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webgl2_volume_instancing.html 6.4 KB

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  1. <!DOCTYPE html>
  2. <html lang="en">
  3. <head>
  4. <title>three.js webgl2 - volume - instancing</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="info">
  11. <a href="https://threejs.org" target="_blank" rel="noopener">three.js</a> webgl2 - volume - instancing
  12. </div>
  13. <!-- Import maps polyfill -->
  14. <!-- Remove this when import maps will be widely supported -->
  15. <script async src="https://unpkg.com/[email protected]/dist/es-module-shims.js"></script>
  16. <script type="importmap">
  17. {
  18. "imports": {
  19. "three": "../build/three.module.js",
  20. "three/addons/": "./jsm/"
  21. }
  22. }
  23. </script>
  24. <script type="module">
  25. import * as THREE from 'three';
  26. import { OrbitControls } from 'three/addons/controls/OrbitControls.js';
  27. import { VOXLoader, VOXData3DTexture } from 'three/addons/loaders/VOXLoader.js';
  28. import WebGL from 'three/addons/capabilities/WebGL.js';
  29. if ( WebGL.isWebGL2Available() === false ) {
  30. document.body.appendChild( WebGL.getWebGL2ErrorMessage() );
  31. }
  32. let renderer, scene, camera;
  33. let controls;
  34. init();
  35. animate();
  36. function init() {
  37. renderer = new THREE.WebGLRenderer();
  38. renderer.setPixelRatio( window.devicePixelRatio );
  39. renderer.setSize( window.innerWidth, window.innerHeight );
  40. renderer.useLegacyLights = false;
  41. document.body.appendChild( renderer.domElement );
  42. scene = new THREE.Scene();
  43. camera = new THREE.PerspectiveCamera( 60, window.innerWidth / window.innerHeight, 0.1, 1000 );
  44. camera.position.set( 0, 0, 4 );
  45. controls = new OrbitControls( camera, renderer.domElement );
  46. controls.autoRotate = true;
  47. controls.autoRotateSpeed = - 1.0;
  48. controls.enableDamping = true;
  49. // Material
  50. const vertexShader = /* glsl */`
  51. in vec3 position;
  52. in mat4 instanceMatrix;
  53. uniform mat4 modelMatrix;
  54. uniform mat4 modelViewMatrix;
  55. uniform mat4 projectionMatrix;
  56. uniform vec3 cameraPos;
  57. out vec3 vOrigin;
  58. out vec3 vDirection;
  59. void main() {
  60. vec4 mvPosition = modelViewMatrix * instanceMatrix * vec4( position, 1.0 );
  61. vOrigin = vec3( inverse( instanceMatrix * modelMatrix ) * vec4( cameraPos, 1.0 ) ).xyz;
  62. vDirection = position - vOrigin;
  63. gl_Position = projectionMatrix * mvPosition;
  64. }
  65. `;
  66. const fragmentShader = /* glsl */`
  67. precision highp float;
  68. precision highp sampler3D;
  69. uniform mat4 modelViewMatrix;
  70. uniform mat4 projectionMatrix;
  71. in vec3 vOrigin;
  72. in vec3 vDirection;
  73. out vec4 color;
  74. uniform sampler3D map;
  75. uniform float threshold;
  76. uniform float steps;
  77. vec2 hitBox( vec3 orig, vec3 dir ) {
  78. const vec3 box_min = vec3( - 0.5 );
  79. const vec3 box_max = vec3( 0.5 );
  80. vec3 inv_dir = 1.0 / dir;
  81. vec3 tmin_tmp = ( box_min - orig ) * inv_dir;
  82. vec3 tmax_tmp = ( box_max - orig ) * inv_dir;
  83. vec3 tmin = min( tmin_tmp, tmax_tmp );
  84. vec3 tmax = max( tmin_tmp, tmax_tmp );
  85. float t0 = max( tmin.x, max( tmin.y, tmin.z ) );
  86. float t1 = min( tmax.x, min( tmax.y, tmax.z ) );
  87. return vec2( t0, t1 );
  88. }
  89. float sample1( vec3 p ) {
  90. return texture( map, p ).r;
  91. }
  92. #define epsilon .0001
  93. vec3 normal( vec3 coord ) {
  94. if ( coord.x < epsilon ) return vec3( 1.0, 0.0, 0.0 );
  95. if ( coord.y < epsilon ) return vec3( 0.0, 1.0, 0.0 );
  96. if ( coord.z < epsilon ) return vec3( 0.0, 0.0, 1.0 );
  97. if ( coord.x > 1.0 - epsilon ) return vec3( - 1.0, 0.0, 0.0 );
  98. if ( coord.y > 1.0 - epsilon ) return vec3( 0.0, - 1.0, 0.0 );
  99. if ( coord.z > 1.0 - epsilon ) return vec3( 0.0, 0.0, - 1.0 );
  100. float step = 0.01;
  101. float x = sample1( coord + vec3( - step, 0.0, 0.0 ) ) - sample1( coord + vec3( step, 0.0, 0.0 ) );
  102. float y = sample1( coord + vec3( 0.0, - step, 0.0 ) ) - sample1( coord + vec3( 0.0, step, 0.0 ) );
  103. float z = sample1( coord + vec3( 0.0, 0.0, - step ) ) - sample1( coord + vec3( 0.0, 0.0, step ) );
  104. return normalize( vec3( x, y, z ) );
  105. }
  106. void main(){
  107. vec3 rayDir = normalize( vDirection );
  108. vec2 bounds = hitBox( vOrigin, rayDir );
  109. if ( bounds.x > bounds.y ) discard;
  110. bounds.x = max( bounds.x, 0.0 );
  111. vec3 p = vOrigin + bounds.x * rayDir;
  112. vec3 inc = 1.0 / abs( rayDir );
  113. float delta = min( inc.x, min( inc.y, inc.z ) );
  114. delta /= 50.0;
  115. for ( float t = bounds.x; t < bounds.y; t += delta ) {
  116. float d = sample1( p + 0.5 );
  117. if ( d > 0.5 ) {
  118. color.rgb = p * 2.0; // normal( p + 0.5 ); // * 0.5 + ( p * 1.5 + 0.25 );
  119. color.a = 1.;
  120. break;
  121. }
  122. p += rayDir * delta;
  123. }
  124. if ( color.a == 0.0 ) discard;
  125. }
  126. `;
  127. const loader = new VOXLoader();
  128. loader.load( 'models/vox/menger.vox', function ( chunks ) {
  129. for ( let i = 0; i < chunks.length; i ++ ) {
  130. const chunk = chunks[ i ];
  131. const geometry = new THREE.BoxGeometry( 1, 1, 1 );
  132. const material = new THREE.RawShaderMaterial( {
  133. glslVersion: THREE.GLSL3,
  134. uniforms: {
  135. map: { value: new VOXData3DTexture( chunk ) },
  136. cameraPos: { value: new THREE.Vector3() }
  137. },
  138. vertexShader,
  139. fragmentShader,
  140. side: THREE.BackSide
  141. } );
  142. const mesh = new THREE.InstancedMesh( geometry, material, 50000 );
  143. mesh.onBeforeRender = function () {
  144. this.material.uniforms.cameraPos.value.copy( camera.position );
  145. };
  146. const transform = new THREE.Object3D();
  147. for ( let i = 0; i < mesh.count; i ++ ) {
  148. transform.position.random().subScalar( 0.5 ).multiplyScalar( 150 );
  149. transform.rotation.x = Math.random() * Math.PI;
  150. transform.rotation.y = Math.random() * Math.PI;
  151. transform.rotation.z = Math.random() * Math.PI;
  152. transform.updateMatrix();
  153. mesh.setMatrixAt( i, transform.matrix );
  154. }
  155. scene.add( mesh );
  156. }
  157. } );
  158. window.addEventListener( 'resize', onWindowResize );
  159. }
  160. function onWindowResize() {
  161. camera.aspect = window.innerWidth / window.innerHeight;
  162. camera.updateProjectionMatrix();
  163. renderer.setSize( window.innerWidth, window.innerHeight );
  164. }
  165. function animate() {
  166. requestAnimationFrame( animate );
  167. controls.update();
  168. renderer.render( scene, camera );
  169. }
  170. </script>
  171. </body>
  172. </html>