Body & BodyDesc

A Body is a semantic handle to a rigid body. Create bodies with world.createBody; never construct one directly. For the conceptual overview see Bodies & motion.

Properties

Member	Type	Notes
id	number	Stable id; look up with world.getBody(id).
world	World	The owning world.
userData	unknown	Your metadata (read/write).
valid	boolean	false after removal.

Reading state

All return plain objects; …Into(out) twins write into a caller-owned [x,y,z]/{x,y,z} (or [x,y,z,w]) and return it.

body.translation();  body.translationInto(out);
body.rotation();     body.rotationInto(out);
body.linearVelocity();   body.linearVelocityInto(out);
body.angularVelocity();  body.angularVelocityInto(out);
body.centerOfMassPosition(); body.centerOfMassPositionInto(out);
body.pointVelocity(point);   body.pointVelocityInto(point, out);

Scalar/enum reads:

body.mass();          // number (Infinity for static/kinematic)
body.motionType();    // "static" | "kinematic" | "dynamic"
body.isActive();  body.isSensor();  body.allowSleeping();
body.friction();  body.gravityFactor();

Setting transforms

body.setTranslation(position, options?);
body.setRotation(rotation, options?);
body.setTransform(position, rotation, options?);
body.moveKinematic(position, rotation, deltaTime); // velocity-deriving move

options is { activate?: boolean | "activate" | "dontActivate" }.

Velocities, forces, impulses

body.setLinearVelocity(x, y, z);   // or (vector)
body.setAngularVelocity(x, y, z);
body.applyImpulse(impulse, point?);
body.applyAngularImpulse(impulse);
body.addForce(force, options?, point?);
body.addTorque(torque, options?);

Material & flags

body.setFriction(f);
body.setGravityFactor(g);
body.setAllowSleeping(allow); // false also wakes it
body.setMotionType(type, options?);
body.wakeUp();  body.sleep();

Lifecycle

body.remove();       // = world.removeBody(body); invalidates the wrapper
body.rawUnsafe();    // the raw Jolt body — see the raw-access guide

BodyDesc

A fluent builder passed to createBody. Start one with Body.dynamic(), Body.kinematic(), Body.fixed() (alias Body.static()).

Body.dynamic()
  .shape(Shape.sphere(0.5))
  .translation(0, 8, 0)     // (x, y, z) or (vector)
  .rotation([0, 0, 0, 1])
  .layer("moving")
  .friction(0.6)
  .restitution(0.4)
  .density(500)             // or .mass(n) / .massProperties({...})
  .linearVelocity(1, 0, 0)
  .angularVelocity(0, 2, 0)
  .linearDamping(0.05)
  .angularDamping(0.05)
  .gravityFactor(1)
  .motionQuality("linearCast")
  .allowSleeping(true)
  .sensor()
  .allowedDofs("translation-x", "translation-y", "translation-z")
  .lockRotations()          // shorthand for translation-only
  .userData({ team: "red" });

Every method maps to a CreateBodyOptions field, so the builder and the object form are interchangeable.