<Rigidbody/>

The <Rigidbody/> component gives an <Entity/> physical properties such as mass, velocity, and friction and allows it to interact with the global physics simulation. An <Entity/> with a <Rigidbody/> will respond to gravity, forces, torques and other physics behaviors.

You can learn more about how the physics system works in PlayCanvas in the Physics docs and for React specific details, see the guide on React Physics.

Getting started

ヒント

Using physics in PlayCanvas requires ammo.js and <Application usePhysics/> to be enabled. Run npm i sync-ammo from within your app.

To use the <Rigidbody/> component, you need to install the sync-ammo dependency and you need to add the <Application usePhysics/> prop set in your root <Application/> component. This will enable the physics system and allow your entities to interact with the physics simulation.

Check out the guide on React Physics for more information.

Usage

Add a <Rigidbody/> component to an <Entity/>. You'll also need to add a <Collision/> component to the entity to define the shape of the rigid body.

<Application usePhysics>
  <Entity>
    <Rigidbody type="box" />
  </Entity>
</Application>

Demo

Interactive Physics Example - View Code

Code

rigidbody-example.jsx

// ↑ imports hidden

const Box = ({ color, ...entityProps  }) => {
  const material = useMaterial({ diffuse: color })
  return (
    <Entity {...entityProps}>
      <RigidBody type="dynamic" mass={1} restitution={0.2} friction={0.5} />
      <Collision type="box" />
      <Render type="box" material={material} />
    </Entity>
  )
}

export const RigidbodyExample = () => {
  const [boxes, setBoxes] = useState([
    { id: 1, position: [0, 20, 0], color: '#e74c3c' },
    { id: 2, position: [0.5, 8, 0], color: '#3498db' },
    { id: 3, position: [-0.5, 11, 0], color: '#2ecc71' }
  ])

  const addBox = () => {
    const colors = ['#e74c3c', '#3498db', '#2ecc71', '#f39c12', '#9b59b6', '#1abc9c']
    const color = colors[Math.floor(math.random(0, colors.length))]
    const box = {
      id: Date.now(),
      position: [math.random(-2, 2), 5, math.random(-2, 2)],
      rotation: [math.random(0, 360), math.random(0, 360), math.random(0, 360)],
      color
    }
    setBoxes([...boxes, box])
  }

  return (<>
    {/* Ground plane */}
    <Entity key="ground" position={[0, -0.6, 0]} scale={[10, 0.1, 10]}>
      <RigidBody type="static" friction={0.5} />
      <Collision type="box" halfExtents={[5, 0.1, 5]} />
    </Entity>

    {/* Falling boxes */}
    { boxes.map((props) => <Box key={props.id} {...props} />) }

    {/* UI */}
    <div className="overlay">
      <button onClick={addBox}>Add Box</button>
    </div>
  </>)
}

Learn more about the RigidBody Component in the PlayCanvas documentation.

Properties

Name	Type	Default
type?	"static" | "dynamic" | "kinematic" Sets the rigid body type determines how the body is simulated.	"static"
angularDamping?	number Sets the rate at which a body loses angular velocity over time. Gets the rate at which a body loses angular velocity over time.	-
angularFactor?	[number, number, number] Sets the scaling factor for angular movement of the body in each axis. Only valid for rigid bodies of type BODYTYPE_DYNAMIC. Defaults to 1 in all axes (body can freely rotate). Gets the scaling factor for angular movement of the body in each axis.	-
angularVelocity?	[number, number, number] Sets the rotational speed of the body around each world axis. Gets the rotational speed of the body around each world axis.	-
body?	any	-
friction?	number Sets the friction value used when contacts occur between two bodies. A higher value indicates more friction. Should be set in the range 0 to 1. Defaults to 0.5. Gets the friction value used when contacts occur between two bodies.	-
group?	number Sets the collision group this body belongs to. Combine the group and the mask to prevent bodies colliding with each other. Defaults to 1. Gets the collision group this body belongs to.	-
linearDamping?	number Sets the rate at which a body loses linear velocity over time. Defaults to 0. Gets the rate at which a body loses linear velocity over time.	-
linearFactor?	[number, number, number] Sets the scaling factor for linear movement of the body in each axis. Only valid for rigid bodies of type BODYTYPE_DYNAMIC. Defaults to 1 in all axes (body can freely move). Gets the scaling factor for linear movement of the body in each axis.	-
linearVelocity?	[number, number, number] Sets the speed of the body in a given direction. Gets the speed of the body in a given direction.	-
mask?	number Sets the collision mask sets which groups this body collides with. It is a bit field of 16 bits, the first 8 bits are reserved for engine use. Defaults to 65535. Gets the collision mask sets which groups this body collides with.	-
mass?	number Sets the mass of the body. This is only relevant for BODYTYPE_DYNAMIC bodies, other types have infinite mass. Defaults to 1. Gets the mass of the body.	-
restitution?	number Sets the value that controls the amount of energy lost when two rigid bodies collide. The calculation multiplies the restitution values for both colliding bodies. A multiplied value of 0 means that all energy is lost in the collision while a value of 1 means that no energy is lost. Should be set in the range 0 to 1. Defaults to 0. Gets the value that controls the amount of energy lost when two rigid bodies collide.	-
rollingFriction?	number Sets the torsional friction orthogonal to the contact point. Defaults to 0. Gets the torsional friction orthogonal to the contact point.	-
system?	ComponentSystem The ComponentSystem used to create this Component.	-
entity?	Entity The Entity that this Component is attached to.	-
enabled?	boolean Sets the enabled state of the component. Gets the enabled state of the component.	-