2
0

billboard-labels-w-sprites.html 5.3 KB

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190
  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 - Billboard Labels w/Sprites</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"></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. }
  31. }
  32. </script>
  33. <script type="module">
  34. import * as THREE from 'three';
  35. import {OrbitControls} from '../../examples/jsm/controls/OrbitControls.js';
  36. function main() {
  37. const canvas = document.querySelector('#c');
  38. const renderer = new THREE.WebGLRenderer({canvas});
  39. const fov = 75;
  40. const aspect = 2; // the canvas default
  41. const near = 0.1;
  42. const far = 50;
  43. const camera = new THREE.PerspectiveCamera(fov, aspect, near, far);
  44. camera.position.set(0, 2, 5);
  45. const controls = new OrbitControls(camera, canvas);
  46. controls.target.set(0, 2, 0);
  47. controls.update();
  48. const scene = new THREE.Scene();
  49. scene.background = new THREE.Color('white');
  50. function addLight(position) {
  51. const color = 0xFFFFFF;
  52. const intensity = 1;
  53. const light = new THREE.DirectionalLight(color, intensity);
  54. light.position.set(...position);
  55. scene.add(light);
  56. scene.add(light.target);
  57. }
  58. addLight([-3, 1, 1]);
  59. addLight([ 2, 1, .5]);
  60. const bodyRadiusTop = .4;
  61. const bodyRadiusBottom = .2;
  62. const bodyHeight = 2;
  63. const bodyRadialSegments = 6;
  64. const bodyGeometry = new THREE.CylinderGeometry(
  65. bodyRadiusTop, bodyRadiusBottom, bodyHeight, bodyRadialSegments);
  66. const headRadius = bodyRadiusTop * 0.8;
  67. const headLonSegments = 12;
  68. const headLatSegments = 5;
  69. const headGeometry = new THREE.SphereGeometry(
  70. headRadius, headLonSegments, headLatSegments);
  71. function makeLabelCanvas(baseWidth, size, name) {
  72. const borderSize = 2;
  73. const ctx = document.createElement('canvas').getContext('2d');
  74. const font = `${size}px bold sans-serif`;
  75. ctx.font = font;
  76. // measure how long the name will be
  77. const textWidth = ctx.measureText(name).width;
  78. const doubleBorderSize = borderSize * 2;
  79. const width = baseWidth + doubleBorderSize;
  80. const height = size + doubleBorderSize;
  81. ctx.canvas.width = width;
  82. ctx.canvas.height = height;
  83. // need to set font again after resizing canvas
  84. ctx.font = font;
  85. ctx.textBaseline = 'middle';
  86. ctx.textAlign = 'center';
  87. ctx.fillStyle = 'blue';
  88. ctx.fillRect(0, 0, width, height);
  89. // scale to fit but don't stretch
  90. const scaleFactor = Math.min(1, baseWidth / textWidth);
  91. ctx.translate(width / 2, height / 2);
  92. ctx.scale(scaleFactor, 1);
  93. ctx.fillStyle = 'white';
  94. ctx.fillText(name, 0, 0);
  95. return ctx.canvas;
  96. }
  97. function makePerson(x, labelWidth, size, name, color) {
  98. const canvas = makeLabelCanvas(labelWidth, size, name);
  99. const texture = new THREE.CanvasTexture(canvas);
  100. // because our canvas is likely not a power of 2
  101. // in both dimensions set the filtering appropriately.
  102. texture.minFilter = THREE.LinearFilter;
  103. texture.wrapS = THREE.ClampToEdgeWrapping;
  104. texture.wrapT = THREE.ClampToEdgeWrapping;
  105. const labelMaterial = new THREE.SpriteMaterial({
  106. map: texture,
  107. transparent: true,
  108. });
  109. const bodyMaterial = new THREE.MeshPhongMaterial({
  110. color,
  111. flatShading: true,
  112. });
  113. const root = new THREE.Object3D();
  114. root.position.x = x;
  115. const body = new THREE.Mesh(bodyGeometry, bodyMaterial);
  116. root.add(body);
  117. body.position.y = bodyHeight / 2;
  118. const head = new THREE.Mesh(headGeometry, bodyMaterial);
  119. root.add(head);
  120. head.position.y = bodyHeight + headRadius * 1.1;
  121. const label = new THREE.Sprite(labelMaterial);
  122. root.add(label);
  123. label.position.y = bodyHeight * 4 / 5;
  124. label.position.z = bodyRadiusTop * 1.01;
  125. // if units are meters then 0.01 here makes size
  126. // of the label into centimeters.
  127. const labelBaseScale = 0.01;
  128. label.scale.x = canvas.width * labelBaseScale;
  129. label.scale.y = canvas.height * labelBaseScale;
  130. scene.add(root);
  131. return root;
  132. }
  133. makePerson(-3, 150, 32, 'Purple People Eater', 'purple');
  134. makePerson(-0, 150, 32, 'Green Machine', 'green');
  135. makePerson(+3, 150, 32, 'Red Menace', 'red');
  136. function resizeRendererToDisplaySize(renderer) {
  137. const canvas = renderer.domElement;
  138. const width = canvas.clientWidth;
  139. const height = canvas.clientHeight;
  140. const needResize = canvas.width !== width || canvas.height !== height;
  141. if (needResize) {
  142. renderer.setSize(width, height, false);
  143. }
  144. return needResize;
  145. }
  146. function render() {
  147. if (resizeRendererToDisplaySize(renderer)) {
  148. const canvas = renderer.domElement;
  149. camera.aspect = canvas.clientWidth / canvas.clientHeight;
  150. camera.updateProjectionMatrix();
  151. }
  152. renderer.render(scene, camera);
  153. requestAnimationFrame(render);
  154. }
  155. requestAnimationFrame(render);
  156. }
  157. main();
  158. </script>
  159. </html>