile;
9.  
10.     private void Update()
11.     {
12.         if (Input.GetMouseButtonDown(0))
13.         {
14.             Vector3 clickPosition = Camera.main.ScreenToWorldPoint(Input.mousePosition);
15.             clickPosition.z = 0;
16.  
17.             SetTile(_tilemap.WorldToCell(clickPosition), _treeTile);
18.         }
19.     }
20.  
21.     private void SetTile(Vector3Int tilemapPos, TileBase tile)
22.     {
23.         Debug.LogWarning("Setting tile");
24.         _tilemap.SetTile(tilemapPos, tile);
25.     }
26. }

Script "TileComponent" responsible for logging:

Code (CSharp):

1. public class TileComponent : MonoBehaviour
2. {
3.     private void Awake()
4.     {
5.         Debug.LogWarning($"Tile ({gameObject.name}) is instantiated");
6.     }
7.  
8.     private void OnDestroy()
9.     {
10.         Debug.LogWarning($"Tile ({gameObject.name}) is destroyed");
11.     }
12. }

Both grass and tree tiles have TileComponent.cs on gameobjects attached to the tiles. On Start we have tilemap painted with grass tile. My further action is to tap on any place on screen where a grass tile is. This leads to two different logs in editor and apk.



BTW, I have tested this in two versions of Unity:

• 2021.3.8f1;
• 2021.3.23f1;

Any thoughts? Or maybe I'm using Tilemap.SetTile() not the way it is intended. Anyway judging by logs, they shouldn't be different on target platform

 

Thank you for such a rapid response! I've sent a bug report - CASE IN-39311. Just in case you might want to look into the project setup itself.

 

Thank you very much for your help!

 

Awesome! I'm glad you've figured it out! Thank you very much for your work!