Get the tile in unity tile map

Question

I am trying to get the sprite of a tile in unity from where a raycast hits. Right now it only works in some cases, and always in positive x.

This is my current code.

Vector3Int LocalPos = new Vector3Int((int)hit.point.x, (int)hit.point.y,0);

Sprite spr = tilemap.GetSprite(LocalPos);

From what I can tell it gets the correct sprite.

Edit: I removed pointless code

Answer 1

I guess you should read the manual, how Unity Tilemap is structured. If you create a Tilemap in Unity Editor, first you have a Grid and then a Tilemap under it. If you move Grid, Tilemap will move along it. This same thing is true for getting tiles in code. Tiles are stored in GridLayout space not in world space. So if you happen to start "drawing" you tiles from Scene world position 0,0,0 that doesn't mean Grid origin couldn't be in other location (like -2,-2,0 for example).

So one solution is to first convert screen mouse position to ray, then Raycast with this Ray against a plane matching Tilemap plane, then convert the world hit point to Grid space cell position and try to get a Tile.

It has been quite a while since I touched Tilemap and I'm no professional coder by any means, but this is one way to get your tiles under mouse cursor. I guess there might be more cleaner and shorter ways to do this...

if (Input.GetMouseButtonDown(0))
{
    // mouse position in screen space
    var mpos = Input.mousePosition;

    // Create a ray from camera to world
    var ray = Camera.main.ScreenPointToRay(mpos);

    // Create a Plane object to raycast against
    // Assume Tilemap resides on plane z 0
    var plane = new Plane(Vector3.back, Vector3.zero);

    // Do a Plane Raycast with your screen to world ray
    float hitDist;
    plane.Raycast(ray, out hitDist);

    // If you aimed towards this infinite Plane, it hit
    var point = ray.GetPoint(hitDist);
    Debug.Log("Point: " + point);

    // Convert hitpoint to Tilemap / GridLayout space
    // Cell position is an integer positions in GridLayout
    var tpos = tilemap.WorldToCell(point);

    // Try to get a tile from cell position
    var tile = tilemap.GetTile(tpos);

    if (tile != null)
    {
        // A tile exists in this cell
        Debug.Log("Tile sprite: " + tilemap.GetSprite(tpos));
    }
}

See also:

https://docs.unity3d.com/ScriptReference/Tilemaps.Tilemap.html

https://docs.unity3d.com/ScriptReference/GridLayout.html

https://docs.unity3d.com/ScriptReference/Plane.html