webgl_buffergeometry_lines_indexed.html 5.6 KB

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249
  1. <!DOCTYPE html>
  2. <html lang="en">
  3. <head>
  4. <title>three.js webgl - buffergeometry - lines - indexed</title>
  5. <meta charset="utf-8">
  6. <meta name="viewport" content="width=device-width, user-scalable=no, minimum-scale=1.0, maximum-scale=1.0">
  7. <link type="text/css" rel="stylesheet" href="main.css">
  8. </head>
  9. <body>
  10. <div id="container"></div>
  11. <div id="info"><a href="https://threejs.org" target="_blank" rel="noopener">three.js</a> webgl - buffergeometry - lines - indexed</div>
  12. <!-- Import maps polyfill -->
  13. <!-- Remove this when import maps will be widely supported -->
  14. <script async src="https://unpkg.com/[email protected]/dist/es-module-shims.js"></script>
  15. <script type="importmap">
  16. {
  17. "imports": {
  18. "three": "../build/three.module.js"
  19. }
  20. }
  21. </script>
  22. <script type="module">
  23. import * as THREE from 'three';
  24. import Stats from './jsm/libs/stats.module.js';
  25. let container, stats;
  26. let camera, scene, renderer;
  27. let parent_node;
  28. init();
  29. animate();
  30. function init() {
  31. container = document.getElementById( 'container' );
  32. camera = new THREE.PerspectiveCamera( 27, window.innerWidth / window.innerHeight, 1, 10000 );
  33. camera.position.z = 9000;
  34. scene = new THREE.Scene();
  35. const geometry = new THREE.BufferGeometry();
  36. const material = new THREE.LineBasicMaterial( { vertexColors: true } );
  37. const indices = [];
  38. const positions = [];
  39. const colors = [];
  40. let next_positions_index = 0;
  41. //
  42. const iteration_count = 4;
  43. const rangle = 60 * Math.PI / 180.0;
  44. function add_vertex( v ) {
  45. if ( next_positions_index == 0xffff ) console.error( 'Too many points.' );
  46. positions.push( v.x, v.y, v.z );
  47. colors.push( Math.random() * 0.5 + 0.5, Math.random() * 0.5 + 0.5, 1 );
  48. return next_positions_index ++;
  49. }
  50. // simple Koch curve
  51. function snowflake_iteration( p0, p4, depth ) {
  52. if ( -- depth < 0 ) {
  53. const i = next_positions_index - 1; // p0 already there
  54. add_vertex( p4 );
  55. indices.push( i, i + 1 );
  56. return;
  57. }
  58. const v = p4.clone().sub( p0 );
  59. const v_tier = v.clone().multiplyScalar( 1 / 3 );
  60. const p1 = p0.clone().add( v_tier );
  61. const angle = Math.atan2( v.y, v.x ) + rangle;
  62. const length = v_tier.length();
  63. const p2 = p1.clone();
  64. p2.x += Math.cos( angle ) * length;
  65. p2.y += Math.sin( angle ) * length;
  66. const p3 = p0.clone().add( v_tier ).add( v_tier );
  67. snowflake_iteration( p0, p1, depth );
  68. snowflake_iteration( p1, p2, depth );
  69. snowflake_iteration( p2, p3, depth );
  70. snowflake_iteration( p3, p4, depth );
  71. }
  72. function snowflake( points, loop, x_offset ) {
  73. for ( let iteration = 0; iteration != iteration_count; iteration ++ ) {
  74. add_vertex( points[ 0 ] );
  75. for ( let p_index = 0, p_count = points.length - 1; p_index != p_count; p_index ++ ) {
  76. snowflake_iteration( points[ p_index ], points[ p_index + 1 ], iteration );
  77. }
  78. if ( loop ) snowflake_iteration( points[ points.length - 1 ], points[ 0 ], iteration );
  79. // translate input curve for next iteration
  80. for ( let p_index = 0, p_count = points.length; p_index != p_count; p_index ++ ) {
  81. points[ p_index ].x += x_offset;
  82. }
  83. }
  84. }
  85. let y = 0;
  86. snowflake(
  87. [
  88. new THREE.Vector3( 0, y, 0 ),
  89. new THREE.Vector3( 500, y, 0 )
  90. ],
  91. false, 600
  92. );
  93. y += 600;
  94. snowflake(
  95. [
  96. new THREE.Vector3( 0, y, 0 ),
  97. new THREE.Vector3( 250, y + 400, 0 ),
  98. new THREE.Vector3( 500, y, 0 )
  99. ],
  100. true, 600
  101. );
  102. y += 600;
  103. snowflake(
  104. [
  105. new THREE.Vector3( 0, y, 0 ),
  106. new THREE.Vector3( 500, y, 0 ),
  107. new THREE.Vector3( 500, y + 500, 0 ),
  108. new THREE.Vector3( 0, y + 500, 0 )
  109. ],
  110. true, 600
  111. );
  112. y += 1000;
  113. snowflake(
  114. [
  115. new THREE.Vector3( 250, y, 0 ),
  116. new THREE.Vector3( 500, y, 0 ),
  117. new THREE.Vector3( 250, y, 0 ),
  118. new THREE.Vector3( 250, y + 250, 0 ),
  119. new THREE.Vector3( 250, y, 0 ),
  120. new THREE.Vector3( 0, y, 0 ),
  121. new THREE.Vector3( 250, y, 0 ),
  122. new THREE.Vector3( 250, y - 250, 0 ),
  123. new THREE.Vector3( 250, y, 0 )
  124. ],
  125. false, 600
  126. );
  127. //
  128. geometry.setIndex( indices );
  129. geometry.setAttribute( 'position', new THREE.Float32BufferAttribute( positions, 3 ) );
  130. geometry.setAttribute( 'color', new THREE.Float32BufferAttribute( colors, 3 ) );
  131. geometry.computeBoundingSphere();
  132. const lineSegments = new THREE.LineSegments( geometry, material );
  133. lineSegments.position.x -= 1200;
  134. lineSegments.position.y -= 1200;
  135. parent_node = new THREE.Object3D();
  136. parent_node.add( lineSegments );
  137. scene.add( parent_node );
  138. renderer = new THREE.WebGLRenderer();
  139. renderer.setPixelRatio( window.devicePixelRatio );
  140. renderer.setSize( window.innerWidth, window.innerHeight );
  141. renderer.outputEncoding = THREE.sRGBEncoding;
  142. container.appendChild( renderer.domElement );
  143. //
  144. stats = new Stats();
  145. container.appendChild( stats.dom );
  146. //
  147. window.addEventListener( 'resize', onWindowResize );
  148. }
  149. function onWindowResize() {
  150. camera.aspect = window.innerWidth / window.innerHeight;
  151. camera.updateProjectionMatrix();
  152. renderer.setSize( window.innerWidth, window.innerHeight );
  153. }
  154. //
  155. function animate() {
  156. requestAnimationFrame( animate );
  157. render();
  158. stats.update();
  159. }
  160. function render() {
  161. const time = Date.now() * 0.001;
  162. parent_node.rotation.z = time * 0.5;
  163. renderer.render( scene, camera );
  164. }
  165. </script>
  166. </body>
  167. </html>