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This tutorial is impressed by Claudio Guglieri’s new non-public website online that accommodates a assortment of playful 3D scenes. What we’ll do in the intervening time is to find the “Don’t” scene that’s composed of rotating mirrors:

We’ll be using Three.js with react-three-fiber v5, drei and use-cannon and we’ll assume that you just’ve some basic data on how one can prepare a scene and work with Three.js.

Since real-time reflections might be terribly performance-heave, we’ll make use of a few neat ideas!

All these libraries are part of Poimandres, a set of libraries for ingenious coding. Adjust to Poimandres on Twitter to get the latest updates:

Drawing sharp textual content material in 3D Space

To make our textual content material look as sharp as attainable, we use drei’s Textual content material factor, which is a wrapper spherical Troika Three Text. This library permits us to draw any webfont using signed distance fields and antialiasing:

import  Textual content material  from '@react-three/drei'

carry out Title() 
   return <Textual content material material-toneMapped=false>My Title</Textual content material>

The `material-toneMapped=false` tells three.js to ignore our supplies when doing tone mapping. Since react-three-fiber v5 makes use of sRGB by default, our textual content material would in another case be further grey than white.


The mirrors are simple Area objects positioned in 3D Space by loading the positions from a JSON file. We use `useResource` to retailer a reference to the provides and re-use them inside the single Mirror parts, meaning we’ll solely event the provides as quickly as.

To make the mirrors come out of the black backdrop, we added a thin film effect by David Lenaerts.

import  useResource  from 'react-three-fiber'

carry out Mirrors( envMap ) 
  const sideMaterial = useResource();
  const reflectionMaterial = useResource();
  const [thinFilmFresnelMap] = useState(new ThinFilmFresnelMap());

  return (
      <meshLambertMaterial ref=sideMaterial map=thinFilmFresnelMap shade=0xaaaaaa />
      <meshLambertMaterial ref=reflectionMaterial map=thinFilmFresnelMap envMap=envMap />, index) => (

For the one mirrors, we assigned a fabric to each face by setting the material prop as an array with 6 values (a fabric for each of the 6 faces of the Area geometry):

carry out Mirror( sideMaterial, reflectionMaterial, args, ...props ) 
  const ref = useRef()

  useFrame(() => 
    ref.current.rotation.y += 0.001
    ref.current.rotation.z += 0.01
  return (
    <Area ...props 

The mirrors are rotated each physique on the y and z axis to create fascinating actions inside the mirrored image.


As you noticed, we’re using an envMap property on our mirror provides. The envMap is used to point reflections on metallic objects. Nevertheless how can we create one for our scene?

Enter cubeCamera, a Three.js object that creates 6 perspective cameras and makes a cube texture out of them:

// 1. we create a CubeRenderTarget
const [renderTarget] = useState(new THREE.WebGLCubeRenderTarget(1024))

// 2. we get a reference to our cubeCamera
const cubeCamera = useRef()
// 3. we substitute the digicam each physique
useFrame(( gl, scene ) => 
  cubeCamera.current.substitute(gl, scene)

return (
     place=[0, 0, 0] 
     // i. uncover how the renderTarget is handed as a constructor argument of the cubeCamera object
     args=[0.1, 100, renderTarget] 

On this basic occasion, we setup cubeCamera that helps us carry the sky reflections on our bodily supplies.

Correct now, our scene doesn’t even have so much else than the mirrors, so we use a magic trick to create fascinating reflections:

carry out TitleCopies( layers ) 
  const vertices = useMemo(() => 
    const y = new THREE.IcosahedronGeometry(8)
    return y.vertices
  , [])

  return <group title="titleCopies">,i) => <Title title="titleCopy-" + i place=vertex layers=layers />)</group>

We create an IcosahedronGeometry (20 faces) and use its vertices to create copies of our title, so that our cubeCamera has one factor to take a look at. To make sure the textual content material is always seen, we moreover make it rotate to take a look on the center of the scene, the place our digicam is positioned.

Since we don’t want the fake textual content material copies to be seen within the major scene, nonetheless solely inside the reflections, we use the layers system of Three.js. 

By assigning layer 11 to our cubeCamera, solely objects that share the equivalent layer might be seen to it. That’s what our cubeCamera goes to see (and thus what we’re going to get on the mirrors).

Satisfying fact: Claudio was kind enough to show us that he moreover used the equivalent methodology to make the reflections further fascinating.

Ending touches

To finish it up, we added a simple mouse interaction that principally helps selling the reflections on the mirrors. We wrapped our full scene in a <group> and animated it using the mouse place:

import  useFrame  from "react-three-fiber";

carry out Scene() 
  const group = useRef();
  const rotationEuler = new THREE.Euler(0, 0, 0);
  const rotationQuaternion = new THREE.Quaternion(0, 0, 0, 0);
  const  viewport  = useThree();

  useFrame(( mouse ) => 
    const x = (mouse.x * viewport.width) / 100;
    const y = (mouse.y * viewport.high) / 100;

    rotationEuler.set(y, x, 0);

    group.current.quaternion.slerp(rotationQuaternion, 0.1);

  return <group ref=group>...</group>;

We create the Euler and Quaternion objects exterior of the useFrame loop, since object creation on every physique would hinder effectivity.
To make a clear rotation, we first set the rotation angle from mouse x and y, then slerp (which sounds humorous nonetheless actually means spherical linear interpolation) the group’s quaternion to our new quaternion.

Bonus Components: Cannon!

Our second variation on this theme contains some simple physics simulation using use-cannon, one different library inside the react-three-fiber’s ecosystem.

For this scene, we setup a wall of cubes that use the equivalent provides setup of our mirrors:

import  useBox  from '@react-three/cannon'

carry out Mirror( envMap, fresnel, ...props ) 
  const [ref, api] = useBox(() => props)
  return (
    <Area ref=ref args=props.args 
      onClick=() => api.applyImpulse([0, 0, -50], [0, 0, 0]) 
      receiveShadow castShadow supplies=[...] 

The useBox hook from use-cannon creates a bodily discipline that’s then sure to the Area mesh using the given ref, that signifies that any change instead of the bodily discipline could even be utilized to our mesh.

We moreover added two bodily planes, one for the bottom and one for the once more wall. Then we solely render the bottom with a ShadowMaterial:

import  usePlane  from '@react-three/cannon'

carry out PhysicalWalls(props) 
  // flooring
  usePlane(() => ( ...props ))

  // once more wall
  usePlane(() => ( place: [0, 0, -20] ))

  return (
    <Airplane args=[1000, 1000] ...props receiveShadow>
      <shadowMaterial clear opacity=0.2 />

To make all of the items magically work, we wrap it inside the <Physics> provider:

import  Physics  from '@react-three/cannon'

<Physics gravity=[0, -10, 0] >
  <Mirrors envMap=renderTarget.texture />
  <PhysicalWalls rotation=[-Math.PI/2, 0, 0] place=[0, -2, 0]/>

Right here’s a simplified mannequin of the bodily scene we used:

And proper right here we go together with some DESTRUCTION:

And in order that … Panna, Olga and Pedro are the names of Gianmarco’s bunny (Panna) and Marco’s cats (Olga and Pedro) 🙂

UI Interactions & Animations Roundup #10


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