# NPM
npm install ogl react-ogl
# Yarn
yarn add ogl react-ogl
# PNPM
pnpm add ogl react-oglreact-ogl itself is super minimal, but you can use the familiar @react-three/fiber API with some helpers targeted for different platforms:
This example uses create-react-app for the sake of simplicity, but you can use your own environment or create a codesandbox.
Show full example
# Create app
npx create-react-app my-app
cd my-app
# Install dependencies
npm install ogl react-ogl
# Start
npm run startThe following creates a re-usable component that has its own state, reacts to events and participates a shared render-loop.
import * as React from 'react'
import { useFrame, Canvas } from 'react-ogl'
import { createRoot } from 'react-dom/client'
function Box(props) {
// This reference will give us direct access to the mesh
const mesh = React.useRef()
// Set up state for the hovered and active state
const [hovered, setHover] = React.useState(false)
const [active, setActive] = React.useState(false)
// Subscribe this component to the render-loop, rotate the mesh every frame
useFrame(() => (mesh.current.rotation.x += 0.01))
// Return view, these are regular OGL elements expressed in JSX
return (
<mesh
{...props}
ref={mesh}
scale={active ? 1.5 : 1}
onClick={() => setActive((value) => !value)}
onPointerOver={() => setHover(true)}
onPointerOut={() => setHover(false)}
>
<box />
<program
vertex={`
attribute vec3 position;
attribute vec3 normal;
uniform mat4 modelViewMatrix;
uniform mat4 projectionMatrix;
uniform mat3 normalMatrix;
varying vec3 vNormal;
void main() {
vNormal = normalize(normalMatrix * normal);
gl_Position = projectionMatrix * modelViewMatrix * vec4(position, 1.0);
}
`}
fragment={`
precision highp float;
uniform vec3 uColor;
varying vec3 vNormal;
void main() {
vec3 normal = normalize(vNormal);
float lighting = dot(normal, normalize(vec3(10)));
gl_FragColor.rgb = uColor + lighting * 0.1;
gl_FragColor.a = 1.0;
}
`}
uniforms={{ uColor: hovered ? 'hotpink' : 'orange' }}
/>
</mesh>
)
}
createRoot(document.getElementById('root')).render(
<Canvas camera={{ position: [0, 0, 8] }}>
<Box position={[-1.2, 0, 0]} />
<Box position={[1.2, 0, 0]} />
</Canvas>,
)This example uses expo-cli but you can create a bare app with react-native CLI as well.
Show full example
# Create app and cd into it
npx expo init my-app # or npx react-native init my-app
cd my-app
# Automatically install & link expo modules
npx install-expo-modules@latest
expo install expo-gl
# Install NPM dependencies
npm install ogl react-ogl
# Start
npm run startWe'll also need to configure metro.config.js to look for the mjs file extension that OGL uses.
module.exports = {
resolver: {
resolverMainFields: ['browser', 'exports', 'main'], // https://github.com/facebook/metro/issues/670
sourceExts: ['json', 'js', 'jsx', 'ts', 'tsx', 'cjs', 'mjs'],
assetExts: ['glb', 'gltf', 'png', 'jpg'],
},
}Inside of our app, you can use the same API as web while running on native OpenGL ES — no webview needed.
import * as React from 'react'
import { useFrame, Canvas } from 'react-ogl'
function Box(props) {
// This reference will give us direct access to the mesh
const mesh = React.useRef()
// Set up state for the hovered and active state
const [hovered, setHover] = React.useState(false)
const [active, setActive] = React.useState(false)
// Subscribe this component to the render-loop, rotate the mesh every frame
useFrame(() => (mesh.current.rotation.x += 0.01))
// Return view, these are regular OGL elements expressed in JSX
return (
<mesh
{...props}
ref={mesh}
scale={active ? 1.5 : 1}
onClick={() => setActive((value) => !value)}
onPointerOver={() => setHover(true)}
onPointerOut={() => setHover(false)}
>
<box />
<program
vertex={`
attribute vec3 position;
attribute vec3 normal;
uniform mat4 modelViewMatrix;
uniform mat4 projectionMatrix;
uniform mat3 normalMatrix;
varying vec3 vNormal;
void main() {
vNormal = normalize(normalMatrix * normal);
gl_Position = projectionMatrix * modelViewMatrix * vec4(position, 1.0);
}
`}
fragment={`
precision highp float;
uniform vec3 uColor;
varying vec3 vNormal;
void main() {
vec3 normal = normalize(vNormal);
float lighting = dot(normal, normalize(vec3(10)));
gl_FragColor.rgb = uColor + lighting * 0.1;
gl_FragColor.a = 1.0;
}
`}
uniforms={{ uColor: hovered ? 'hotpink' : 'orange' }}
/>
</mesh>
)
}
export default () => (
<Canvas camera={{ position: [0, 0, 8] }}>
<Box position={[-1.2, 0, 0]} />
<Box position={[1.2, 0, 0]} />
</Canvas>
)react-ogl provides an x-platform <Canvas /> component for web and native that serves as the entrypoint for your OGL scenes. It is a real DOM canvas or native view that accepts OGL elements as children (see creating elements).
In addition to its platform props, <Canvas /> accepts a set of RenderProps to configure react-ogl and its rendering behavior.
<Canvas
// Configures the react rendering mode. Defaults to `blocking`
mode={"legacy" | "blocking" | "concurrent"}
// Creates, sets, or configures the default renderer.
// Accepts a callback, an external renderer, or renderer constructor params/properties.
// Defaults to `new OGL.Renderer({ alpha: true, antialias: true, powerPreference: 'high-performance' })
renderer={(canvas: HTMLCanvasElement) => new Renderer(canvas) | renderer | { ...params, ...props }}
// Sets the renderer pixel ratio from a clamped range or value. Default is `[1, 2]`
dpr={[min, max] | value}
// Sets or configures the default camera.
// Accepts an external camera, or camera constructor params/properties.
// Defaults to `new OGL.Camera(gl, { fov: 75, near: 1, far: 1000 })` with position-z `5`
camera={camera | { ...params, ...props }}
// Enables orthographic projection when using OGL's built-in camera. Default is `false`
orthographic={true | false}
// Defaults to `always`
frameloop={'always' | 'never'}
// An optional callback invoked after canvas creation and before commit.
onCreated={(state: RootState) => void}
// Optionally configures custom events. Defaults to built-in events exported as `events`
events={EventManager | undefined}
>
{/* Accepts OGL elements as children */}
<transform />
</Canvas>
// e.g.
<Canvas
renderer={{ alpha: true }}
camera={{ fov: 45, position: [0, 1.3, 3] }}
onCreated={(state) => void state.gl.clearColor(1, 1, 1, 0)}
>
<transform />
</Canvas>A react 18 style createRoot API creates an imperative Root with the same options as <Canvas />, but you're responsible for updating it and configuring things like events (see events). This root attaches to an HTMLCanvasElement and renders OGL elements into a scene. Useful for creating an entrypoint with react-ogl and for headless contexts like a server or testing (see testing).
import { createRoot, events } from 'react-ogl'
const canvas = document.querySelector('canvas')
const root = createRoot(canvas, { events })
root.render(
<mesh>
<box />
<normalProgram />
</mesh>,
)
root.unmount()createRoot can also be used to create a custom <Canvas />. The following constructs a custom canvas that renders its children into react-ogl.
import * as React from 'react'
import { createRoot, events } from 'react-ogl'
function CustomCanvas({ children }) {
// Init root from canvas
const [canvas, setCanvas] = React.useState()
const root = React.useMemo(() => canvas && createRoot(canvas, { events }), [canvas])
// Render children as a render-effect
root?.render(children)
// Cleanup on unmount
React.useEffect(() => () => root?.unmount(), [root])
// Use callback-style ref to access canvas in render
return <canvas ref={setCanvas} />
}react-ogl renders React components into an OGL scene-graph, and can be used on top of other renderers like react-dom and react-native that render for web and native, respectively. react-ogl components are defined by primitives or lower-case elements native to the OGL namespace (for custom elements, see extend).
function Component(props) {
return (
<mesh {...props}>
<box />
<normalProgram />
</mesh>
)
}
;<transform>
<Component position={[1, 2, 3]} />
</transform>These elements are not exported or implemented internally, but merely expressed as JSX — <mesh /> becomes new OGL.Mesh(). This happens dynamically; there's no wrapper involved.
react-ogl elements can be modified with JSX attributes or props. These are native to their underlying OGL objects.
<transform
// Set non-atomic properties with literals
// transform.visible = false
visible={false}
// Copy atomic properties with a stable reference (e.g. useMemo)
// transform.rotation.copy(rotation)
rotation={rotation}
// Set atomic properties with declarative array syntax
// transform.position.set(1, 2, 3)
position={[1, 2, 3]}
// Set scalars with shorthand for vector properties
// transform.scale.set(1, 1, 1)
scale={1}
// Set CSS names or hex values as shorthand for color properties
// transform.color.set('red')
color="red"
// Set sub properties with prop piercing or dash-case
// transform.rotation.x = Math.PI / 2
rotation-x={Math.PI / 2}
/>An array of constructor arguments (args) can be passed to instantiate elements' underlying OGL objects. Changing args will reconstruct the object and update any associated refs.
// new OGL.Text({ font, text: 'Text' })
<text args={[{ font, text: 'Text' }]} />Built-in elements that require a gl context such as <mesh />, <geometry />, or <program /> are marked as effectful (see extend) and do not require an OGLRenderingContext to be passed via args. They can be constructed mutably and manipulated via props:
<mesh>
<box />
<normalProgram />
</mesh><geometry /> and <program /> also accept attributes and shader sources as props, which are passed to their respective constructors. This does not affect other properties like drawRange or uniforms.
<mesh>
<geometry
position={{ size: 3, data: new Float32Array([-0.5, 0.5, 0, -0.5, -0.5, 0, 0.5, 0.5, 0, 0.5, -0.5, 0]) }}
uv={{ size: 2, data: new Float32Array([0, 1, 1, 1, 0, 0, 1, 0]) }}
index={{ data: new Uint16Array([0, 1, 2, 1, 3, 2]) }}
/>
{/* prettier-ignore */}
<program
vertex={/* glsl */ `...`}
fragment={/* glsl */ `...`}
uniforms={{ uniform: value }}
/>
</mesh>Some elements do not follow the traditional scene-graph and need to be added by other means. For this, the attach prop can describe where an element is added via a property or a callback to add & remove the element.
// Attaches into parent.property, parent.sub.property, and parent.array[0]
<parent>
<element attach="property" />
<element attach="sub-property" />
<element attach="array-0" />
</parent>
// Attaches via parent#setProperty and parent#removeProperty
<parent>
<element
attach={(parent, self) => {
parent.setProperty(self)
return () => parent.removeProperty(self)
}}
// lambda version
attach={(parent, self) => (parent.setProperty(self), () => parent.removeProperty(self))}
/>
</parent>Elements who extend OGL.Geometry or OGL.Program will automatically attach via attach="geometry" and attach="program", respectively.
<mesh>
<box />
<normalProgram />
</mesh>react-ogl tracks an internal catalog of constructable elements, defaulting to the OGL namespace. This catalog can be expanded via extend to declaratively use custom elements as native elements.
import { extend } from 'react-ogl'
class CustomElement {}
extend({ CustomElement })
<customElement />TypeScript users will need to extend the OGLElements interface to describe custom elements and their properties.
import { OGLElement, extend } from 'react-ogl'
class CustomElement {}
declare module 'react-ogl' {
interface OGLElements {
customElement: OGLElement<typeof CustomElement>
}
}
extend({ CustomElement })Effectful elements that require a gl context can mark themselves as effectful and receive a OGLRenderingContext when constructed, making args mutable and enabling the use of props. This is done for OGL built-in elements like <mesh />, <geometry />, and <program />.
import { extend } from 'react-ogl'
class CustomElement {
constructor(gl) {
this.gl = gl
}
}
extend({ CustomElement }, true)
<customElement />Objects created outside of React (e.g. globally or from a loader) can be added to the scene-graph with the <primitive /> element via its object prop. Primitives can be interacted with like any other element, but will modify object and cannot make use of args.
import * as OGL from 'ogl'
const object = new OGL.Transform()
<primitive object={object} position={[1, 2, 3]} />react-ogl ships with hooks that allow you to tie or request information to your components. These are called within the body of <Canvas /> and contain imperative and possibly stateful code.
Each <Canvas /> or Root encapsulates its own OGL state via React context and a Zustand store, as defined by RootState. This can be accessed and modified with the onCreated canvas prop, and with hooks like useOGL.
interface RootState {
// Zustand setter and getter for live state manipulation.
// See https://github.com/pmndrs/zustand
get(): RootState
set(fn: (previous: RootState) => (next: Partial<RootState>)): void
// Canvas layout information
size: { width: number; height: number }
// OGL scene internals
renderer: OGL.Renderer
gl: OGL.OGLRenderingContext
scene: OGL.Transform
camera: OGL.Camera
// OGL perspective and frameloop preferences
orthographic: boolean
frameloop: 'always' | 'never'
// Internal XR manager to enable WebXR features
xr: XRManager
// Frameloop internals for custom render loops
priority: number
subscribed: React.MutableRefObject<Subscription>[]
subscribe: (refCallback: React.MutableRefObject<Subscription>, renderPriority?: number) => void
unsubscribe: (refCallback: React.MutableRefObject<Subscription>, renderPriority?: number) => void
// Optional canvas event manager and its state
events?: EventManager
mouse: OGL.Vec2
raycaster: OGL.Raycast
hovered: Map<number, Instance<OGL.Mesh>['object']>
}Returns the current canvas' RootState, describing react-ogl state and OGL rendering internals (see root state).
const { renderer, gl, scene, camera, ... } = useOGL()To subscribe to a specific key, useOGL accepts a Zustand selector:
const renderer = useOGL((state) => state.renderer)Subscribes an element into a shared render loop outside of React. useFrame subscriptions are provided a live RootState, the current RaF time in seconds, and a XRFrame when in a WebXR session. Note: useFrame subscriptions should never update React state but prefer external mechanisms like refs.
const object = React.useRef<OGL.Transform>(null!)
useFrame((state: RootState, time: number, frame?: XRFrame) => {
object.current.rotation.x = time / 2000
object.current.rotation.y = time / 1000
})
return <transform ref={object} />Synchronously loads and caches assets with a loader via suspense. Note: the caller component must be wrapped in React.Suspense.
const texture = useLoader(OGL.TextureLoader, '/path/to/image.jpg')Multiple assets can be requested in parallel by passing an array:
const [texture1, texture2] = useLoader(OGL.TextureLoader, ['/path/to/image1.jpg', '/path/to/image2.jpg'])Custom loaders can be implemented via the LoaderRepresentation signature:
class CustomLoader {
async load(gl: OGLRenderingContext, url: string): Promise<void> {}
}
const result = useLoader(CustomLoader, '/path/to/resource')Traverses an OGL.Transform for unique meshes and programs, returning an ObjectMap.
const { nodes, programs } = useGraph(object)
<mesh geometry={nodes['Foo'].geometry} program={programs['Bar']} />Returns the internal Zustand store. Useful for transient updates outside of React (e.g. multiplayer/networking).
const store = useStore()
React.useLayoutEffect(() => store.subscribe(state => ...), [store])Exposes an object's react-internal Instance state from a ref.
Note: this is an escape hatch to react-internal fields. Expect this to change significantly between versions.
const ref = React.useRef<OGL.Transform>()
const instance = useInstanceHandle(ref)
React.useLayoutEffect(() => {
instance.parent.object.foo()
}, [])
<transform ref={ref} />react-ogl implements mesh pointer-events with OGL.Raycast that can be tapped into via the following props:
<mesh
// Fired when the mesh is clicked or tapped.
onClick={(event: OGLEvent<MouseEvent>) => ...}
// Fired when a pointer becomes inactive over the mesh.
onPointerUp={(event: OGLEvent<PointerEvent>) => ...}
// Fired when a pointer becomes active over the mesh.
onPointerDown={(event: OGLEvent<PointerEvent>) => ...}
// Fired when a pointer moves over the mesh.
onPointerMove={(event: OGLEvent<PointerEvent>) => ...}
// Fired when a pointer enters the mesh's bounds.
onPointerOver={(event: OGLEvent<PointerEvent>) => ...}
// Fired when a pointer leaves the mesh's bounds.
onPointerOut={(event: OGLEvent<PointerEvent>) => ...}
/>Events contain the original event as nativeEvent and properties from OGL.RaycastHit.
{
nativeEvent: PointerEvent | MouseEvent,
localPoint: Vec3,
distance: number,
point: Vec3,
faceNormal: Vec3,
localFaceNormal: Vec3,
uv: Vec2,
localNormal: Vec3,
normal: Vec3,
}Custom events can be implemented per the EventManager interface and passed via the events Canvas prop.
const events: EventManager = {
connected: false,
connect(canvas: HTMLCanvasElement, state: RootState) {
// Bind handlers
},
disconnect(canvas: HTMLCanvasElement, state: RootState) {
// Cleanup
},
}
<Canvas events={events}>
<mesh onPointerMove={(event: OGLEvent<PointerEvent>) => console.log(event)}>
<box />
<normalProgram />
</mesh>
</Canvas>Full example
const events = {
connected: false,
connect(canvas: HTMLCanvasElement, state: RootState) {
state.events.handlers = {
pointermove(event: PointerEvent) {
// Convert mouse coordinates
state.mouse.x = (event.offsetX / state.size.width) * 2 - 1
state.mouse.y = -(event.offsetY / state.size.height) * 2 + 1
// Filter to interactive meshes
const interactive: OGL.Mesh[] = []
state.scene.traverse((node: OGL.Transform) => {
// Mesh has registered events and a defined volume
if (
node instanceof OGL.Mesh &&
(node as Instance<OGL.Mesh>['object']).__handlers &&
node.geometry?.attributes?.position
)
interactive.push(node)
})
// Get elements that intersect with our pointer
state.raycaster!.castMouse(state.camera, state.mouse)
const intersects: OGL.Mesh[] = state.raycaster!.intersectMeshes(interactive)
// Call mesh handlers
for (const entry of intersects) {
if ((entry as unknown as any).__handlers) {
const object = entry as Instance<OGL.Mesh>['object']
const handlers = object.__handlers
const handlers = object.__handlers
handlers?.onPointerMove?.({ ...object.hit, nativeEvent: event })
}
}
},
}
// Bind
state.events.connected = true
for (const [name, handler] of Object.entries(state.events.handlers)) {
canvas.addEventListener(name, handler)
}
},
disconnect(canvas: HTMLCanvasElement, state: RootState) {
// Unbind
state.events.connected = false
for (const [name, handler] of Object.entries(state.events.handlers)) {
canvas.removeEventListener(name, handler)
}
},
}
<Canvas events={events}>
<mesh onPointerMove={(event: OGLEvent<PointerEvent>) => console.log(event)}>
<box />
<normalProgram />
</mesh>
</Canvas>Portal children into a foreign OGL element via createPortal, which can modify children's RootState. This is particularly useful for postprocessing and complex render effects.
function Component {
// scene & camera are inherited from portal parameters
const { scene, camera, ... } = useOGL()
}
const scene = new OGL.Transform()
const camera = new OGL.Camera()
<transform>
{createPortal(<Component />, scene, { camera })
</transform>In addition to createRoot (see custom canvas), react-ogl exports an act method which can be used to safely flush async effects in tests. The following emulates a legacy root and asserts against RootState (see root state).
import * as React from 'react'
import * as OGL from 'ogl'
import { type Root, type RootStore, type RootState, createRoot, act } from 'react-ogl'
it('tests against a react-ogl component or scene', async () => {
const transform = React.createRef<OGL.Transform>()
const root: Root = createRoot(document.createElement('canvas'))
const store: RootStore = await act(async () => root.render(<transform ref={transform} />))
const state: RootState = store.getState()
expect(transform.current).toBeInstanceOf(OGL.Transform)
expect(state.scene.children).toStrictEqual([transform.current])
})
