RayCast2D ignor hitting own Collider - unity3d

Question

Board.cs
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
public class Board : MonoBehaviour
{
public Transform m_emptySprite;
private int m_height = 14;
private int m_width = 6;
// number of rows where we won't have grid lines at the top
public int m_header = 8;
// Start is called before the first frame update
void Start()
{
DrawEmptyCells();
}
void DrawEmptyCells()
{
for (int y = 0; y < m_height - m_header; y++)
{
for (int x = 0; x < m_width; x++)
{
Transform tile;
tile = Instantiate(m_emptySprite, new Vector3(x, y, 0), Quaternion.identity) as Transform;
tile.name = "Tile ( x = " + x.ToString() + " ,y = " + y.ToString() + ")";
tile.transform.parent = transform;
}
}
}
}
Tile.cs
public class Tile : MonoBehaviour
{
private Vector2[] adjacentDirections = new Vector2[] { Vector2.up, Vector2.down, Vector2.left, Vector2.right };
void OnMouseDown()
{
GetAllAdjacentTiles();
}
private GameObject GetAdjacent(Vector2 castDir)
{
RaycastHit2D hit = Physics2D.Raycast(transform.position, castDir);
if (hit.collider != null)
{
print(hit.collider.gameObject.name);
return hit.collider.gameObject;
}
return null;
}
private List<GameObject> GetAllAdjacentTiles()
{
List<GameObject> adjacentTiles = new List<GameObject>();
for (int i = 0; i < adjacentDirections.Length; i++)
{
adjacentTiles.Add(GetAdjacent(adjacentDirections[i]));
}
return adjacentTiles;
}
}
I have tried to use the code above to detect tiles in all 4 directions but when I click on a tile I just get the name of the tile that was clicked.
Each tile has the Tile Script and a BoxCollider2D attached, why is it not printing all 4 tiles surrounding the current tile?

Answer 1

By default for Physics2D you are hitting your own collider the Raycast starts in.
To solve this go to the Physics2D Settings via Edit → Project Settings → Physics2D and disable the option
Queries Start In Colliders
Enable this option if you want physics queries that start inside a Collider 2D to detect the collider they start in.