render-on-demand.html 3.1 KB

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  1. <!-- Licensed under a BSD license. See license.html for license -->
  2. <!DOCTYPE html>
  3. <html>
  4. <head>
  5. <meta charset="utf-8">
  6. <meta name="viewport" content="width=device-width, initial-scale=1.0, user-scalable=yes">
  7. <title>Three.js - Rendering on Demand</title>
  8. <style>
  9. html, body {
  10. height: 100%;
  11. margin: 0;
  12. }
  13. #c {
  14. width: 100%;
  15. height: 100%;
  16. display: block;
  17. }
  18. </style>
  19. </head>
  20. <body>
  21. <canvas id="c" tabindex="1"></canvas>
  22. </body>
  23. <!-- Import maps polyfill -->
  24. <!-- Remove this when import maps will be widely supported -->
  25. <script async src="https://unpkg.com/[email protected]/dist/es-module-shims.js"></script>
  26. <script type="importmap">
  27. {
  28. "imports": {
  29. "three": "../../build/three.module.js",
  30. "three/addons/": "../../examples/jsm/"
  31. }
  32. }
  33. </script>
  34. <script type="module">
  35. import * as THREE from 'three';
  36. import {OrbitControls} from 'three/addons/controls/OrbitControls.js';
  37. function main() {
  38. const canvas = document.querySelector('#c');
  39. const renderer = new THREE.WebGLRenderer({antialias: true, canvas});
  40. const fov = 75;
  41. const aspect = 2; // the canvas default
  42. const near = 0.1;
  43. const far = 5;
  44. const camera = new THREE.PerspectiveCamera(fov, aspect, near, far);
  45. camera.position.z = 2;
  46. const controls = new OrbitControls(camera, canvas);
  47. controls.target.set(0, 0, 0);
  48. controls.update();
  49. const scene = new THREE.Scene();
  50. {
  51. const color = 0xFFFFFF;
  52. const intensity = 1;
  53. const light = new THREE.DirectionalLight(color, intensity);
  54. light.position.set(-1, 2, 4);
  55. scene.add(light);
  56. }
  57. const boxWidth = 1;
  58. const boxHeight = 1;
  59. const boxDepth = 1;
  60. const geometry = new THREE.BoxGeometry(boxWidth, boxHeight, boxDepth);
  61. function makeInstance(geometry, color, x) {
  62. const material = new THREE.MeshPhongMaterial({color});
  63. const cube = new THREE.Mesh(geometry, material);
  64. scene.add(cube);
  65. cube.position.x = x;
  66. return cube;
  67. }
  68. makeInstance(geometry, 0x44aa88, 0);
  69. makeInstance(geometry, 0x8844aa, -2);
  70. makeInstance(geometry, 0xaa8844, 2);
  71. function resizeRendererToDisplaySize(renderer) {
  72. const canvas = renderer.domElement;
  73. const width = canvas.clientWidth;
  74. const height = canvas.clientHeight;
  75. const needResize = canvas.width !== width || canvas.height !== height;
  76. if (needResize) {
  77. renderer.setSize(width, height, false);
  78. }
  79. return needResize;
  80. }
  81. function render() {
  82. if (resizeRendererToDisplaySize(renderer)) {
  83. const canvas = renderer.domElement;
  84. camera.aspect = canvas.clientWidth / canvas.clientHeight;
  85. camera.updateProjectionMatrix();
  86. }
  87. renderer.render(scene, camera);
  88. }
  89. render();
  90. controls.addEventListener('change', render);
  91. window.addEventListener('resize', render);
  92. // note: this is a workaround for an OrbitControls issue
  93. // in an iframe. Will remove once the issue is fixed in
  94. // three.js
  95. window.addEventListener('mousedown', (e) => {
  96. e.preventDefault();
  97. window.focus();
  98. });
  99. window.addEventListener('keydown', (e) => {
  100. e.preventDefault();
  101. });
  102. }
  103. main();
  104. </script>
  105. </html>