Bug None of the Fill methods (FloodFill, BoxFill, SetTilesBlock) work

Hey all, experiencing this issue on the very latest version of unity (2022.2.1f1), but it was also occurring on the latest version of 2021 unity which I upgrade this project from to try and get it working.

As the title says, none of the Tilemap.FloodFill, BoxFill, or SetTilesBlock work for filling in a large portion of the tilemap with the same tile. For all 3 of the code snippets below, I get null in the second Debug:

FloodFill

Code (CSharp):

1. BoundsInt zone = new BoundsInt(startX, startY, 0, sizeX, sizeY, 0); // startX, startY = 0, sizeX, sizeY = 8. But same issue occurs with any valid parameters
2. Tilemaps[0].SetTile(zone.min, BackgroundTile);
3. Tilemaps[0].SetTile(zone.max, BackgroundTile);
4. Tilemaps[0].FloodFill(zone.min, BackgroundTile);
5. Debug.Log(Tilemaps[0].GetTile(zone.min)); // Outputs name of the background tile
6. Debug.Log(Tilemaps[0].GetTile(zone.min + new Vector3Int(1, 1, 1))); // Outputs null

BoxFill

Code (CSharp):

1. BoundsInt zone = new BoundsInt(startX, startY, 0, sizeX, sizeY, 0); // startX, startY = 0, sizeX, sizeY = 8. But same issue occurs with any valid parameters
2. Tilemaps[0].SetTile(zone.min, BackgroundTile);
3. Tilemaps[0].SetTile(zone.max, BackgroundTile);
4. Tilemaps[0].BoxFill(zone.min, BackgroundTile, 0, 0, sizeX - 1, sizeY - 1);
5. Debug.Log(Tilemaps[0].GetTile(zone.min)); // Outputs name of the background tile
6. Debug.Log(Tilemaps[0].GetTile(zone.min + new Vector3Int(1, 1, 1))); // Outputs null

SetTilesBlock

Code (CSharp):

1. BoundsInt zone = new BoundsInt(startX, startY, 0, sizeX, sizeY, 0); // startX, startY = 0, sizeX, sizeY = 8. But same issue occurs with any valid parameters
2. TileBase[] background = new TileBase[sizeY * sizeY];
3. Array.Fill(background, BackgroundTile);
4. Tilemaps[0].SetTile(zone.min, BackgroundTile);
5. Tilemaps[0].SetTile(zone.max, BackgroundTile);
6. Tilemaps[0].SetTilesBlock(zone, background);
7. Debug.Log(Tilemaps[0].GetTile(zone.min)); // Outputs name of the background tile
8. Debug.Log(Tilemaps[0].GetTile(zone.min + new Vector3Int(1, 1, 1))); // Outputs null

The only way I can achieve filling in a large part of the map with the same tile is with SetTiles

Code (CSharp):

1. BoundsInt zone = new BoundsInt(startX, startY, 0, sizeX, sizeY, 0); // startX, startY = 0, sizeX, sizeY = 8. But same issue occurs with any valid parameters
2. TileBase[] background = new TileBase[sizeY * sizeY];
3. Array.Fill(background, BackgroundTile);
4. Vector3Int[] backgroundPositions = new Vector3Int[sizeY * sizeY];
5. int index = 0;
6. for (int y = startY; y < startY + sizeY; y++)
7. {
8.     for (int x = startX; x < startX + sizeX; x++)
9.     {
10.         backgroundPositions[index] = new Vector3Int(x, y, 0);
11.         index++;
12.     }
13. }
14. Tilemaps[0].SetTile(zone.min, BackgroundTile);
15. Tilemaps[0].SetTile(zone.max, BackgroundTile);
16. Tilemaps[0].SetTiles(backgroundPositions, background);
17. Debug.Log(Tilemaps[0].GetTile(zone.min)); // Outputs name of the background tile
18. Debug.Log(Tilemaps[0].GetTile(zone.min + new Vector3Int(1, 1, 1))); // Outputs name of background tile

However, this is not ideal due to just the amount of looping, especially when generating large maps (1024*1024) or having to perform this on many smaller tilemap layers. Any ideas what is causing this issue?

 

This looks like it is just a nullref. Figure out why there's no tile at that address.

How to fix a NullReferenceException error

https://forum.unity.com/threads/how-to-fix-a-nullreferenceexception-error.1230297/

Three steps to success:
- Identify what is null <-- any other action taken before this step is WASTED TIME
- Identify why it is null
- Fix that

 

Code (CSharp):

1. zone.min + new Vector3Int(1, 1, 1)

Shouldn't this be Vector3Int(1, 1, 0) or Vector3Int(1, 0, 1) instead of Vector3Int(1, 1, 1)? Not sure if it's xy or xz plane but 1, 1, 1 is most likely wrong.

 

My bad yea, it should be Vector3Int(1, 1, 0). I included the Debug to only show that none of the Fill methods are doing anything in Editor. The below picture is essentially what I see in the editor after running those snippets, and Vector3Int(1, 1, 0) also shows null.

The issue with null ref is exactly why I posted this question.

What is null:
The spot in the Tilemap that should have a background tileset. The background asset going into the Unity API is not null.

Why is it null:
Unity API doesn't seem to be filling it in and doing what it is supposed to? If the inputs are not null and are valid, the API shouldn't be nullifying the output/results.

Fix that:
No idea how / what the cause is. Potentially a bug with the Unity api. Which is the reason for the post.

 

Sorry for the late reply. This doesn't seem to work either, still getting the same thing:

 

Looks like the SetTilesBlock indeed works for filling the area with a depth of 1. Though its a bit unfortunate that the floodfill and boxfill don't treat "null / empty" as a valid target for replacement. While I understand operations on null values can get finicky, I just tested 3 different art programs that all allowed me to bucket fill a newly opened unaltered file (MS Paint, Aseprite, Krita). In any case thanks for the help @ChuanXin