---
title: "Ambient Occlusion: API"
package: "@phaser-ae/ssao-3d"
tier: Free
version: 3.0.0-3
released: 2026-10-14
updated: 2026-10-19
description: "Screen-space ambient occlusion that darkens creases and contacts, so 3D objects sit against one another and the ground instead of floating in the same room."
url: https://phaser.io/packs/ssao-3d/api
site: Phaser - https://phaser.io
---

# Ambient Occlusion: API

`@phaser-ae/ssao-3d` — Half-resolution screen-space occlusion, bilaterally blurred and multiplied into the scene.

## The pack

### `ssao3d`

```ts
function ssao3d(opts: Ssao3dOptions = {}): Pack<{ ssao: Ssao3dApi }>
```

The `ssao-3d` pack: half-resolution ambient occlusion, bilaterally blurred and multiplied into the scene.
Requires a 3D world and `render-3d`, whose depth it reads and whose camera it shares.

## Functions

### `buildSsaoBlurWGSL`

```ts
function buildSsaoBlurWGSL(): string
```

A BILATERAL five-tap cross blur, one horizontal and vertical pass at half resolution. The taps are weighted
by depth similarity, using the linear depth the estimate wrote into green, so occlusion never bleeds across
a silhouette — a plain blur draws a HALO around every object.

### `buildSsaoCompositeWGSL`

```ts
function buildSsaoCompositeWGSL(): string
```

The composite: a full-screen multiply-darken. The fragment writes the occlusion as a grey and the pipeline
blends zero-by-source, so the scene is multiplied by it. The linear sampler does the half-to-full upscale
for free, which smooths the result a little further at no cost.

### `buildSsaoWGSL`

```ts
function buildSsaoWGSL(): string
```

The AO estimate, at half resolution.

### `ssaoKernel`

```ts
function ssaoKernel(n: number = SAMPLES): Array<[number, number]>
```

The spiral sample offsets baked into the AO shader: a golden-angle spiral with radii √(i/n), so the taps
spread evenly over the unit disc instead of clustering at the centre the way uniform angles do.

## Types

### `Ssao3dApi`

```ts
interface Ssao3dApi
```

`game.ssao`.

- `radius: number` — Sample radius in world units, live.
- `strength: number` — Darkening strength, live.
- `power: number` — Power curve, live.
- `enabled: boolean` — Turn it off entirely; the cost then is zero.

### `Ssao3dOptions`

```ts
interface Ssao3dOptions
```

How the occlusion looks. Every field is live.

- `radius?: number` — Sample radius in world units. Default 0.8.
- `strength?: number` — Darkening strength, 0..2. Default 1.
- `power?: number` — Power curve; higher tightens the darkening into the creases. Default 1.5.
- `enabled?: boolean` — Whether the pass runs at all. Default true.

---

## For AI agents: Phaser AE

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