threejs/threejs-align-html-to-3d.html

<!-- Licensed under a BSD license. See license.html for license -->
<!DOCTYPE html>
<html>
  <head>
    <meta charset="utf-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0, user-scalable=yes">
    <title>Three.js - Align HTML Elements to 3D</title>
    <style>
    html, body {
        height: 100%;
        margin: 0;
    }
    #c {
        width: 100%;  /* let our container decide our size */
        height: 100%;
        display: block;
    }
    #container {
      position: relative;  /* makes this the origin of its children */
      width: 100%;
      height: 100%;
      overflow: hidden;
    }
    #labels {
      position: absolute;  /* let us position ourself inside the container */
      left: 0;             /* make our position the top left of the container */
      top: 0;
      color: white;
    }
    #labels>div {
      position: absolute;  /* let us position them inside the container */
      left: 0;             /* make their default position the top left of the container */
      top: 0;
      cursor: pointer;     /* change the cursor to a hand when over us */
      font-size: large;
      user-select: none;   /* don't let the text get selected */
      text-shadow:         /* create a black outline */
        -1px -1px 0 #000,
         0   -1px 0 #000,
         1px -1px 0 #000,
         1px  0   0 #000,
         1px  1px 0 #000,
         0    1px 0 #000,
        -1px  1px 0 #000,
        -1px  0   0 #000;
    }
    #labels>div:hover {
      color: red;
    }
    </style>
  </head>
  <body>
    <div id="container">
      <canvas id="c"></canvas>
      <div id="labels"></div>
    </div>
  </body>
<script type="module">
import * as THREE from './resources/threejs/r127/build/three.module.js';
import {OrbitControls} from './resources/threejs/r127/examples/jsm/controls/OrbitControls.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 = 1.1;
  const far = 50;
  const camera = new THREE.PerspectiveCamera(fov, aspect, near, far);
  camera.position.z = 7;

  const controls = new OrbitControls(camera, canvas);
  controls.target.set(0, 0, 0);
  controls.update();

  const scene = new THREE.Scene();

  {
    const color = 0xFFFFFF;
    const intensity = 1;
    const light = new THREE.DirectionalLight(color, intensity);
    light.position.set(-1, 2, 4);
    scene.add(light);
  }

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

  const labelContainerElem = document.querySelector('#labels');

  function makeInstance(geometry, color, x, name) {
    const material = new THREE.MeshPhongMaterial({color});

    const cube = new THREE.Mesh(geometry, material);
    scene.add(cube);

    cube.position.x = x;

    const elem = document.createElement('div');
    elem.textContent = name;
    labelContainerElem.appendChild(elem);

    return {cube, elem};
  }

  const cubes = [
    makeInstance(geometry, 0x44aa88,  0, 'Aqua'),
    makeInstance(geometry, 0x8844aa, -2, 'Purple'),
    makeInstance(geometry, 0xaa8844,  2, 'Gold'),
  ];

  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;
  }

  const tempV = new THREE.Vector3();

  function render(time) {
    time *= 0.001;

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

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

      // get the position of the center of the cube
      cube.updateWorldMatrix(true, false);
      cube.getWorldPosition(tempV);

      // get the normalized screen coordinate of that position
      // x and y will be in the -1 to +1 range with x = -1 being
      // on the left and y = -1 being on the bottom
      tempV.project(camera);

      // convert the normalized position to CSS coordinates
      const x = (tempV.x *  .5 + .5) * canvas.clientWidth;
      const y = (tempV.y * -.5 + .5) * canvas.clientHeight;

      // move the elem to that position
      elem.style.transform = `translate(-50%, -50%) translate(${x}px,${y}px)`;
    });

    renderer.render(scene, camera);

    requestAnimationFrame(render);
  }

  requestAnimationFrame(render);
}

main();
</script>
</html>