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 src="resources/threejs/r102/three.min.js"></script>
  23. <script src="resources/threejs/r102/js/controls/OrbitControls.js"></script>
  24. <script>
  25. 'use strict';
  26. /* global THREE */
  27. function main() {
  28. const canvas = document.querySelector('#c');
  29. const renderer = new THREE.WebGLRenderer({canvas: canvas});
  30. const fov = 75;
  31. const aspect = 2; // the canvas default
  32. const near = 0.1;
  33. const far = 5;
  34. const camera = new THREE.PerspectiveCamera(fov, aspect, near, far);
  35. camera.position.z = 2;
  36. const controls = new THREE.OrbitControls(camera, canvas);
  37. controls.target.set(0, 0, 0);
  38. controls.update();
  39. const scene = new THREE.Scene();
  40. {
  41. const color = 0xFFFFFF;
  42. const intensity = 1;
  43. const light = new THREE.DirectionalLight(color, intensity);
  44. light.position.set(-1, 2, 4);
  45. scene.add(light);
  46. }
  47. const boxWidth = 1;
  48. const boxHeight = 1;
  49. const boxDepth = 1;
  50. const geometry = new THREE.BoxGeometry(boxWidth, boxHeight, boxDepth);
  51. function makeInstance(geometry, color, x) {
  52. const material = new THREE.MeshPhongMaterial({color});
  53. const cube = new THREE.Mesh(geometry, material);
  54. scene.add(cube);
  55. cube.position.x = x;
  56. return cube;
  57. }
  58. makeInstance(geometry, 0x44aa88, 0);
  59. makeInstance(geometry, 0x8844aa, -2);
  60. makeInstance(geometry, 0xaa8844, 2);
  61. function resizeRendererToDisplaySize(renderer) {
  62. const canvas = renderer.domElement;
  63. const width = canvas.clientWidth;
  64. const height = canvas.clientHeight;
  65. const needResize = canvas.width !== width || canvas.height !== height;
  66. if (needResize) {
  67. renderer.setSize(width, height, false);
  68. }
  69. return needResize;
  70. }
  71. function render() {
  72. if (resizeRendererToDisplaySize(renderer)) {
  73. const canvas = renderer.domElement;
  74. camera.aspect = canvas.clientWidth / canvas.clientHeight;
  75. camera.updateProjectionMatrix();
  76. }
  77. renderer.render(scene, camera);
  78. }
  79. render();
  80. controls.addEventListener('change', render);
  81. window.addEventListener('resize', render);
  82. // note: this is a workaround for an OrbitControls issue
  83. // in an iframe. Will remove once the issue is fixed in
  84. // three.js
  85. window.addEventListener('mousedown', (e) => {
  86. e.preventDefault();
  87. window.focus();
  88. });
  89. window.addEventListener('keydown', (e) => {
  90. e.preventDefault();
  91. });
  92. }
  93. main();
  94. </script>
  95. </html>