Question How to Highlight a Tile on Click (Troubleshooting SetTile)

Hi,

I followed a tutorial to try to get one of my tiles to highlight on click (or mouseover), but it doesn't seem to be working. This is my first time seeking help with Unity, so please bear with me.

In my scene I have a grid with two tilemaps as children: Interactive and Terrain. My intent is for Interactive to show the highlight using a HighlightTile sprite, while Terrain shows the default sprite.

The grid has the following script attached to it:

Code (CSharp):

1. using System.Collections;
2. using System.Collections.Generic;
3. using UnityEngine;
4. using UnityEngine.Tilemaps;
5. using UnityEngine.UIElements;
6.  
7.  
8. public class GridController : MonoBehaviour {
9.  
10.     private Grid grid;
11.  
12.     [SerializeField] private Tilemap interactiveMap = null;
13.     [SerializeField] private TileBase hoverTile = null;
14.  
15.     private Vector3Int previousMousePos = new Vector3Int();
16.  
17.     void Start() {
18.         grid = gameObject.GetComponent<Grid>();
19.     }
20.  
21.     void Update()
22.     {
23.  
24.         Vector3Int mousePos = GetMousePosition();
25.  
26.         if (!mousePos.Equals(previousMousePos)) {
27.             interactiveMap.SetTile(previousMousePos, null); // Remove old hoverTile
28.             interactiveMap.SetTile(mousePos, hoverTile);
29.             previousMousePos = mousePos;
30.         }
31.  
32.         if (Input.GetMouseButton(0))  {
33.             interactiveMap.SetTile(mousePos, hoverTile);
34.         }
35.  
36.         if (Input.GetMouseButton(1)) {
37.             interactiveMap.SetTile(mousePos, null);
38.         }
39.  
40.     }
41.  
42.     Vector3Int GetMousePosition() {
43.         Vector3 mouseWorldPos = Camera.main.ScreenToWorldPoint(Input.mousePosition);
44.         return grid.WorldToCell(mouseWorldPos);
45.     }
46.  
47. }

The code is currently redundant (using both mouse position and click) as I'm still just trying to get something to work. Also, I had to change the hoverTile type from Tile to TileBase, as I got a type conversion error when using SetTile.

And for reference, here's what my setup looks like:



Right now, if I run the game, no matter whether I hover over the tiles or click on them, it does nothing. Any help or suggestions is appreciated. Also, let me know what other information might be needed to solve this problem.

Thanks in advance.

 

the mouse position isn't the same as the tilemap 'grid' position. the mouse position is in screen coordinates.
Here's an example of how to do it from my own code

Code (CSharp):

1. using TilePlus;
2. using UnityEngine;
3. using UnityEngine.Tilemaps;
4.  
5. namespace TilePlusDemo
6. {
7.     /// <summary>
8.     /// An example of how to control a tile from a mouse-click.
9.     /// </summary>
10.     public class TpPickTile : MonoBehaviour
11.     {
12.         /// <summary>
13.         ///The tilemap
14.         /// </summary>
15.         [Tooltip("The tilemap")]
16.         public Tilemap m_Tilemap;
17.  
18.         /// <summary>
19.         /// The camera
20.         /// </summary>
21.         [Tooltip("The camera")]
22.         public Camera m_Camera;
23.  
24.         /// <summary>
25.         /// Delay between moves used for debouncing
26.         /// </summary>
27.         [Tooltip("Delay between moves for debouncing, min=0.2")]
28.         public float m_Delay = 0.2f;
29.  
30.         //used for debouncing
31.         private float lastTime;
32.  
33.         //used for debouncing
34.         private float timeAccum;
35.  
36.         private void Update()
37.         {
38.             // +debounce
39.             timeAccum += Time.deltaTime;
40.  
41.             if (!Input.GetMouseButton(0))
42.                 return;
43.  
44.             if (m_Delay < 0.2f)
45.                 m_Delay = 0.2f;
46.             if (timeAccum < (lastTime + m_Delay))
47.                 return;
48.             lastTime = timeAccum;
49.  
50.             // -debounce
51.            
52.            
53.             //get the mouse position
54.             var screenPos = Input.mousePosition;
55.             //test to ensure that it's within the visible area
56.             if (screenPos.x < 0 ||
57.                 screenPos.y < 0 ||
58.                 screenPos.x > Screen.width ||
59.                 screenPos.y > Screen.height)
60.                 return;
61.            
62.             //get the tilemap grid position
63.             var worldPos = m_Camera.ScreenToWorldPoint(screenPos);
64.             var gridPos = m_Tilemap.WorldToCell(worldPos);
65.            
66.             /*
67.             Your code goes here - gridpos is the tile coordinate
68.  
69.             */
70.  
71.         }
72.     }
73. }
74.  

Hope this helps.

 

Thanks. This worked, although for some reason I had to add +10 to the Z coordinate of each grid position. Any ideas as to why this was needed? Not really necessary to know, but it'd be helpful for future reference.

Here's my (now working) code:

Spoiler

Code (CSharp):

1. using UnityEngine;
2. using UnityEngine.Tilemaps;
3.  
4. public class GridController : MonoBehaviour {
5.  
6.     [SerializeField] private Tilemap m_Tilemap = null;
7.     [SerializeField] private Camera m_Camera = null;
8.     [SerializeField] private TileBase selectedTile = null;
9.  
10.     private Vector3Int previousGridPos = new Vector3Int();
11.  
12.     /// <summary>
13.     /// Delay between moves used for debouncing
14.     /// </summary>
15.     public float m_Delay = 0.2f;
16.  
17.     //used for debouncing
18.     private float lastTime;
19.  
20.     //used for debouncing
21.     private float timeAccum;
22.  
23.     void Update()
24.     {
25.  
26.         // +debounce
27.         timeAccum += Time.deltaTime;
28.  
29.         if (!Input.GetMouseButton(0))
30.             return;
31.  
32.         if (m_Delay < 0.2f)
33.             m_Delay = 0.2f;
34.         if (timeAccum < (lastTime + m_Delay))
35.             return;
36.         lastTime = timeAccum;
37.  
38.         // -debounce
39.  
40.         //get the mouse position
41.         var screenPos = Input.mousePosition;
42.         //test to ensure that it's within the visible area
43.         if (screenPos.x < 0 ||
44.             screenPos.y < 0 ||
45.             screenPos.x > Screen.width ||
46.             screenPos.y > Screen.height) {
47.             return;
48.         }
49.  
50.         var worldPos = m_Camera.ScreenToWorldPoint(screenPos);
51.         var gridPos = m_Tilemap.WorldToCell(worldPos);
52.  
53.         //test to ensure that it's within the visible area
54.         if (screenPos.x < 0 ||
55.             screenPos.y < 0 ||
56.             screenPos.x > Screen.width ||
57.             screenPos.y > Screen.height)
58.             return;
59.  
60.         if (!gridPos.Equals(previousGridPos))
61.         {
62.             var adjPos = gridPos + new Vector3Int(0, 0, 10);
63.             var adjPrev = previousGridPos + new Vector3Int(0, 0, 10);
64.             Debug.Log("gridPos: " + adjPos);
65.             Debug.Log("previousGridPos: " + adjPrev);
66.             m_Tilemap.SetTile(adjPrev, null); // Remove old tile
67.             m_Tilemap.SetTile(adjPos, selectedTile);
68.             previousGridPos = gridPos;
69.         }
70.     }
71. }
72.  

 

One thing - you don't need this twice, although it shouldn't hurt anything

      //test to ensure that it's within the visible area

        if (screenPos.x < 0 ||

            screenPos.y < 0 ||

            screenPos.x > Screen.width ||

            screenPos.y > Screen.height)

            return;

the only reason I can think of for requiring the offset is that you're using a custom orientation or Tile Anchor. If a normal XY tilemap's Z position is 0 and there's no custom orientation or tile anchor then the Z parameter should be zero.

 

I should have thought of that one... the way I'm using it the Z doesn't matter (not using Tilemap.GetTile). My bad :-(