Unity 2D Tilemap

Author and script tile-based 2D levels in Unity 6 with the

Grid

Tilemap

system, the Tile Palette, colliders, and runtime painting. Targets Unity 6 (6000.0 LTS).

Package note: the core Tilemap (
Grid
,
Tilemap
,
Tile
,
TilemapCollider2D
) is built in. Rule Tiles, Animated Tiles, and Tile Palette brushes live in the separate "2D Tilemap Extras" package (
com.unity.2d.tilemap.extras
) — install it via Package Manager before using
RuleTile
.

When to use

Use when laying out a 2D level by painting tiles, setting up a
```
Grid
```
+
```
Tilemap
```
, adding collision to the map, using auto-tiling Rule Tiles, or generating/editing tiles from script.
Use when scenes contain a
```
Grid
```
with
```
Tilemap
```
children, or
```
*.asset
```
tile/palette files.

When not to use: level design practice (pacing, blockout, layout principles) →

level-design

. 3D tile/grid placement → Unity's own 3D tooling (ProBuilder / grid brushes; no dedicated skill here). The platformer character that moves over the tiles →

platformer

unity-physics

Core workflow

Create the grid: GameObject → 2D Object → Tilemap → Rectangular. This makes a
```
Grid
```
with a child
```
Tilemap
```
(+
```
TilemapRenderer
```
). Use one Tilemap per layer (background, ground, foreground) and set each renderer's sorting.
Open the Tile Palette (Window → 2D → Tile Palette), drag in a sliced sprite sheet to create
```
Tile
```
assets, then paint with the brush tools.
Add collision to the solid layer:
```
TilemapCollider2D
```
. For one merged collider (far cheaper and gap-free), also add
```
CompositeCollider2D
```
(+ a
```
Rigidbody2D
```
set to Static) and enable Used By Composite on the tilemap collider.
Auto-tile with Rule Tiles (2D Tilemap Extras) so edges/corners pick the right sprite automatically instead of hand-placing every variant.
Edit at runtime via script with cell coordinates (
```
Vector3Int
```
):
```
SetTile
```
,
```
GetTile
```
,
```
SetTilesBlock
```
, converting world↔cell with the
```
Grid
```
/
```
Tilemap
```
.
Verify in Play mode: confirm collisions (Physics Debugger), sorting order, and that
```
RefreshAllTiles
```
ran after bulk edits.

Patterns

1. Painting tiles at runtime (cell coordinates)

csharp

using UnityEngine;
using UnityEngine.Tilemaps;

public class TilePainter : MonoBehaviour
{
    [SerializeField] private Tilemap tilemap;   // assign the target Tilemap
    [SerializeField] private TileBase groundTile;

    // World position -> cell, then place a tile.
    public void PaintAt(Vector3 worldPos)
    {
        Vector3Int cell = tilemap.WorldToCell(worldPos);
        tilemap.SetTile(cell, groundTile);
    }

    public bool IsSolid(Vector3 worldPos)
        => tilemap.GetTile(tilemap.WorldToCell(worldPos)) != null;
}

2. Bulk fill a region (faster than per-cell

SetTile

)

csharp

// SetTilesBlock writes a whole BoundsInt in one call — use it for procedural rooms/floors.
public void FillFloor(Tilemap map, TileBase tile, int width, int height)
{
    var bounds = new BoundsInt(0, 0, 0, width, height, 1);
    var tiles  = new TileBase[width * height];
    for (int i = 0; i < tiles.Length; i++) tiles[i] = tile;
    map.SetTilesBlock(bounds, tiles);
}

3. Clearing and refreshing

csharp

tilemap.SetTile(cell, null);   // null erases the tile at that cell
tilemap.RefreshTile(cell);     // re-evaluate just this cell's rule/animated neighbors (cheap)
// RefreshAllTiles() re-evaluates the ENTIRE map — reserve it for full regenerations, not per-edit.

Pitfalls

RuleTile
type not found — it's not built in. Install the 2D Tilemap Extras package (
```
com.unity.2d.tilemap.extras
```
) via Package Manager.
A collider per tile tanks performance / leaves seams — add a
```
CompositeCollider2D
```
with a static
```
Rigidbody2D
```
and Used By Composite to merge the whole layer into one smooth shape.
Confusing world and cell coordinates —
```
SetTile
```
/
```
GetTile
```
take a
```
Vector3Int
```
cell, not a world position. Always convert with
```
WorldToCell
```
/
```
CellToWorld
```
.
Tiles render behind/in front of sprites unexpectedly — set each
```
TilemapRenderer
```
's Sorting Layer and Order in Layer; multiple tilemaps need explicit ordering.
Rule/animated tiles don't update after script edits — refresh after writes, but prefer the targeted
```
RefreshTile(cell)
```
for a few edits;
```
RefreshAllTiles()
```
re-evaluates every tile on the map and stalls large levels. Reserve the full refresh for whole-map regenerations.
Painting onto the wrong layer — the active target Tilemap in the Tile Palette determines where paint lands; check the "Active Tilemap" dropdown.

References

Primary docs: Unity Manual "Tilemaps" (

https://docs.unity3d.com/Manual/tilemaps/work-with-tilemaps/tilemap-reference.html

ScriptReference/Tilemaps.Tilemap

, and the 2D Tilemap Extras package manual (

https://docs.unity3d.com/Packages/com.unity.2d.tilemap.extras@1.6/manual/index.html

) for Rule Tiles.

Related skills

```
level-design
```
— engine-agnostic blockout, pacing, and tile layout practice.
```
procedural-gen
```
— generating the tile data (noise, RNG, dungeons) you feed to
```
SetTilesBlock
```
.
```
platformer
```
/
```
roguelike
```
— genres that compose this skill with movement and generation.

unity-tilemap-2d

NPX Install

Tags

SKILL.md Content

Unity 2D Tilemap

When to use

Core workflow

Patterns

1. Painting tiles at runtime (cell coordinates)

2. Bulk fill a region (faster than per-cell
`SetTile`
)

3. Clearing and refreshing

Pitfalls

References

Related skills

unity-tilemap-2d

NPX Install

Tags

SKILL.md Content

Unity 2D Tilemap

When to use

Core workflow

Patterns

1. Painting tiles at runtime (cell coordinates)

2. Bulk fill a region (faster than per-cell SetTile)

3. Clearing and refreshing

Pitfalls

References

Related skills

2. Bulk fill a region (faster than per-cell
`SetTile`
)