eulerjs API / @eulerjs/core / PhysicsBackend

PhysicsBackend

Defined in: packages/core/src/backend.ts:59

What actually simulates a world. The world, its bodies and joints are the same whatever the backend; the backend keeps its own copy of each body and the world keeps the two in step:

1. before a step, it writes the poses and velocities you changed, wake and sleep requests, and the forces gathered during the step;
2. step simulates;
3. it reads every body's motion and sleep state back.

Backends read a body's settings (type, damping, gravity scale, canSleep, collider materials) and a joint's settings from the objects themselves, so changes to those take effect on the next step. Bodies a joint ties together don't collide with each other while it is in the world if its collideConnected is false. updateBody is called when its mass properties or colliders change.

Properties

Property	Modifier	Type	Description	Defined in
contacts	readonly	readonly Contact[]	The contacts that pushed during the last step, one for each touching point.	packages/core/src/backend.ts:89
name	readonly	string	-	packages/core/src/backend.ts:60
sensorOverlaps	readonly	readonly SensorOverlap[]	Each pair of colliders, one or both a sensor, that overlapped during the last step, among bodies at least one of which was awake.	packages/core/src/backend.ts:91

Methods

addBody()

addBody(body): void;

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

Parameters

Parameter	Type
body	Body

Returns

void

---

addJoint()

addJoint(joint): void;

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

Throws an EulerError for a kind of joint the backend can't simulate.

Parameters

Parameter	Type
joint	Joint

Returns

void

---

applyLoads()

applyLoads(
   body, 
   force, 
   torque
): void;

Defined in: packages/core/src/backend.ts:83

Adds a force through the centre of mass and a torque about it, both in world space, to the next step only.

Parameters

Parameter	Type
body	Body
force	Vector3
torque	Vector3

Returns

void

---

castRay()

castRay(
   origin, 
   direction, 
   maxDistance, 
   filter, 
   all
): QueryHit[];

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

Every collider a ray from origin along the unit direction meets within maxDistance, with where it first meets it, nearest first; only the nearest unless all. Uses the bodies as the backend last had them: the world writes poses you changed before asking.

Parameters

Parameter	Type
origin	Vector3
direction	Vector3
maxDistance	number
filter	QueryFilter
all	boolean

Returns

QueryHit[]

---

castShape()

castShape(
   shape, 
   position, 
   quaternion, 
   direction, 
   maxDistance, 
   filter
): QueryHit | undefined;

Defined in: packages/core/src/backend.ts:99

Where shape, at position turned by quaternion and swept along the unit direction, first touches a collider within maxDistance.

Parameters

Parameter	Type
shape	Collider
position	Vector3
quaternion	Quaternion
direction	Vector3
maxDistance	number
filter	QueryFilter

Returns

QueryHit | undefined

---

dispose()?

optional dispose(): void;

Defined in: packages/core/src/backend.ts:103

Frees whatever the backend holds; called by world.dispose().

Returns

void

---

isSleeping()

isSleeping(body): boolean;

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

Parameters

Parameter	Type
body	Body

Returns

boolean

---

overlap()

overlap(
   shape, 
   position, 
   quaternion, 
   filter
): OverlapHit[];

Defined in: packages/core/src/backend.ts:101

Every collider that shape, at position turned by quaternion, overlaps or touches.

Parameters

Parameter	Type
shape	Collider
position	Vector3
quaternion	Quaternion
filter	QueryFilter

Returns

OverlapHit[]

---

readMotion()

readMotion(body, target): void;

Defined in: packages/core/src/backend.ts:86

Writes the backend's pose and velocities for the body into target.

Parameters

Parameter	Type
body	Body
target	BodyMotion

Returns

void

---

removeBody()

removeBody(body): void;

Defined in: packages/core/src/backend.ts:62

Parameters

Parameter	Type
body	Body

Returns

void

---

removeJoint()

removeJoint(joint): void;

Defined in: packages/core/src/backend.ts:67

Parameters

Parameter	Type
joint	Joint

Returns

void

---

setCollisionsBetween()

setCollisionsBetween(
   bodyA, 
   bodyB, 
   enabled
): void;

Defined in: packages/core/src/backend.ts:73

Stops two bodies colliding with each other, or lets them again. The world calls it at most once each way per pair, and with enabled true for every pair it disabled before either body is removed. Joints with collideConnected false keep their bodies apart on their own.

Parameters

Parameter	Type
bodyA	Body
bodyB	Body
enabled	boolean

Returns

void

---

sleep()

sleep(body): void;

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

Puts the body to sleep now, stopping it.

Parameters

Parameter	Type
body	Body

Returns

void

---

step()

step(settings): void;

Defined in: packages/core/src/backend.ts:84

Parameters

Parameter	Type
settings	StepSettings

Returns

void

---

updateBody()

updateBody(body): void;

Defined in: packages/core/src/backend.ts:64

The body's mass properties or list of colliders changed.

Parameters

Parameter	Type
body	Body

Returns

void

---

wakeUp()

wakeUp(body): void;

Defined in: packages/core/src/backend.ts:79

Wakes the body and restarts its sleep timer, even if it is already awake.

Parameters

Parameter	Type
body	Body

Returns

void

---

writePose()

writePose(body): void;

Defined in: packages/core/src/backend.ts:75

Moves the backend's copy of the body to the body's position and quaternion.

Parameters

Parameter	Type
body	Body

Returns

void

---

writeVelocity()

writeVelocity(body): void;

Defined in: packages/core/src/backend.ts:77

Sets the backend's copy of the body's velocity and angular velocity to the body's.

Parameters

Parameter	Type
body	Body

Returns

void