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Class: Body

Defined in: src/mobjects/physics/bodies.ts:77

A rigid body in the physics world.

The body is the single source of truth for its motion. An attached mobject follows the body, never the other way around.

Example​

const ball = new Body({
  position: [0, 3],
  shape: { kind: 'circle', radius: 0.2 },
  restitution: 0.8,
});

Constructors​

Constructor​

new Body(options): Body

Defined in: src/mobjects/physics/bodies.ts:103

Parameters​

options​

BodyOptions = {}

Returns​

Body

Properties​

force​

force: Vec2

Defined in: src/mobjects/physics/bodies.ts:83

Force accumulator for the current step, cleared after integration.

gravityScale​

readonly gravityScale: number

Defined in: src/mobjects/physics/bodies.ts:95

Per-body scale on the world gravity.

invMass​

readonly invMass: number

Defined in: src/mobjects/physics/bodies.ts:87

Inverse mass. Zero for a static body, which disables all motion.

isStatic​

readonly isStatic: boolean

Defined in: src/mobjects/physics/bodies.ts:91

Whether the body is static (never moves).

mass​

readonly mass: number

Defined in: src/mobjects/physics/bodies.ts:85

Mass in arbitrary units. A static body reports Infinity.

mobject​

mobject: Mobject

Defined in: src/mobjects/physics/bodies.ts:97

The attached mobject, or null.

position​

position: Vec2

Defined in: src/mobjects/physics/bodies.ts:79

Current position [x, y].

restitution​

readonly restitution: number

Defined in: src/mobjects/physics/bodies.ts:89

Bounciness from 0 to 1.

shape​

readonly shape: BodyShape

Defined in: src/mobjects/physics/bodies.ts:93

The collision shape.

velocity​

velocity: Vec2

Defined in: src/mobjects/physics/bodies.ts:81

Current velocity [x, y] in units/sec.

z​

readonly z: number

Defined in: src/mobjects/physics/bodies.ts:99

The z of the attached mobject at attach time, kept on every move.

Accessors​

radius​

Get Signature​

get radius(): number

Defined in: src/mobjects/physics/bodies.ts:134

The circle radius, or 0 for a polygon body.

Returns​

number

Methods​

aabb()​

aabb(): [number, number, number, number]

Defined in: src/mobjects/physics/bodies.ts:149

The axis-aligned bounds as [minX, minY, maxX, maxY] in world space. A circle uses its radius; a polygon uses its vertex extent.

Returns​

[number, number, number, number]

applyForce()​

applyForce(f): this

Defined in: src/mobjects/physics/bodies.ts:139

Add a force [x, y] to the accumulator for the current step.

Parameters​

f​

Vec2

Returns​

this

reset()​

reset(): this

Defined in: src/mobjects/physics/bodies.ts:175

Restore the position and velocity recorded when the body was created.

Returns​

this