threejs-render-on-demand.html 2.8 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. body {
  10. margin: 0;
  11. }
  12. #c {
  13. width: 100vw;
  14. height: 100vh;
  15. display: block;
  16. }
  17. </style>
  18. </head>
  19. <body>
  20. <canvas id="c" tabindex="1"></canvas>
  21. </body>
  22. <script type="module">
  23. import * as THREE from './resources/threejs/r110/build/three.module.js';
  24. import {OrbitControls} from './resources/threejs/r110/examples/jsm/controls/OrbitControls.js';
  25. function main() {
  26. const canvas = document.querySelector('#c');
  27. const renderer = new THREE.WebGLRenderer({canvas});
  28. const fov = 75;
  29. const aspect = 2; // the canvas default
  30. const near = 0.1;
  31. const far = 5;
  32. const camera = new THREE.PerspectiveCamera(fov, aspect, near, far);
  33. camera.position.z = 2;
  34. const controls = new OrbitControls(camera, canvas);
  35. controls.target.set(0, 0, 0);
  36. controls.update();
  37. const scene = new THREE.Scene();
  38. {
  39. const color = 0xFFFFFF;
  40. const intensity = 1;
  41. const light = new THREE.DirectionalLight(color, intensity);
  42. light.position.set(-1, 2, 4);
  43. scene.add(light);
  44. }
  45. const boxWidth = 1;
  46. const boxHeight = 1;
  47. const boxDepth = 1;
  48. const geometry = new THREE.BoxGeometry(boxWidth, boxHeight, boxDepth);
  49. function makeInstance(geometry, color, x) {
  50. const material = new THREE.MeshPhongMaterial({color});
  51. const cube = new THREE.Mesh(geometry, material);
  52. scene.add(cube);
  53. cube.position.x = x;
  54. return cube;
  55. }
  56. makeInstance(geometry, 0x44aa88, 0);
  57. makeInstance(geometry, 0x8844aa, -2);
  58. makeInstance(geometry, 0xaa8844, 2);
  59. function resizeRendererToDisplaySize(renderer) {
  60. const canvas = renderer.domElement;
  61. const width = canvas.clientWidth;
  62. const height = canvas.clientHeight;
  63. const needResize = canvas.width !== width || canvas.height !== height;
  64. if (needResize) {
  65. renderer.setSize(width, height, false);
  66. }
  67. return needResize;
  68. }
  69. function render() {
  70. if (resizeRendererToDisplaySize(renderer)) {
  71. const canvas = renderer.domElement;
  72. camera.aspect = canvas.clientWidth / canvas.clientHeight;
  73. camera.updateProjectionMatrix();
  74. }
  75. renderer.render(scene, camera);
  76. }
  77. render();
  78. controls.addEventListener('change', render);
  79. window.addEventListener('resize', render);
  80. // note: this is a workaround for an OrbitControls issue
  81. // in an iframe. Will remove once the issue is fixed in
  82. // three.js
  83. window.addEventListener('mousedown', (e) => {
  84. e.preventDefault();
  85. window.focus();
  86. });
  87. window.addEventListener('keydown', (e) => {
  88. e.preventDefault();
  89. });
  90. }
  91. main();
  92. </script>
  93. </html>