react-three-cambrian

Version 3.x is out 🎉 🎊 🥳

Find out here about the changes. TLDR: bugfixes, new features, react-native, better types, very few breaking changes (mostly just useRender -> useFrame and apply -> extend).

These demos are real, you can click them! They contain the full code, too.

npm install three react-three-fiber

React-three-fiber is a renderer for Threejs on the web and react-native. Why? Building a dynamic scene graph becomes so much easier when you can break it up into declarative, re-usable, reactive components. It also opens up the ecosystem, you can apply generic packages for state, animation, gestures and so on. This is less of an abstraction and more of a pure reconciler (think react-dom in relation to HTML). It does not target a specific Threejs version nor does it need updates when Threejs alters, adds or removes features, it won't change any specifics or rules, and there are zero limitations.

What it looks like ...

Copy the following into a project to get going. Here's the same running in a code sandbox.

import { Canvas, useFrame } from 'react-three-fiber'
 
function Thing() {
  const ref = useRef()
  useFrame(() => (ref.current.rotation.z += 0.01))
  return (
    <mesh
      ref={ref}
      onClick={e => console.log('click')}
      onPointerOver={e => console.log('hover')}
      onPointerOut={e => console.log('unhover')}>
      <planeBufferGeometry attach="geometry" args={[1, 1]} />
      <meshBasicMaterial attach="material" color="hotpink" opacity={0.5} transparent />
    </mesh>
  )
}
 
<Canvas>
  <Thing />
</Canvas>

Canvas

The Canvas object is your portal into Threejs. It renders Threejs elements, not DOM elements!

<Canvas
  children                      // Either a function child (which receives state) or regular children
  gl                            // Props that go into the default webGL-renderer
  camera                        // Props that go into the default camera
  raycaster                     // Props that go into the default raycaster
  shadowMap                     // Props that go into gl.shadowMap, can also be set true for PCFsoft
  vr = false                    // Switches renderer to VR mode, then uses gl.setAnimationLoop
  orthographic = false          // Creates an orthographic camera if true
  noEvents = false              // Switch off raytracing and event support
  pixelRation = undefined        // You could provide window.devicePixelRatio if you like
  invalidateFrameloop = false   // When true it only renders on changes, when false it's a game loop
  updateDefaultCamera = true    // Adjusts default camera on size changes
  onCreated                     // Callback when vdom is ready (you can block first render via promise)
  onPointerMissed />            // Response for pointer clicks that have missed a target

You can give it additional properties like style and className, which will be added to the container (a div) that holds the dom-canvas element.

Defaults that the canvas component sets up

Canvas will create a translucent WebGL-renderer with the following properties: antialias, alpha, setClearAlpha(0)

A default perspective camera: fov: 75, near: 0.1, far: 1000, position.z: 5

A default orthographic camera if Canvas.orthographic is true: near: 0.1, far: 1000, position.z: 5

A default shadowMap if Canvas.shadowMap is true: type: PCFSoftShadowMap

A default scene (into which all the JSX is rendered) and a raycaster.

You do not have to use any of these objects, look under "receipes" down below if you want to bring your own.

Objects and properties

You can use Threejs's entire object catalogue and all properties. When in doubt, always consult the docs.

You could lay out an object like this:

<mesh
  visible
  userData={{ test: 'hello' }}
  position={new THREE.Vector3(1, 2, 3)}
  rotation={new THREE.Euler(0, 0, 0)}
  geometry={new THREE.SphereGeometry(1, 16, 16)}
  material={new THREE.MeshBasicMaterial({ color: new THREE.Color('hotpink'), transparent: true })}
/>

The problem is that all of these properties will always be re-created. Instead, you should define properties declaratively.

<mesh visible userData={{ test: 'hello' }} position={[1, 2, 3]} rotation={[0, 0, 0]}>
  <sphereGeometry attach="geometry" args={[1, 16, 16]} />
  <meshStandardMaterial attach="material" color="hotpink" transparent />
</mesh>

Shortcuts (set)

All properties that have a .set() method can be given a shortcut. For example THREE.Color.set can take a color string, hence instead of color={new THREE.Color('hotpink')} you can do color="hotpink". Some set methods take multiple arguments (THREE.Vector3.set), so you can pass an array position={[100, 0, 0]}.

Shortcuts and non-Object3D stow-away

Stow away non-Object3D primitives (geometries, materials, etc) into the render tree so that they become managed and reactive. They take the same properties they normally would, constructor arguments are passed with args. Using the attach property objects bind automatically to their parent and are taken off it once they unmount.

You can nest primitive objects, too, which is good for awaiting async textures and such. You could use React-suspense if you wanted!

<meshBasicMaterial attach="material">
  <texture attach="map" image={img} onUpdate={self => img && (self.needsUpdate = true)} />

Sometimes attaching isn't enough. For example, this code attaches effects to an array called "passes" of the parent effectComposer. Note the use of attachArray which adds the object to the target array and takes it out on unmount:

<effectComposer>
  <renderPass attachArray="passes" scene={scene} camera={camera} />
  <glitchPass attachArray="passes" renderToScreen />

You can also attach to named parent properties using attachObject={[target, name]}, which adds the object and takes it out on unmount. The following adds a buffer-attribute to parent.attributes.position.

<bufferGeometry attach="geometry">
  <bufferAttribute attachObject={['attributes', 'position']} count={v.length / 3} array={v} itemSize={3} />

Piercing into nested properties

If you want to reach into nested attributes (for instance: mesh.rotation.x), just use dash-case:

<mesh rotation-x={1} material-uniforms-resolution-value={[1 / size.width, 1 / size.height]} />

Putting already existing objects into the scene-graph

You can use the primitive placeholder for that. You can still give it properties or attach nodes to it.

const mesh = new THREE.Mesh()
return <primitive object={mesh} position={[0, 0, 0]} />

Using 3rd-party (non THREE namespaced) objects in the scene-graph

The extend function extends three-fibers catalogue of known native JSX elements.

import { extend } from 'react-three-fiber'
import { EffectComposer } from 'three/examples/jsm/postprocessing/EffectComposer'
import { RenderPass } from 'three/examples/jsm/postprocessing/RenderPass'
extend({ EffectComposer, RenderPass })
 
<effectComposer>
  <renderPass />

Events

Threejs objects that implement their own raycast method (meshes, lines, etc) can be interacted with by declaring events on the object. We support pointer events (you need to polyfill them yourself), clicks and wheel-scroll. Events contain the browser event as well as the Threejs event data (object, point, distance, etc).

Additionally there's a special onUpdate that is called every time the object gets fresh props, which is good for things like self => (self.verticesNeedUpdate = true).

<mesh
  onClick={e => console.log('click')}
  onWheel={e => console.log('wheel spins')}
  onPointerUp={e => console.log('up')}
  onPointerDown={e => console.log('down')}
  onPointerOver={e => console.log('hover')}
  onPointerOut={e => console.log('unhover')}
  onPointerMove={e => console.log('move')}
  onUpdate={self => console.log('props have been updated')}
/>

Event data

({
  ...DomEvent                   // All the original event data
  ...ThreeEvent                 // All of Three's intersection data
  object: Object3D              // The object that was actually hit
  eventObject: Object3D         // The object that registered the event
  unprojectedPoint: Vector3     // Camera-unprojected point
  ray: Ray                      // The ray that was used to strike the object
  sourceEvent: DomEvent         // A reference to the host event
  delta: number                 // Initial-click delta
}) => ...

Propagation and capturing

  onPointerDown={e => {
    // Only the mesh closest to the camera will be processed
    e.stopPropagation()
    // You may optionally capture the target
    e.target.setPointerCapture(e.pointerId)
  }}
  onPointerUp={e => {
    e.stopPropagation()
    // Optionally release capture
    e.target.releasePointerCapture(e.pointerId)
  }}

Hooks

Hooks can only be used inside the Canvas element because they rely on context! You cannot expect something like this to work:

function App() {
  const { size } = useThree() // This will just crash
  return (
    <Canvas>
      <mesh>

Do this instead:

function SomeComponent() {
  const { size } = useThree()
  return <mesh />
}
 
function App() {
  return (
    <Canvas>
      <SomeComponent />

useThree(): SharedCanvasContext

This hooks gives you access to all the basic objects that are kept internally, like the default renderer, scene, camera. It also gives you the current size of the canvas in screen and viewport coordinates.

import { useThree } from 'react-three-fiber'
 
const {
  gl,                           // WebGL renderer 
  canvas,                       // canvas the dom element that was created
  scene,                        // Default scene
  camera,                       // Default camera
  size,                         // Bounds of the view (which stretches 100% and auto-adjusts)
  viewport,                     // Bounds of the viewport in 3d units + factor (size/viewport)
  aspect,                       // Aspect ratio (size.width / size.height)
  mouse,                        // Current 2D mouse coordinates
  clock,                        // THREE.Clock (usefull for useFrame deltas)
  invalidate,                   // Invalidates a single frame (for <Canvas invalidateFrameloop />)
  intersect,                    // Calls onMouseMove handlers for objects underneath the cursor
  setDefaultCamera,             // Sets the default camera
} = useThree()

useFrame(callback: (state, delta) => void, renderPriority: number = 0)

This hooks calls you back every frame, which is good for running effects, updating controls, etc. You receive the state (same as useThree) and a clock delta. If you supply a render priority greater than zero it will switch off automatic rendering entirely, you can then control rendering yourself. If you have multiple frames with a render priority then they are ordered highest priority last, similar to the web's z-index. Frames are managed, three-fiber will remove them automatically when the component that holds them is unmounted.

Updating controls:

import { useFrame } from 'react-three-fiber'
 
const controls = useRef()
useFrame(state => controls.current.update())
return <orbitControls ref={controls} />

Taking over the render-loop:

useFrame(({ gl, scene, camera }) => gl.render(scene, camera), 1)

useResource(optionalRef=undefined)

When you want to share and re-use resources. useResource creates a ref and re-renders the component when it becomes available next frame.

import { useResource } from 'react-three-fiber'
 
const [ref, material] = useResource()
return (
  <meshBasicMaterial ref={ref} />
  {material && (
    <mesh material={material} />
    <mesh material={material} />
    <mesh material={material} />

useUpdate(callback, dependencies, optionalRef=undefined)

When objects need to be updated imperatively.

import { useUpdate } from 'react-three-fiber'
 
const ref = useUpdate(
  geometry => {
    geometry.addAttribute('position', getVertices(x, y, z))
    geometry.attributes.position.needsUpdate = true
  },
  [x, y, z] // execute only if these properties change
)
return <bufferGeometry ref={ref} />

useLoader(loader, url, [extensions]) (experimental!)

This hooks loads assets and suspends for easier fallback- and error-handling. It returns two values, the asset itself and a look-up-table of props. If you need to lay out GLTF's declaratively check out gltfjsx.

import React, { Suspense } from 'react'
import { useLoader } from 'react-three-fiber'
import { GLTFLoader } from 'three/examples/jsm/loaders/GLTFLoader'
import { DRACOLoader } from 'three/examples/jsm/loaders/DRACOLoader'
 
function Asset({ url }) {
  const [gltf] = useLoader(GLTFLoader, url, loader => {
    const dracoLoader = new DRACOLoader()
    dracoLoader.setDecoderPath('/draco-gltf/')
    loader.setDRACOLoader(dracoLoader)
  })
  return <primitive object={gltf.scene} />
}
 
<Suspense fallback={<Cube />}>
  <Asset url="/spaceship.gltf" />
</Suspense>

Additional exports

import {
  addEffect,                    // Adds a global callback which is called each frame
  invalidate,                   // Forces view global invalidation
  apply,                        // Extends the native-object catalogue
  createPortal,                 // Creates a portal (it's a React feature for re-parenting)
  render,                       // Internal: Renders three jsx into a scene
  unmountComponentAtNode,       // Internal: Unmounts root scene
  applyProps,                   // Internal: Sets element properties
} from 'react-three-fiber'

Further information

Recipes and FAQ: /react-three-fiber/recipes.md

GLTF-to-JSX converter: https://github.com/react-spring/gltfjsx

Learn-with-jason: https://www.youtube.com/watch?v=1rP3nNY2hTo

Contributions

If you like this project, please consider helping out. All contributions are welcome as well as donations to Opencollective, or in crypto:

BTC: 36fuguTPxGCNnYZSRdgdh6Ea94brCAjMbH

ETH: 0x6E3f79Ea1d0dcedeb33D3fC6c34d2B1f156F2682

Sponsors

Backers

Thank you to all our backers! 🙏

Contributors

This project exists thanks to all the people who contribute.