---
title: "3D rigid bodies: API"
package: "@phaser-ae/physics-3d"
tier: Free
version: 3.0.0-4
released: 2026-10-14
updated: 2026-10-26
description: "Rigid bodies for 3D games over a Box3D core, with joints, a character controller, vehicles with suspension, triggers, raycasts and explosions."
url: https://phaser.io/packs/physics-3d/api
site: Phaser - https://phaser.io
---

# 3D rigid bodies: API

`@phaser-ae/physics-3d` — Rigid bodies for 3D games over a Box3D core: mass, gravity, friction, joints, a character controller, vehicles, raycasts and triggers.

## The pack

### `physics3d`

```ts
function physics3d(opts: Physics3dOptions = {}): Pack<{ physics3d: Physics3dApi }>
```

The `physics-3d` pack: rigid bodies for a 3D world, over a vendored Box3D core that loads as its own
~1 MB chunk. Requires a 3D world.

## Helpers

### `createRigidWorld3d`

```ts
async function createRigidWorld3d(options:Physics3dOptions={}):Promise<RigidWorld3d>
```

A headless rigid world over the same solver as `game.physics3d`, which you step and dispose yourself. Gravity defaults to −9.81 units/s² (the composed pack uses −20) and substeps to 4. Throws on gravity beyond ±1000 or substeps outside 1 to 32; its `step` throws on a `dt` outside 0 to 0.1 s.

## Functions

### `continuous`

```ts
function continuous(prev: number, next: number): number
```

`next`, shifted by whole turns so it is the SHORT way from `prev`.

The kernel interpolates an object's rotation linearly between fixed steps. A spinning body's yaw crosses
from +π to −π every revolution, and a linear blend across that jump runs the whole way back round — one
frame of a fast reverse spin, once per turn. Keeping the numbers continuous instead of wrapped costs
nothing and makes that blend take the short path by construction.

### `eulerQuat`

```ts
function eulerQuat(yaw: number, pitch: number, roll: number): Quat
```

Euler (the engine's yaw/pitch/roll) → quaternion, in the RENDERER'S OWN composition order.

render-3d's vertex stage computes `rotY(−yaw) · rotX(pitch) · rotZ(roll)`, so the quaternion is
`qy · qx · qz` with the yaw half-angle negated. Get this order wrong and a body simulates correctly while
drawing at some other orientation — which reads as a physics bug and is not one.

### `quatConj`

```ts
function quatConj(q: Quat): Quat
```

The inverse of a unit quaternion.

### `quatFromCols`

```ts
function quatFromCols(cx: V3, cy: V3, cz: V3): Quat
```

A quaternion from an orthonormal basis, the columns being the frame's world axes.

### `quatFromTo`

```ts
function quatFromTo(from: V3, to: V3): Quat
```

The rotation taking unit `from` onto `to`. Handles both poles, where the cross product is useless.

### `quatFromXTo`

```ts
function quatFromXTo(axis: V3): Quat
```

The rotation aiming local +x along `axis`.

### `quatFromZTo`

```ts
function quatFromZTo(axis: V3): Quat
```

The rotation aiming local +z along `axis`.

### `quatMul`

```ts
function quatMul(a: Quat, b: Quat): Quat
```

Quaternion product.

### `quatRotate`

```ts
function quatRotate(q: Quat, p: V3): V3
```

Rotate a point by a quaternion.

### `quatToEuler`

```ts
function quatToEuler(x: number, y: number, z: number, w: number, out: EulerOut): void
```

Quaternion → the engine's yaw/pitch/roll, decomposed in the SAME `rotY(−yaw)·rotX(pitch)·rotZ(roll)` order
the shader applies, so writing these onto an object reproduces the body's exact orientation on screen.

GIMBAL CAVEAT: at pitch = ±90° yaw and roll collapse onto the same axis, so the split between them is
arbitrary there and this puts it all in yaw. A single frame's pose is still exact — every decomposition
renders the right orientation — but a body tumbling THROUGH the pole can see yaw and roll swap values
between frames. That is invisible on screen, because the composed rotation stays continuous; only code
reading the raw numbers of a tumbling body would notice.

## Classes

### `Body3d`

```ts
class Body3d
```

A body bound to an object.

Dynamic bodies OWN their object's transform: steer them with `impulse`, `force` or `velocity`, never by
writing x/y/z (except `teleport`). Kinematic bodies are the reverse — move the OBJECT.

- `readonly target: Body3dTarget` — The object this body drives (dynamic) or follows (kinematic).
- `readonly type: 'dynamic' | 'static' | 'kinematic'` — Which kind of body it is.
- `onHit: ((other: Body3d, speed: number) => void) | null` — Contact above the impact threshold, with the approach speed. Assign at any time.
- `onTouch: ((other: Body3d) => void) | null` — Contact began, any speed.
- `onRelease: ((other: Body3d) => void) | null` — Contact ended.
- `onEnter: ((other: Body3d) => void) | null` — A body entered this trigger.
- `onExit: ((other: Body3d) => void) | null` — A body left this trigger.
- `_id: Id`
- `_sim: Sim`
- `_suspended: boolean`
- `_dead: boolean`
- `constructor(sim: Sim, id: Id, target: Body3dTarget, type: 'dynamic' | 'static' | 'kinematic')`
- `get velocity(): V3` — Linear velocity, world units a second. Set the linear velocity, and wake the body — a velocity set on a sleeping body would otherwise do nothing.
- `set velocity(v: V3)` — Linear velocity, world units a second. Set the linear velocity, and wake the body — a velocity set on a sleeping body would otherwise do nothing.
- `get spin(): V3` — Angular velocity, radians a second per axis. Set the angular velocity, and wake the body.
- `set spin(v: V3)` — Angular velocity, radians a second per axis. Set the angular velocity, and wake the body.
- `get mass(): number` — The body's mass. Static and kinematic bodies read 0.
- `get awake(): boolean` — Is it awake? A sleeping body costs the solver nothing until something touches it. Wake it, or put it to sleep.
- `set awake(v: boolean)` — Is it awake? A sleeping body costs the solver nothing until something touches it. Wake it, or put it to sleep.
- `impulse(v: Partial<V3>, at?: V3): void` — An instant kick, MASS-SCALED so `impulse({ y: 6 })` pops a crate about as high as you would guess whatever it weighs. Pass `at` — a world point — to spin it too: a hit off centre tumbles.
- `force(v: Partial<V3>): void` — A continuous push that accumulates until the next step — thrusters, wind. Mass-scaled like `impulse`.
- `torque(v: Partial<V3>): void` — A twist about the body's centre, in torque units.
- `teleport(position: V3, rotation?: { yaw?: number; pitch?: number; roll?: number }): void` — Move the body and its object instantly, clearing velocity — a respawn. `rotation` is Euler radians in the engine's own yaw/pitch/roll; omitted means upright. It also SNAPS the object, so the frame that follows does not interpolate the jump: without that, a respawn smears the object across the whole map for one frame.
- `destroy(): void` — Take this body out of the world; the object stays where it is. Safe to call twice — the second call does nothing, which matters because the solver RECYCLES body slots and an unguarded double-destroy could kill an unrelated new body.

### `Character3d`

```ts
class Character3d extends Body3d
```

A capsule character controller: a rotation-locked dynamic body with velocity-driven movement. It pushes
crates, rides platforms, climbs shallow steps by capsule shape, and reports `grounded` for jump gating.

- `constructor(sim: Sim, id: Id, target: Body3dTarget, height: number)`
- `move(dir: { x: number; z: number }, speed: number): void` — Steer: set horizontal velocity toward `dir` (any length) at `speed`, keeping vertical motion.
- `get grounded(): boolean` — Standing on something, within a small tolerance below the feet?
- `jump(v: number): boolean` — Jump at takeoff speed `v`. Only fires while grounded; returns whether it did.

## Constants

### `IDENTITY`

```ts
const IDENTITY: Quat
```

The identity rotation.

## Types

### `BindOptions`

```ts
interface BindOptions
```

Options for `bind`.

- `type?: 'dynamic' | 'static' | 'kinematic'` — `'dynamic'` (default) — fully simulated. `'static'` — immovable level geometry. `'kinematic'` — YOU move the object and it pushes dynamic bodies physically (moving platforms, doors on rails).
- `shape?: 'auto' | 'box' | 'sphere' | 'capsule' | 'hull'` — The collision shape: `'auto'` (default — a box of the object's own size), `'sphere'`, `'capsule'` (upright), or `'hull'` (a convex wrap of the `points` you supply — build them with `hull-3d`'s `hullOfVerts`). Match it to what you can see. A hull is CONVEX: a donut's hull is a solid disc.
- `points?: Float32Array` — The `'hull'` shape's point cloud: flat xyz triples in the object's LOCAL unit space, spanning ±0.5 per axis, which the wrapper scales by sx/sy/sz exactly as it derives box half-extents. Required for `shape: 'hull'`; missing or degenerate points fall back to the box.
- `friction?: number` — Surface grip, 0..1+. Default 0.5.
- `bounce?: number` — Bounciness, 0..1. Default 0.
- `rollingResistance?: number` — Rolling resistance, 0..~0.1 — rolling bodies slow down. Default 0, which rolls forever.
- `mass?: number` — Total mass, dynamic bodies. Default: about 1 per cubic unit.
- `group?: string` — Collision group name. Default `'default'`.
- `hits?: string[]` — The group names this body collides with. Default: everything.
- `trigger?: boolean` — Sensor mode: overlaps fire `onEnter`/`onExit` and apply NO contact forces — pickup zones, pressure plates.
- `onEnter?: (other: Body3d) => void` — A body entered this trigger.
- `onExit?: (other: Body3d) => void` — A body left this trigger.
- `onHit?: (other: Body3d, speed: number) => void` — Contact started, above the solver's impact threshold, with the approach speed — gate impact sounds on it.
- `onTouch?: (other: Body3d) => void` — Contact BEGAN at any speed — standing-on bookkeeping, "what am I touching".
- `onRelease?: (other: Body3d) => void` — Contact ENDED — the pair separated.
- `fast?: boolean` — Continuous collision for fast movers, so a bullet does not tunnel through a thin wall.
- `damping?: number` — Linear damping — air drag. Default 0.
- `angularDamping?: number` — Angular damping. Default 0.05.
- `gravityScale?: number` — Gravity multiplier for this body; 0 floats. Default 1.
- `lockRotation?: boolean` — Freeze all rotation — top-down pucks, upright props. Default false.
- `fastSpin?: boolean` — Allow very fast rotation. The solver clamps angular speed by default, which rev-limits a WHEEL. Default false.
- `balance?: V3` — Centre-of-mass offset in the object's LOCAL space. A car with `balance: { y: -0.4 }` carries its weight low like a real one — planted, hard to flip. Default: the geometric centre of the shape.
- `conveyor?: V3` — Conveyor belt: the surface drags whatever rests on it at this velocity while the body itself stays put — usually a static belt. The vector is in the shape's LOCAL space, so rotating the object turns the belt with it. More `friction` is more grip on the cargo.
- `family?: string` — Family name: bodies sharing a family NEVER collide with each other while still colliding with the rest of the world. This is the ragdoll knob — limbs must overlap at their joints without fighting. Independent of `group`/`hits`.

### `Body3dTarget`

```ts
interface Body3dTarget
```

What `bind()` accepts: anything with the pose fields a 3D object has. A kernel `Handle` from
`world3d.spawn()` satisfies it, and so does a plain object in a headless test.

`sx`, `sy` and `sz` are the FULL sizes along each axis — the engine's primitives are unit-sized, so an
object with `sx = 2` really is two units wide. `rot` is yaw; `pitch` and `roll` are the other two, applied
in the renderer's own order.

- `readonly alive?: boolean` — Roster handles expose this; false lets physics release a body whose rendered object was killed.
- `readonly frozen?: boolean` — Scene suspension removes this target from simulation until it resumes.
- `x: number` — Centre x, world units.
- `y: number` — Centre y, world units; y is up.
- `z: number` — Centre z, world units.
- `sx: number` — Full width along x.
- `sy: number` — Full height along y.
- `sz: number` — Full depth along z.
- `rot: number` — Yaw about y, radians.
- `pitch: number` — Pitch about x, radians.
- `roll: number` — Roll about z, radians.

### `Character3dOptions`

```ts
interface Character3dOptions
```

Options for `character`.

- `radius?: number` — Capsule radius. Default 0.4.
- `height?: number` — Total capsule height. Default 1.7.
- `friction?: number` — Ground friction while standing still. Default 0.1 — low, because movement is velocity-driven.
- `group?: string` — Collision group. Default `'characters'`.

### `EulerOut`

```ts
interface EulerOut
```

What {@link quatToEuler} writes into.

- `yaw: number` — Rotation about the vertical axis in radians, with the engine's yaw sign (the renderer applies `rotY(-yaw)`).
- `pitch: number` — Rotation about the x axis in radians, from -π/2 to π/2.
- `roll: number` — Rotation about the z axis in radians; the full turn is applied in the renderer's yaw, pitch, roll composition order.

### `GrabOptions`

```ts
interface GrabOptions
```

Options for `grab` — hold and drive a body relative to another.

- `force?: number` — Max holding force: how heavy a thing it can carry against gravity and knocks. Default 200.
- `torque?: number` — Max holding torque: how firmly it resists spinning away. Default 100.
- `stiffness?: number` — Hold stiffness in Hz. Default 5, which is snappy; lower is a laggy tractor beam.
- `damping?: number` — Hold damping 0..1. Default 0.8.

### `HingeOptions`

```ts
interface HingeOptions
```

Options for `hinge`.

- `at: V3` — The world anchor the hinge turns around.
- `axis?: V3` — The world hinge axis. Default `{ x: 0, y: 1, z: 0 }` — a door.
- `limits?: [number, number]` — Swing limits in radians `[min, max]`. Omit for free spin.
- `motor?: { speed: number; torque?: number }` — Drive it: radians/second, and a torque budget.

### `Joint3d`

```ts
interface Joint3d
```

A joint. Keep the handle to drive its motor or `destroy()` it.

- `motor(speed: number, strength?: number): void` — Retune the motor — a hinge in rad/s, a slider in units/s, a wheel in spin rad/s. No-op on springs and welds.
- `steer?(angle: number): void` — Aim a wheel joint, radians. No-op on the others.
- `drive?(linear: V3, angular?: V3): void` — Grab joints: drive the held body at this relative velocity.
- `destroy(): void` — Remove it; the bodies separate.

### `Physics3dApi`

```ts
interface Physics3dApi
```

`game.physics3d`.

- `readonly ready: Promise<void>` — Resolves once the WASM core has loaded and the world exists. `bind` and every query throw before it, so a scene that uses physics awaits this first: await game.physics3d.ready; game.physics3d.bind(ground, { type: 'static' });
- `readonly live: boolean` — Has the core landed yet?
- `gravity(g: number | V3): void` — Set gravity: a number is straight down, or pass a full vector. Wakes every body.
- `bind(target: Body3dTarget, opts?: BindOptions): Body3d` — Give an object a body. The shape comes from its own size and the pose from where it is NOW.
- `character(target: Body3dTarget, opts?: Character3dOptions): Character3d` — A capsule character controller.
- `bodyOf(target: Body3dTarget): Body3d | null` — The body bound to an object, or null.
- `raycast(origin: V3, dir: V3, maxDistance?: number, ignore?: Body3d, opts?: { hits?: string[] }): RayHit3d | null` — The nearest hit along a ray. `ignore` skips one body — the shooter.
- `raycastAll(origin: V3, dir: V3, maxDistance?: number, opts?: { hits?: string[] }): RayHit3d[]` — Every hit along a ray, nearest first.
- `overlap(center: V3, radius: number, opts?: { hits?: string[] }): Body3d[]` — Every body overlapping a sphere.
- `overlapBox(center: V3, size: V3, opts?: { hits?: string[] }): Body3d[]` — Every body overlapping an axis-aligned box.
- `explosion(at: V3, radius: number, strength: number): void` — A radial blast: a mass-scaled outward kick, with lift, on every dynamic body in range.
- `hinge(a: Body3d, b: Body3d, opts: HingeOptions): Joint3d` — A hinge — doors, windmills, seesaws.
- `socket(a: Body3d, b: Body3d, opts: SocketOptions): Joint3d` — A ball-and-socket — shoulders, hips, chain links.
- `slider(a: Body3d, b: Body3d, opts: SliderOptions): Joint3d` — A slider — elevators, pistons, sliding doors.
- `wheel(chassis: Body3d, wheel: Body3d, opts: WheelOptions): Joint3d` — A vehicle wheel: suspension, drive and steering in one.
- `spring(a: Body3d, b: Body3d, opts?: SpringOptions): Joint3d` — A springy rope — pendulums, cranes, bungees.
- `grab(a: Body3d, b: Body3d, opts?: GrabOptions): Joint3d` — A motorised grip — tractor beams, claws, carrying a crate.
- `weld(a: Body3d, b: Body3d, at?: V3): Joint3d` — Lock two bodies rigidly together.
- `clear(): void` — Remove every body. The objects stay where they are.
- `readonly bodies: number` — How many bodies exist.
- `readonly invalidBodies: number` — Diagnostic: body handles found stale during a step. It should stay 0.
- `enabled: boolean` — Turn the simulation off without tearing it down.

### `Physics3dOptions`

```ts
interface Physics3dOptions
```

Manifest options.

- `gravity?: number | V3` — Gravity: a number is world units/s² straight down, or a full vector. Default −20 (arcade-weighty) for the composed pack; `createRigidWorld3d` defaults to −9.81.
- `substeps?: number` — Solver substeps per fixed step. Default 4; more for taller stacks.
- `module?: string` — Override the core module URL in a development build, on the game's own origin; another origin throws. Rarely needed — the default finds the shipped chunk.

### `Quat`

```ts
interface Quat
```

Box3D's quaternion: a vector part and a scalar.

- `v: V3` — The vector part (x, y, z) of the quaternion, each between -1 and 1 for a unit rotation.
- `s: number` — The scalar part (w), between -1 and 1 for a unit rotation; 1 with a zero vector part is no rotation.

### `RayHit3d`

```ts
interface RayHit3d
```

What a ray found.

- `body: Body3d` — The body it struck.
- `point: V3` — Where, in world units.
- `normal: V3` — The surface normal there.
- `distance: number` — How far along the ray, world units.

### `RigidWorld3d`

```ts
interface RigidWorld3d
```

A renderer-independent rigid world for rule packs and physical replay validation.

- `bind(target:Body3dTarget,options?:BindOptions):Body3d` — Bind a plain owned pose to a real rigid body.
- `hinge(a:Body3d,b:Body3d,options:HingeOptions):Joint3d` — Pin two bodies around a physical rotation axis.
- `step(dt:number):void` — Advance at an explicitly supplied bounded time step.
- `clear():void` — Remove every body and its constraints.
- `reset():void` — Recreate the solver, clearing bodies, contacts and allocation history for deterministic replay.
- `dispose():void` — Release the owned world; repeated disposal is safe.

### `SliderOptions`

```ts
interface SliderOptions
```

Options for `slider`.

- `at: V3` — The world anchor on the slide axis.
- `axis?: V3` — The world slide axis. Default `{ x: 0, y: 1, z: 0 }` — an elevator.
- `limits?: [number, number]` — Travel limits along the axis, world units.
- `motor?: { speed: number; force?: number }` — Drive it: units/second, and a force budget.

### `SocketOptions`

```ts
interface SocketOptions
```

Options for `socket` — a ball-and-socket joint.

- `at: V3` — The world anchor: the ball's centre — a shoulder, a hip, a chain link.
- `axis?: V3` — The rest-pose axis the swing cone opens around; point it along the CHILD limb. Default straight down.
- `swing?: number` — Max swing away from `axis`, radians. Omit for a free ball joint.
- `twist?: [number, number]` — Twist limits about `axis`, radians. Omit for free twist.
- `stiffness?: number` — A soft spring pulling back to the rest pose, in Hz. Adds life to a ragdoll. Default off.

### `SpringOptions`

```ts
interface SpringOptions
```

Options for `spring`.

- `length?: number` — Rest length. Default: the current distance between the anchors.
- `hertz?: number` — Stiffness in Hz — oscillations a second. Default 3.
- `damping?: number` — Damping 0..1; 1 is no wobble. Default 0.35.
- `atA?: V3` — World anchor on body A. Default A's origin.
- `atB?: V3` — World anchor on body B. Default B's origin.

### `V3`

```ts
interface V3
```

A 3D vector, in world units.

- `x: number` — Component along the x axis, in world units.
- `y: number` — Component along the vertical y axis, in world units.
- `z: number` — Component along the z axis, in world units.

### `WheelOptions`

```ts
interface WheelOptions
```

Options for `wheel` — suspension, drive and steering in one joint.

- `at: V3` — The world wheel centre at rest.
- `axle?: V3` — The world axle (spin) axis. Default `{ x: 1, y: 0, z: 0 }` — a car facing ±z.
- `hertz?: number` — Suspension stiffness in Hz. Default 3.5.
- `damping?: number` — Suspension damping 0..1; 1 is no bounce. Default 0.7.
- `travel?: [number, number]` — Suspension travel `[down, up]` around the rest pose. Default `[-0.25, 0.15]`.
- `drive?: boolean | { torque?: number }` — This wheel is powered — `joint.motor(speed)` drives it in rad/s.
- `steer?: boolean | { limit?: number; torque?: number }` — This wheel steers — `joint.steer(angle)` aims it. `limit` caps the lock. Default lock 0.65.

---

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