---
title: "Streamed Terrain World: API"
package: "@phaser-ae/terrain-world-3d"
tier: Free
version: 3.0.0-4
released: 2026-10-14
updated: 2026-10-20
description: "Streams a window of terrain tiles around the camera across landscapes too large for one height array, with fixed limits on memory, meshes and generation work."
url: https://phaser.io/packs/terrain-world-3d/api
site: Phaser - https://phaser.io
---

# Streamed Terrain World: API

`@phaser-ae/terrain-world-3d` — Camera-centred terrain tiles with bounded generation, mesh reuse, distance LOD and persistent sparse edits.

## The pack

### `terrainWorld3d`

```ts
function terrainWorld3d(options: TerrainWorld3dOptions = {}): Pack<{ terrainWorld: TerrainWorld3dApi }>
```

Recycles mesh and atlas slots while travelling; no world-sized height array is allocated.

## Classes

### `TerrainTileStore`

```ts
class TerrainTileStore
```

Sample storage stays bounded as travel proceeds. Only explicitly edited samples persist.

- `readonly tileSize: number` — World width and depth of one tile; default 192.
- `readonly resolution: number` — Quads along each tile side: 16, 32, 64, 128 or 256; default 64.
- `readonly cell: number` — World width of one sample cell: `tileSize / resolution`.
- `readonly amplitude: number` — Vertical scale of the built-in hills generator, in world units; default 160.
- `readonly cacheTiles: number` — Most source tiles kept in the least-recently-used cache, 1 to 1024; default 64.
- `constructor(options: TileStoreOptions = {})`
- `get residentTiles()` — Source tiles in the cache now, never more than `cacheTiles`.
- `get editedSamples()` — Authored height samples held, which survive cache eviction; at most 1,000,000.
- `heightAt: (x: number, z: number) => number` — Ground height at world (x, z), in world units, triangle-exact and without loading a tile. Throws for a coordinate that is not finite or lies beyond 1,000 km.
- `normalAt: (x: number, z: number) => { x: number; y: number; z: number; }` — Unit surface normal at world (x, z), from finite differences one cell either side; throws for a coordinate `heightAt` refuses.
- `tile(tx: number, tz: number): Heightfield` — The source heightfield for tile (`tx`, `tz`), counted in whole tiles; built on first use, then cached. Throws for non-integer indices or a tile beyond 1,000 km.
- `edit(edits: TerrainEdit[])` — Atomic offline edits. Shared edge samples are committed once, independent of tile order.
- `save()` — Persist with the same generator configuration; no procedural samples are stored.
- `load(document: ReturnType<TerrainTileStore['save']>)` — Replace the authored samples with a document from `save()`. Throws, leaving the store unchanged, if it is not version 1, was saved with another tile size or resolution, has more than 1,000,000 samples, or holds an invalid sample.

## Types

### `TerrainWorld3dApi`

```ts
interface TerrainWorld3dApi
```

Large-world terrain, sampled on a stable world-space lattice.

- `heightAt(x: number, z: number): number` — Triangle-exact ground height without allocating a tile.
- `normalAt(x: number, z: number): { x: number; y: number; z: number }` — Surface normal from neighbouring authoritative samples.
- `edit(edits: TerrainEdit[]): void` — Sculpt offline; authored samples survive tile eviction.
- `save(): ReturnType<TerrainTileStore['save']>` — Save sparse authored samples; restore with the same generator configuration.
- `load(document: ReturnType<TerrainTileStore['save']>): void` — Restore sparse authored samples and queue resident geometry for refresh.
- `readonly tiles: number` — Current rendered tile count, bounded by (2 * radius + 1) squared.
- `readonly cachedTiles: number` — Number of resident source heightfields in the bounded LRU cache.
- `readonly triangles: number` — Resident triangles before frustum culling.
- `readonly pending: number` — Tile builds waiting for the per-tick budget.

### `TerrainWorld3dOptions`

```ts
interface TerrainWorld3dOptions extends TileStoreOptions
```

Camera-centred terrain paging with explicit CPU, mesh and generation budgets.

- `radius?: number` — Tile radius around the camera, 1..6. Default 3 (49 resident mesh slots).
- `buildsPerTick?: number` — Maximum new tiles or LOD changes per simulation tick, 1..8. Default 2.

---

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