Tilemap painting in Unity - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

What is the output of this Tilemap painting code?

Consider this Unity C# script snippet that paints tiles on a Tilemap. What will be the color of the tile at position (1, 1) after running this code?

Unity

using UnityEngine;
using UnityEngine.Tilemaps;

public class PaintTiles : MonoBehaviour {
    public Tilemap tilemap;
    public TileBase tile;

    void Start() {
        Vector3Int pos = new Vector3Int(1, 1, 0);
        tilemap.SetTile(pos, tile);
        tilemap.SetColor(pos, Color.red);
        tilemap.SetColor(new Vector3Int(0, 0, 0), Color.blue);
    }
}

A The tile at (1,1) is transparent (no color).

B The tile at (1,1) is red.

C The tile at (1,1) has the default color (white).

D The tile at (1,1) is blue.

💡 Hint

Remember that SetColor changes the color of the tile at the specified position.

The code sets the tile at (1,1) and then colors it red. The blue color is applied to a different tile at (0,0), so (1,1) remains red.

🧠 Conceptual

intermediate

Which method paints a tile on a Tilemap in Unity?

In Unity's Tilemap system, which method is used to place a tile at a specific grid position?

A tilemap.SetTile(Vector3Int position, TileBase tile)

B tilemap.PlaceTile(Vector3Int position, TileBase tile)

C tilemap.AddTile(Vector3Int position, TileBase tile)

D tilemap.PaintTile(Vector3Int position, TileBase tile)

💡 Hint

Look for the official Unity Tilemap API method that sets a tile.

The correct method to place a tile on a Tilemap is SetTile. Other methods do not exist in the API.

🔧 Debug

advanced

Why does this Tilemap painting code not show the tile?

Look at this code snippet. Why does the tile not appear on the Tilemap after running?

Unity

using UnityEngine;
using UnityEngine.Tilemaps;

public class PaintTiles : MonoBehaviour {
    public Tilemap tilemap;
    public TileBase tile;

    void Start() {
        Vector3 pos = new Vector3(2, 2, 0);
        tilemap.SetTile(Vector3Int.FloorToInt(pos), tile);
    }
}

A Vector3Int.FloorToInt(pos) is invalid and causes a runtime error.

B Using Vector3 instead of Vector3Int causes the tile not to appear.

C The tile variable is not assigned, so no tile is painted.

D Tilemap.SetTile requires a Vector3 position, not Vector3Int.

💡 Hint

Check if the tile variable has a value before painting.

If the tile variable is null (not assigned in the inspector), SetTile will not paint anything visible.

📝 Syntax

advanced

Which option correctly paints multiple tiles in a loop?

Which code snippet correctly paints tiles at positions (0,0), (1,0), and (2,0) on a Tilemap?

A for (int x = 0; x < 3; x++) { tilemap.SetTile(new Vector3Int(x, 0, 0), tile); }

B for (int x = 0; x < 3; x++) { tilemap.SetTile(new Vector3(x, 0, 0), tile); }

C for (int x = 0; x < 3; x++) { tilemap.SetTile(new Vector2Int(x, 0), tile); }

D for (int x = 0; x < 3; x++) { tilemap.SetTile(new Vector2(x, 0), tile); }

💡 Hint

Tilemap.SetTile requires a Vector3Int position.

SetTile expects a Vector3Int for the position. Option A uses Vector3Int correctly. Option A uses Vector3 which is invalid. Options C and D use Vector2Int and Vector2 which are not accepted.

🚀 Application

expert

How many tiles are painted after this code runs?

Given this code, how many tiles will be painted on the Tilemap?

Unity

using UnityEngine;
using UnityEngine.Tilemaps;

public class PaintTiles : MonoBehaviour {
    public Tilemap tilemap;
    public TileBase tile;

    void Start() {
        for (int x = 0; x < 3; x++) {
            for (int y = 0; y < 3; y++) {
                if ((x + y) % 2 == 0) {
                    tilemap.SetTile(new Vector3Int(x, y, 0), tile);
                }
            }
        }
    }
}

A 9 tiles

B 6 tiles

C 4 tiles

D 5 tiles

💡 Hint

Count how many (x,y) pairs from 0 to 2 satisfy (x + y) % 2 == 0.

The pairs where (x + y) is even are: (0,0), (0,2), (1,1), (2,0), (2,2). That's 5 tiles painted.