r3f-animation

React Three Fiber Animation

Quick Start

import { Canvas, useFrame } from '@react-three/fiber'
import { useRef } from 'react'

function RotatingBox() {
  const meshRef = useRef()

  useFrame((state, delta) => {
    meshRef.current.rotation.x += delta
    meshRef.current.rotation.y += delta * 0.5
  })

  return (
    <mesh ref={meshRef}>
      <boxGeometry />
      <meshStandardMaterial color="hotpink" />
    </mesh>
  )
}

export default function App() {
  return (
    <Canvas>
      <ambientLight />
      <RotatingBox />
    </Canvas>
  )
}

useFrame Hook

The core animation hook in R3F. Runs every frame.

Basic Usage

import { useFrame } from '@react-three/fiber'
import { useRef } from 'react'

function AnimatedMesh() {
  const meshRef = useRef()

  useFrame((state, delta) => {
    // state contains: clock, camera, scene, gl, mouse, etc.
    // delta is time since last frame in seconds

    meshRef.current.rotation.y += delta
  })

  return (
    <mesh ref={meshRef}>
      <boxGeometry />
      <meshStandardMaterial color="orange" />
    </mesh>
  )
}

State Object

useFrame((state, delta, xrFrame) => {
  const {
    clock,           // THREE.Clock
    camera,          // Current camera
    scene,           // Scene
    gl,              // WebGLRenderer
    mouse,           // Normalized mouse position (-1 to 1)
    pointer,         // Same as mouse
    viewport,        // Viewport dimensions
    size,            // Canvas size
    raycaster,       // Raycaster
    get,             // Get current state
    set,             // Set state
    invalidate,      // Request re-render (when frameloop="demand")
  } = state

  // Time-based animation
  const t = clock.getElapsedTime()
  meshRef.current.position.y = Math.sin(t) * 2
})

Render Priority

// Lower numbers run first. Default is 0.
// Use negative for pre-render, positive for post-render

function PreRender() {
  useFrame(() => {
    // Runs before main render
  }, -1)
}

function PostRender() {
  useFrame(() => {
    // Runs after main render
  }, 1)
}

function DefaultRender() {
  useFrame(() => {
    // Runs at default priority (0)
  })
}