bevy/release-content/release-notes/tilemap-chunk-rendering.md
Conner Petzold 3f187cf752
Add TilemapChunk rendering (#18866)
# Objective

An attempt to start building a base for first-party tilemaps (#13782).

The objective is to create a very simple tilemap chunk rendering plugin
that can be used as a building block for 3rd-party tilemap crates, and
eventually a first-party tilemap implementation.

## Solution

- Introduces two user-facing components, `TilemapChunk` and
`TilemapChunkIndices`, and a new material `TilemapChunkMaterial`.
- `TilemapChunk` holds the chunk and tile sizes, and the tileset image
- The tileset image is expected to be a layered image for use with
`texture_2d_array`, with the assumption that atlases or multiple images
would go through an asset loader/processor. Not sure if that should be
part of this PR or not..
- `TilemapChunkIndices` holds a 1d representation of all of the tile's
Option<u32> index into the tileset image.
- Indices are fixed to the size of tiles in a chunk (though maybe this
should just be an assertion instead?)
  - Indices are cloned and sent to the shader through a u32 texture.

## Testing

- Initial testing done with the `tilemap_chunk` example, though I need
to include some way to update indices as part of it.
- Tested wasm with webgl2 and webgpu
- I'm thinking it would probably be good to do some basic perf testing.

---

## Showcase

```rust
let chunk_size = UVec2::splat(64);
let tile_size = UVec2::splat(16);
let indices: Vec<Option<u32>> = (0..chunk_size.x * chunk_size.y)
    .map(|_| rng.gen_range(0..5))
    .map(|i| if i == 0 { None } else { Some(i - 1) })
    .collect();

commands.spawn((
    TilemapChunk {
        chunk_size,
        tile_size,
        tileset,
    },
    TilemapChunkIndices(indices),
));
```

![Screenshot 2025-04-17 at 11 54
56 PM](https://github.com/user-attachments/assets/850a53c1-16fc-405d-aad2-8ef5a0060fea)
2025-06-23 23:55:10 +00:00

779 B

title authors pull_requests
Tilemap Chunk Rendering
@ConnerPetzold
@grind086
@IceSentry
18866

A performant way to render tilemap chunks has been added as the first building block to Bevy's tilemap support. You can render a chunk by supplying a tileset texture to the TilemapChunk component and the indices into that tileset for each tile to TilemapChunkIndices.

let chunk_size = UVec2::splat(64);
let tile_size = UVec2::splat(16);
let indices: Vec<Option<u32>> = (0..chunk_size.x * chunk_size.y)
    .map(|_| rng.gen_range(0..5))
    .map(|i| if i == 0 { None } else { Some(i - 1) })
    .collect();

commands.spawn((
    TilemapChunk {
        chunk_size,
        tile_size,
        tileset,
    },
    TilemapChunkIndices(indices),
));