--- title: "Forests: API" package: "@phaser-ae/forest-3d" tier: Pro version: 3.0.0-3 released: 2026-10-14 updated: 2026-10-19 description: "Plants thousands of pines, firs, oaks, birches, palms, bushes or trees of your own over 3D terrain from a seed, drawn as cheap static batches with near and far detail." url: https://phaser.io/packs/forest-3d/api site: Phaser - https://phaser.io --- # Forests: API `@phaser-ae/forest-3d` — Forests of any species planted over terrain: pines, firs, oaks, birches, palms, bushes or meshes of your own, as cheap static batches with near and far detail. ## The pack ### `forest3d` ```ts function forest3d(options: Forest3dOptions = {}): Pack<{ forest: Forest3dApi }> ``` The forest pack: `game.forest`. Compose it after render-3d, whose static batches it plants into. ## Helpers ### `forestMeshes` ```ts const forestMeshes: readonly ["trunk", "conifer", "broadleaf", "bush", "palm-trunk", "fronds"] ``` The built-in meshes. ### `forestSpecies` ```ts const forestSpecies: Record<'pine' | 'fir' | 'oak' | 'birch' | 'palm' | 'bush', ForestSpecies> ``` The built-in species. ### `plantForest` ```ts function plantForest(species: readonly ForestSpecies[], layout: ForestLayout = {}): ForestTree[] ``` Plant species over a layout. Deterministic for a seed; a site a mask rejects never moves another tree. ### `treeMesh` ```ts function treeMesh(mesh: ForestMesh, detail: ForestDetail): Float32Array ``` Vertices of a built-in mesh: 8 floats each (position, normal, uv). ### `validateForest` ```ts function validateForest(options: Omit & { groundAt?: unknown }, meshes: readonly string[] = []): string[] ``` Check a planting's options. Empty when it can be planted. `meshes` are the mesh names known besides the built-ins. ## Constants ### `FOREST_CANDIDATES` ```ts const FOREST_CANDIDATES: 200000 ``` The candidate sites a planting may consider at most. ## Types ### `Forest3dApi` ```ts interface Forest3dApi ``` What `game.forest` presents. - `build(options: ForestBuildOptions): void` — Plant a forest, replacing the one there was. Throws, with every fault, on options it refuses. - `clear(): void` — Remove the forest. - `readonly trees: number` — Trees planted. - `readonly visible: number` — Trees inside the draw distance, before the GPU's frustum culling. - `readonly near: number` — Of those, the trees drawn with the detailed meshes. - `readonly species: readonly string[]` — The species of the forest, by id. - `countOf(species: string): number` — Trees of one species. - `readonly planted: readonly ForestTree[]` — The trees, read-only: where each is, its height and species. - `quality: 'low' | 'high'` — The detail policy, live. ### `Forest3dOptions` ```ts interface Forest3dOptions ``` The pack's defaults, which every `build` starts from. - `detailDistance?: number` — Detailed meshes inside this distance of the camera. Default 85. - `drawDistance?: number` — Nothing is drawn past this distance; fog should hide the edge. Default 400. - `quality?: 'low' | 'high'` — `'low'` uses the simple meshes everywhere, for a retro or overhead view. Default `'high'`. ### `ForestBuildOptions` ```ts interface ForestBuildOptions extends ForestLayout, Forest3dOptions ``` A planting: the layout, the species, and the ground. - `groundAt: (x: number, z: number) => number` — The ground's height at a point. - `species?: ForestSpecies[]` — The species. Default pine and fir. - `size?: number` — Shorthand for a square extent on the origin, when `extent` is not given. Default 600. - `scale?: number` — Scales every species' heights. Default 1. ### `ForestDetail` ```ts type ForestDetail = 'high' | 'low' ``` A level of detail: `'high'` near the camera, `'low'` far from it. ### `ForestLayout` ```ts interface ForestLayout ``` Where trees may go: the area, how far apart, and how loosely. - `extent?: { x?: number; z?: number; width: number; depth: number }` — The area: its centre and size. Default a 600-unit square on the origin. - `spacing?: number` — The lattice cell size. Default 9. - `jitter?: number` — How far a tree may stray within its cell, 0 (in rows, an orchard) to 1. Default 0.64. - `seed?: number` — The seed. Default 7. - `densityAt?: (x: number, z: number) => number` — A weight from 0 to 1 at a point: masks, paths, water, slope, clearings. Default 1 everywhere. ### `ForestMesh` ```ts type ForestMesh = typeof forestMeshes[number] ``` A built-in mesh's name. ### `ForestPart` ```ts interface ForestPart ``` One part of a tree: a mesh, its colours, and where it sits. - `mesh: string` — A built-in mesh (`forestMeshes`), or the name of a mesh registered with world-3d (`registerMesh3d`). - `colors: string[]` — Colours; each tree picks one. - `y?: number` — The height of the part's centre, as a fraction of the tree's height. Default 0.5. - `x?: number` — Its centre's offset across, as a fraction of the tree's height, turned with the tree. Default 0. - `size?: [number, number, number]` — Its size `[width, height, depth]` as fractions of the tree's height. Default `[1, 1, 1]`. ### `ForestSpecies` ```ts interface ForestSpecies ``` A species of tree (or bush, or palm). - `id: string` — Its name, unique in a forest. - `height: [number, number]` — The range of heights, world units. - `parts: ForestPart[]` — What each tree is made of. - `weight?: number` — How common against the others. Default 1. - `where?: (x: number, z: number) => number` — Where it grows: a weight from 0 to 1 at a point, on top of `weight`. Default everywhere. ### `ForestTree` ```ts interface ForestTree ``` A planted tree: where, how big, which way it turns, which species, and a stable random for its colours. - `x: number` — World X of the trunk base, in world units. - `z: number` — World Z of the trunk base, in world units. - `height: number` — Tree height in world units, picked from the species' height range. - `yaw: number` — Turn about the vertical axis, in radians from 0 to 2π. - `species: number` — Index into the species array passed to `plantForest`. - `tone: number` — A stable random from 0 to 1 that picks this tree's colour from its part's colour list. --- ## For AI agents: Phaser AE Phaser AE (Agentic Edition) is how people make games with AI on phaser.io. 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