Three.js - Canvas Textured Cube

index.html

<canvas id="c"></canvas>
  

script.js

// Three.js - Canvas Textured Cube
// from https://threejsfundamentals.org/threejs/threejs-canvas-textured-cube.html


import * as THREE from 'https://threejsfundamentals.org/threejs/resources/threejs/r127/build/three.module.js';

function main() {
  const canvas = document.querySelector('#c');
  const renderer = new THREE.WebGLRenderer({canvas});

  const fov = 75;
  const aspect = 2;  // the canvas default
  const near = 0.1;
  const far = 5;
  const camera = new THREE.PerspectiveCamera(fov, aspect, near, far);
  camera.position.z = 2;

  const scene = new THREE.Scene();

  const boxWidth = 1;
  const boxHeight = 1;
  const boxDepth = 1;
  const geometry = new THREE.BoxGeometry(boxWidth, boxHeight, boxDepth);

  const cubes = [];  // just an array we can use to rotate the cubes
  const ctx = document.createElement('canvas').getContext('2d');
  ctx.canvas.width = 256;
  ctx.canvas.height = 256;
  ctx.fillStyle = '#FFF';
  ctx.fillRect(0, 0, ctx.canvas.width, ctx.canvas.height);
  const texture = new THREE.CanvasTexture(ctx.canvas);

  const material = new THREE.MeshBasicMaterial({
    map: texture,
  });
  const cube = new THREE.Mesh(geometry, material);
  scene.add(cube);
  cubes.push(cube);  // add to our list of cubes to rotate

  function resizeRendererToDisplaySize(renderer) {
    const canvas = renderer.domElement;
    const width = canvas.clientWidth;
    const height = canvas.clientHeight;
    const needResize = canvas.width !== width || canvas.height !== height;
    if (needResize) {
      renderer.setSize(width, height, false);
    }
    return needResize;
  }

  function randInt(min, max) {
    if (max === undefined) {
      max = min;
      min = 0;
    }
    return Math.random() * (max - min) + min | 0;
  }

  function drawRandomDot() {
    ctx.fillStyle = `#${randInt(0x1000000).toString(16).padStart(6, '0')}`;
    ctx.beginPath();

    const x = randInt(256);
    const y = randInt(256);
    const radius = randInt(10, 64);
    ctx.arc(x, y, radius, 0, Math.PI * 2);
    ctx.fill();
  }

  function render(time) {
    time *= 0.001;

    if (resizeRendererToDisplaySize(renderer)) {
      const canvas = renderer.domElement;
      camera.aspect = canvas.clientWidth / canvas.clientHeight;
      camera.updateProjectionMatrix();
    }

    drawRandomDot();
    texture.needsUpdate = true;

    cubes.forEach((cube, ndx) => {
      const speed = .2 + ndx * .1;
      const rot = time * speed;
      cube.rotation.x = rot;
      cube.rotation.y = rot;
    });

    renderer.render(scene, camera);

    requestAnimationFrame(render);
  }

  requestAnimationFrame(render);
}

main();

style.css

html, body {
  height: 100%;
  margin: 0;
}
#c {
  width: 100%;
  height: 100%;
  display: block;
}

three-js-canvas-textured-cube.markdown

Three.js - Canvas Textured Cube

from: https://threejsfundamentals.org/threejs/threejs-canvas-textured-cube.html

A Pen by Jonathan P Christie on CodePen.

License.