threejs/threejs-transparency-intersecting-planes-fixed.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 - Transparency - Intersecting Planes Fixed</title>
    <style>
    html, body {
        height: 100%;
        margin: 0;
    }
    #c {
        width: 100%;
        height: 100%;
        display: block;
    }
    </style>
  </head>
  <body>
    <canvas id="c"></canvas>
  </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 = 0.1;
  const far = 25;
  const camera = new THREE.PerspectiveCamera(fov, aspect, near, far);
  camera.position.set(0.5, 1, 0.5);

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

  const scene = new THREE.Scene();
  scene.background = new THREE.Color('white');

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

  const planeWidth = 0.5;
  const planeHeight = 1;
  const geometry = new THREE.PlaneGeometry(planeWidth, planeHeight);

  const loader = new THREE.TextureLoader();

  function makeInstance(geometry, color, rotY, url) {
    const base = new THREE.Object3D();
    scene.add(base);
    base.rotation.y = rotY;

    [-1, 1].forEach((x) => {
      const texture = loader.load(url, render);
      texture.offset.x = x < 0 ? 0 : 0.5;
      texture.repeat.x = .5;
      const material = new THREE.MeshPhongMaterial({
        color,
        map: texture,
        opacity: 0.5,
        transparent: true,
        side: THREE.DoubleSide,
      });

      const mesh = new THREE.Mesh(geometry, material);
      base.add(mesh);

      mesh.position.x = x * .25;
    });
  }

  makeInstance(geometry, 'pink',       0,             'resources/images/happyface.png');  /* threejsfundamentals: url */
  makeInstance(geometry, 'lightblue',  Math.PI * 0.5, 'resources/images/hmmmface.png');   /* threejsfundamentals: url */

  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;
  }

  let renderRequested = false;

  function render() {
    renderRequested = undefined;

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

    renderer.render(scene, camera);
  }
  render();

  function requestRenderIfNotRequested() {
    if (!renderRequested) {
      renderRequested = true;
      requestAnimationFrame(render);
    }
  }

  controls.addEventListener('change', requestRenderIfNotRequested);
  window.addEventListener('resize', requestRenderIfNotRequested);
}

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