Table of Contents

- Installation
- Getting Started
- react-dom
- react-native
- Canvas
- Canvas Props
- Custom Canvas
- Creating Elements
- JSX, properties, and shortcuts
- Setting constructor arguments via args
- Attaching into element properties via attach
- Creating custom elements via extend
- Adding third-party objects via
- Hooks
- Root State
- Accessing state via useOGL
- Frameloop subscriptions via useFrame
- Loading assets via useLoader
- Object traversal via useGraph
- Transient updates via useStore
- Access internals via useInstanceHandle
- Events
- Custom Events
- Portals
- Testing

Installation

``bash


NPM

npm install ogl react-ogl

Yarn

yarn add ogl react-ogl

PNPM

pnpm add ogl react-ogl
`

Getting Started

react-ogl itself is super minimal, but you can use the familiar @react-three/fiber API with some helpers targeted for different platforms:

$3

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

`bash


Create app

npx create-react-app my-app
cd my-app

Install dependencies

npm install ogl react-ogl

Start

npm run start
`

The following creates a re-usable component that has its own state, reacts to events and participates a shared render-loop.

`jsx
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 (
{...props}
ref={mesh}
scale={active ? 1.5 : 1}
onClick={() => setActive((value) => !value)}
onPointerOver={() => setHover(true)}
onPointerOut={() => setHover(false)}
>

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' }}
/>

)
}

createRoot(document.getElementById('root')).render(



,
)
`

$3

This example uses expo-cli but you can create a bare app with react-native CLI as well.

Show full example

`bash


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 start
`

We'll also need to configure metro.config.js to look for the mjs file extension that OGL uses.

`js
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.

`js
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 (
{...props}
ref={mesh}
scale={active ? 1.5 : 1}
onClick={() => setActive((value) => !value)}
onPointerOver={() => setHover(true)}
onPointerOut={() => setHover(false)}
>

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' }}
/>

)
}

export default () => (




)
`

Canvas

react-ogl provides an x-platform 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).

$3

In addition to its platform props, accepts a set of RenderProps to configure react-ogl and its rendering behavior.

`tsx
// 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 /}

// e.g.

renderer={{ alpha: true }}
camera={{ fov: 45, position: [0, 1.3, 3] }}
onCreated={(state) => void state.gl.clearColor(1, 1, 1, 0)}
>


``

$3

A react 18 style createRoot API creates an imperative Root with the same options as , 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).

`jsx
import { createRoot, events } from 'react-ogl'

const canvas = document.querySelector('canvas')
const root = createRoot(canvas, { events })
root.render(



,
)
root.unmount()
`

createRoot can also be used to create a custom . The following constructs a custom canvas that renders its children into react-ogl.

`jsx
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
}
`

Creating elements

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).

`jsx
function Component(props) {
return (




)
}

;


`

These elements are not exported or implemented internally, but merely expressed as JSX — becomes new OGL.Mesh(). This happens dynamically; there's no wrapper involved.

$3

react-ogl elements can be modified with JSX attributes or props. These are native to their underlying OGL objects.

`jsx
// 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}
/>
`

$3

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.

`jsx
// new OGL.Text({ font, text: 'Text' })

`

Built-in elements that require a gl context such as , , or 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:

`jsx




`

and 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.

`jsx

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 /}
vertex={/ glsl / ...}
fragment={/ glsl / ...}
uniforms={{ uniform: value }}
/>

`

$3

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.

`jsx
// Attaches into parent.property, parent.sub.property, and parent.array[0]






// Attaches via parent#setProperty and parent#removeProperty

attach={(parent, self) => {
parent.setProperty(self)
return () => parent.removeProperty(self)
}}
// lambda version
attach={(parent, self) => (parent.setProperty(self), () => parent.removeProperty(self))}
/>

`

Elements who extend OGL.Geometry or OGL.Program will automatically attach via attach="geometry" and attach="program", respectively.

`jsx




`

$3

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.

`jsx
import { extend } from 'react-ogl'

class CustomElement {}
extend({ CustomElement })


`

TypeScript users will need to extend the OGLElements interface to describe custom elements and their properties.

`tsx
import { OGLElement, extend } from 'react-ogl'

class CustomElement {}

declare module 'react-ogl' {
interface OGLElements {
customElement: OGLElement
}
}

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 , , and .

`jsx
import { extend } from 'react-ogl'

class CustomElement {
constructor(gl) {
this.gl = gl
}
}
extend({ CustomElement }, true)


`

$3

Objects created outside of React (e.g. globally or from a loader) can be added to the scene-graph with the element via its object prop. Primitives can be interacted with like any other element, but will modify object and cannot make use of args.

`jsx
import * as OGL from 'ogl'

const object = new OGL.Transform()


`

Hooks

react-ogl ships with hooks that allow you to tie or request information to your components. These are called within the body of and contain imperative and possibly stateful code.

$3

Each 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.

`tsx
interface RootState {
// Zustand setter and getter for live state manipulation.
// See https://github.com/pmndrs/zustand
get(): RootState
set(fn: (previous: RootState) => (next: Partial)): 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.RefObject[]
subscribe: (refCallback: React.RefObject, renderPriority?: number) => void
unsubscribe: (refCallback: React.RefObject, renderPriority?: number) => void
// Optional canvas event manager and its state
events?: EventManager
mouse: OGL.Vec2
raycaster: OGL.Raycast
hovered: Map['object']>
}
`

$3

Returns the current canvas' RootState, describing react-ogl state and OGL rendering internals (see root state).

`tsx
const { renderer, gl, scene, camera, ... } = useOGL()
`

To subscribe to a specific key, useOGL accepts a Zustand selector:

`tsx
const renderer = useOGL((state) => state.renderer)
`

$3

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.

`tsx
const object = React.useRef(null!)

useFrame((state: RootState, time: number, frame?: XRFrame) => {
object.current.rotation.x = time / 2000
object.current.rotation.y = time / 1000
})

return
`

$3

Synchronously loads and caches assets with a loader via suspense. Note: the caller component must be wrapped in React.Suspense.

`jsx
const texture = useLoader(OGL.TextureLoader, '/path/to/image.jpg')
`

Multiple assets can be requested in parallel by passing an array:

`jsx
const [texture1, texture2] = useLoader(OGL.TextureLoader, ['/path/to/image1.jpg', '/path/to/image2.jpg'])
`

Custom loaders can be implemented via the LoaderRepresentation signature:

`tsx
class CustomLoader {
async load(gl: OGLRenderingContext, url: string): Promise {}
}

const result = useLoader(CustomLoader, '/path/to/resource')
`

$3

Traverses an OGL.Transform for unique meshes and programs, returning an ObjectMap.

`tsx
const { nodes, programs } = useGraph(object)


`

$3

Returns the internal Zustand store. Useful for transient updates outside of React (e.g. multiplayer/networking).

`tsx
const store = useStore()
React.useLayoutEffect(() => store.subscribe(state => ...), [store])
`

$3

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.

`tsx
const ref = React.useRef()
const instance = useInstanceHandle(ref)

React.useLayoutEffect(() => {
instance.parent.object.foo()
}, [])


`

Events

react-ogl implements mesh pointer-events with OGL.Raycast that can be tapped into via the following props:

`tsx
// Fired when the mesh is clicked or tapped.
onClick={(event: OGLEvent) => ...}
// Fired when a pointer becomes inactive over the mesh.
onPointerUp={(event: OGLEvent) => ...}
// Fired when a pointer becomes active over the mesh.
onPointerDown={(event: OGLEvent) => ...}
// Fired when a pointer moves over the mesh.
onPointerMove={(event: OGLEvent) => ...}
// Fired when a pointer enters the mesh's bounds.
onPointerOver={(event: OGLEvent) => ...}
// Fired when a pointer leaves the mesh's bounds.
onPointerOut={(event: OGLEvent) => ...}
/>
`

Events contain the original event as nativeEvent and properties from OGL.RaycastHit.

`tsx
{
nativeEvent: PointerEvent | MouseEvent,
localPoint: Vec3,
distance: number,
point: Vec3,
faceNormal: Vec3,
localFaceNormal: Vec3,
uv: Vec2,
localNormal: Vec3,
normal: Vec3,
}
`

$3

Custom events can be implemented per the EventManager interface and passed via the events Canvas prop.

`tsx
const events: EventManager = {
connected: false,
connect(canvas: HTMLCanvasElement, state: RootState) {
// Bind handlers
},
disconnect(canvas: HTMLCanvasElement, state: RootState) {
// Cleanup
},
}


) => console.log(event)}>




`

Full example

`tsx
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['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['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)
}
},
}


) => console.log(event)}>




`

Portals

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.

`tsx
function Component {
// scene & camera are inherited from portal parameters
const { scene, camera, ... } = useOGL()
}

const scene = new OGL.Transform()
const camera = new OGL.Camera()


{createPortal(, scene, { camera })

`

Testing

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).

`tsx
import * as React from 'react'
import * as OGL from 'ogl'
import { type Root, type RootStore, type RootState, createRoot } from 'react-ogl'

it('tests against a react-ogl component or scene', async () => {
const transform = React.createRef()

const root: Root = createRoot(document.createElement('canvas'))
const store: RootStore = await React.act(async () => root.render())
const state: RootState = store.getState()

expect(transform.current).toBeInstanceOf(OGL.Transform)
expect(state.scene.children).toStrictEqual([transform.current])
})
``