Physics2D.OverlapBox not working as expected.

Hello all. I’m trying to spawn game objects around a tilemap by checking if the object will not collide with anything before placing it. I essentially have a Decor object that contains the Required Size of the Object prefab it holds. For some reason though, Physics2D.OverlapBox() does not return a hit even if the box overlaps the walls, which have a TilemapCollider2D with a CompositeCollider2D. I’ve been searching for hours to find a solution, but nothing so far. I have the composite colllider’s Geometry Type set to Polygons, since the Outlines mode only creates EdgeColliders that are infinitely thin. I even tried Outline mode and setting the EdgeRadius to something ridiculous like 20 and still nothing. Any help is appreciated.


 public class Decor : ScriptableObject
        public Vector2Int RequiredSpace;
        [Range(0f, 1f)]
        public float Chance;
        public GameObject ObjectPrefab;

        public bool CanPlace(Vector3Int pos)
               var temp = new Vector2Int(pos.x, pos.y);
               return CanPlace(temp);
        public bool CanPlace(Vector2Int pos)

                var newPos = pos - ( / 2);
                var hit = Physics2D.OverlapBox(newPos, RequiredSpace, 0);
                Color color = (hit != null) ? Color.white :;

                Vector3 temp = new Vector3((float)newPos.x, (float)newPos.y, 0f);
                Debug.DrawLine(temp, temp + Vector3.up * RequiredSpace.x, color);
                Debug.DrawLine(temp, temp + Vector3.right * RequiredSpace.x, color);
                Debug.DrawLine(temp + Vector3.right * RequiredSpace.x, temp + (Vector3.up + Vector3.right) * RequiredSpace.x, color);
                Debug.DrawLine(temp + Vector3.up * RequiredSpace.x, temp + (Vector3.up + Vector3.right) * RequiredSpace.x, color);

                return hit == null;


And the following is the code I’m using to place the objects:

    foreach (var pos in floors.cellBounds.allPositionsWithin)
        if (floors.HasTile(pos))
            float roll = Random.Range(0, 1f);
            if (roll <= decorDensity)
                foreach (var possibleDecor in obstructiveDecorations)

                    roll = Random.Range(0f, 1f);

                    if (roll <= possibleDecor.Chance && possibleDecor.CanPlace(pos))
                        Instantiate(possibleDecor.ObjectPrefab, pos, Quaternion.identity);


When Testing for the writing of this post, I actually can’t tell what’s going on because it seems like it does sometimes return hits and sometimes it doesn’t. See the second image what I mean.

Firstly here is my Tilemap setup:

And here is a run. Successful placements are in green, failed ones are in white.


Welp apologies everyone. After doing some more digging and another look at the documentation, the point on the overlapbox function is the CENTER of the box. Here I was thinking that it was the bottom left corner, with the size essentially being the top right corner. Silly me! Hopefully someone will stumble across this later and save themselves the trouble. Or better yet just read the docs thoroughly!!