eulerjs API / @eulerjs/core / Body

Body

Defined in: packages/core/src/Body.ts:137

A rigid body. The body frame is the frame its mass properties are expressed in, normally the local frame of the mesh it was built from. Dynamics happen about the centre of mass; position is the frame's origin, so a bound object's origin lands exactly on it.

Its pose and velocities are yours to read and change, like an Object3D's. Changes take effect when the world next steps; the world writes the backend's results back after every step.

Extends

• RigidBodyState

Constructors

Constructor

new Body(options?): Body;

Defined in: packages/core/src/Body.ts:172

Parameters

Parameter	Type
options?	BodyOptions

Returns

Body

Overrides

RigidBodyState.constructor

Properties

Property	Modifier	Type	Description	Inherited from	Defined in
angularDamping	public	number	-	-	packages/core/src/Body.ts:139
angularVelocity	readonly	Vector3	Angular velocity in world space, in rad/s.	RigidBodyState.angularVelocity	packages/core/src/RigidBodyState.ts:35
canSleep	public	boolean	Whether the body may fall asleep once it has been still for a while.	-	packages/core/src/Body.ts:142
colliders	readonly	readonly Collider[]	The shapes the body collides with. Change them with addCollider and removeCollider.	-	packages/core/src/Body.ts:149
gravityScale	public	number	-	-	packages/core/src/Body.ts:140
instance	readonly	BodyInstance | undefined	The instance of an InstancedMesh that follows the body, if it is drawn as one.	-	packages/core/src/Body.ts:145
linearDamping	public	number	-	-	packages/core/src/Body.ts:138
object	readonly	Object3D<Object3DEventMap> | undefined	-	-	packages/core/src/Body.ts:143
position	readonly	Vector3	Origin of the body frame in world space.	RigidBodyState.position	packages/core/src/RigidBodyState.ts:32
previousPosition	readonly	Vector3	Pose at the start of the last step, used to interpolate rendering between steps.	-	packages/core/src/Body.ts:157
previousQuaternion	readonly	Quaternion	-	-	packages/core/src/Body.ts:158
quaternion	readonly	Quaternion	-	RigidBodyState.quaternion	packages/core/src/RigidBodyState.ts:33
type	readonly	BodyType	-	RigidBodyState.type	packages/core/src/RigidBodyState.ts:55
velocity	readonly	Vector3	Velocity of the centre of mass, in m/s.	RigidBodyState.velocity	packages/core/src/RigidBodyState.ts:34
voxels	readonly	Voxels | undefined	The body's volume as cells, if it was made with them; buoyancy uses it.	-	packages/core/src/Body.ts:147
worldCenterOfMass	readonly	Vector3	Centre of mass in world space, kept in sync with the pose by the world.	RigidBodyState.worldCenterOfMass	packages/core/src/RigidBodyState.ts:37
worldInverseInertia	readonly	Matrix3	Inverse inertia tensor in world space, kept in sync with the pose by the world: how fast an angular impulse turns the body, for working out how hard it is to push at a point. Read it; don't change it.	RigidBodyState.worldInverseInertia	packages/core/src/RigidBodyState.ts:43

Accessors

behaviors

Get Signature

get behaviors(): readonly Behavior[];

Defined in: packages/core/src/Body.ts:273

Returns

readonly Behavior[]

---

inverseMass

Get Signature

get inverseMass(): number;

Defined in: packages/core/src/RigidBodyState.ts:71

1 / mass, or 0 for bodies that forces can't move.

Returns

number

Inherited from

RigidBodyState.inverseMass

---

isDynamic

Get Signature

get isDynamic(): boolean;

Defined in: packages/core/src/RigidBodyState.ts:57

Returns

boolean

Inherited from

RigidBodyState.isDynamic

---

isSleeping

Get Signature

get isSleeping(): boolean;

Defined in: packages/core/src/Body.ts:250

A sleeping body is not simulated until something disturbs it: an awake body running into it, a force, torque or impulse, a new pose or velocity, or wakeUp().

Returns

boolean

---

mass

Get Signature

get mass(): number;

Defined in: packages/core/src/RigidBodyState.ts:66

Total mass in kg, or Infinity for bodies that forces can't move.

Returns

number

Inherited from

RigidBodyState.mass

---

massProperties

Get Signature

get massProperties(): MassProperties | undefined;

Defined in: packages/core/src/RigidBodyState.ts:61

Returns

MassProperties | undefined

Inherited from

RigidBodyState.massProperties

---

world

Get Signature

get world(): World | undefined;

Defined in: packages/core/src/Body.ts:269

Returns

World | undefined

Methods

addBehavior()

addBehavior<SomeBehavior>(behavior): SomeBehavior;

Defined in: packages/core/src/Body.ts:303

Type Parameters

Type Parameter
SomeBehavior extends Behavior

Parameters

Parameter	Type
behavior	SomeBehavior

Returns

SomeBehavior

---

addCollider()

addCollider<SomeCollider>(collider): SomeCollider;

Defined in: packages/core/src/Body.ts:231

Adds a shape to collide with, and wakes the body, since what holds it up may have changed.

Type Parameters

Type Parameter
SomeCollider extends Collider

Parameters

Parameter	Type
collider	SomeCollider

Returns

SomeCollider

---

applyForce()

applyForce(force, worldPoint?): void;

Defined in: packages/core/src/Body.ts:317

Pushes the body for this step. Applied at worldPoint, the force also creates a torque.

Parameters

Parameter	Type
force	Vector3
worldPoint?	Vector3

Returns

void

---

applyForceAtLocalPoint()

applyForceAtLocalPoint(force, localPoint): void;

Defined in: packages/core/src/Body.ts:328

Like applyForce, with the point given in the body's own frame.

Parameters

Parameter	Type
force	Vector3
localPoint	Vector3

Returns

void

---

applyImpulse()

applyImpulse(impulse, worldPoint?): void;

Defined in: packages/core/src/Body.ts:339

Changes the velocity at once, as if impulse (N·s) were delivered at worldPoint.

Parameters

Parameter	Type
impulse	Vector3
worldPoint?	Vector3

Returns

void

---

applyTorque()

applyTorque(torque): void;

Defined in: packages/core/src/Body.ts:332

Parameters

Parameter	Type
torque	Vector3

Returns

void

---

assignMassProperties()

protected assignMassProperties(massProperties): void;

Defined in: packages/core/src/RigidBodyState.ts:123

Sets the mass properties after checking a dynamic body can be moved by them. Doesn't refresh the derived state.

Parameters

Parameter	Type
massProperties	MassProperties

Returns

void

Inherited from

RigidBodyState.assignMassProperties

---

directionToWorld()

directionToWorld(vector): Vector3;

Defined in: packages/core/src/RigidBodyState.ts:102

Rotates a direction from the body frame to world space in place.

Parameters

Parameter	Type
vector	Vector3

Returns

Vector3

Inherited from

RigidBodyState.directionToWorld

---

fromInstances()

static fromInstances(mesh, options?): Body[];

Defined in: packages/core/src/Body.ts:401

Bodies for every instance of mesh, posed as the instances are, colliding as collider says and weighed from the mesh's geometry (or their colliders). world.addInstances does this for you.

Parameters

Parameter	Type
mesh	InstancedMesh
options?	InstancedBodyOptions

Returns

Body[]

---

fromObject()

static fromObject(object, options?): Body;

Defined in: packages/core/src/Body.ts:209

A body for a three.js object, with mass properties computed from its meshes and its starting pose read from it. world.addBody(object, options) does this for you.

Parameters

Parameter	Type
object	Object3D
options?	ObjectBodyOptions

Returns

Body

---

localToWorld()

localToWorld(vector): Vector3;

Defined in: packages/core/src/RigidBodyState.ts:92

Transforms vector from the body frame to world space in place, like Object3D.localToWorld.

Parameters

Parameter	Type
vector	Vector3

Returns

Vector3

Inherited from

RigidBodyState.localToWorld

---

pointToWorld()

pointToWorld(localPoint, target?): Vector3;

Defined in: packages/core/src/RigidBodyState.ts:87

Where a point given in the body frame is in world space, written into target.

Parameters

Parameter	Type
localPoint	Vector3
target?	Vector3

Returns

Vector3

Inherited from

RigidBodyState.pointToWorld

---

pointVelocity()

pointVelocity(worldPoint, target?): Vector3;

Defined in: packages/core/src/RigidBodyState.ts:81

Velocity of the material point of the body currently at worldPoint.

Parameters

Parameter	Type
worldPoint	Vector3
target?	Vector3

Returns

Vector3

Inherited from

RigidBodyState.pointVelocity

---

removeBehavior()

removeBehavior(behavior): void;

Defined in: packages/core/src/Body.ts:309

Parameters

Parameter	Type
behavior	Behavior

Returns

void

---

removeCollider()

removeCollider(collider): void;

Defined in: packages/core/src/Body.ts:239

Removes a shape, and wakes the body, since what holds it up may have changed.

Parameters

Parameter	Type
collider	Collider

Returns

void

---

setMass()

setMass(mass): void;

Defined in: packages/core/src/Body.ts:285

Changes the mass while keeping the shape, so the inertia scales with it.

Parameters

Parameter	Type
mass	number

Returns

void

---

setMassProperties()

setMassProperties(massProperties): void;

Defined in: packages/core/src/Body.ts:278

Replaces the mass properties, and wakes the body.

Parameters

Parameter	Type
massProperties	MassProperties

Returns

void

---

setPose()

setPose(position, quaternion): void;

Defined in: packages/core/src/Body.ts:293

Moves the body instantly, without interpolating from the old pose.

Parameters

Parameter	Type
position	Vector3
quaternion	Quaternion

Returns

void

---

sleep()

sleep(): void;

Defined in: packages/core/src/Body.ts:261

Puts the body to sleep now, stopping it.

Returns

void

---

syncObject()

syncObject(alpha?): void;

Defined in: packages/core/src/Body.ts:358

Writes the pose, interpolated alpha of the way from the previous step, into the bound object or instance.

Parameters

Parameter	Type	Default value
alpha?	number	1

Returns

void

---

wakeUp()

wakeUp(): void;

Defined in: packages/core/src/Body.ts:255

Wakes the body and restarts its sleep timer.

Returns

void

---

worldToLocal()

worldToLocal(vector): Vector3;

Defined in: packages/core/src/RigidBodyState.ts:97

Transforms vector from world space to the body frame in place, like Object3D.worldToLocal.

Parameters

Parameter	Type
vector	Vector3

Returns

Vector3

Inherited from

RigidBodyState.worldToLocal