webgl2_volume_cloud.html 8.2 KB

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  1. <!DOCTYPE html>
  2. <html lang="en">
  3. <head>
  4. <title>three.js webgl2 - volume - cloud</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 - cloud
  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 { ImprovedNoise } from 'three/addons/math/ImprovedNoise.js';
  28. import { GUI } from 'three/addons/libs/lil-gui.module.min.js';
  29. import WebGL from 'three/addons/capabilities/WebGL.js';
  30. if ( WebGL.isWebGL2Available() === false ) {
  31. document.body.appendChild( WebGL.getWebGL2ErrorMessage() );
  32. }
  33. let renderer, scene, camera;
  34. let mesh;
  35. init();
  36. animate();
  37. function init() {
  38. renderer = new THREE.WebGLRenderer();
  39. renderer.setPixelRatio( window.devicePixelRatio );
  40. renderer.setSize( window.innerWidth, window.innerHeight );
  41. document.body.appendChild( renderer.domElement );
  42. scene = new THREE.Scene();
  43. camera = new THREE.PerspectiveCamera( 60, window.innerWidth / window.innerHeight, 0.1, 100 );
  44. camera.position.set( 0, 0, 1.5 );
  45. new OrbitControls( camera, renderer.domElement );
  46. // Sky
  47. const canvas = document.createElement( 'canvas' );
  48. canvas.width = 1;
  49. canvas.height = 32;
  50. const context = canvas.getContext( '2d' );
  51. const gradient = context.createLinearGradient( 0, 0, 0, 32 );
  52. gradient.addColorStop( 0.0, '#014a84' );
  53. gradient.addColorStop( 0.5, '#0561a0' );
  54. gradient.addColorStop( 1.0, '#437ab6' );
  55. context.fillStyle = gradient;
  56. context.fillRect( 0, 0, 1, 32 );
  57. const sky = new THREE.Mesh(
  58. new THREE.SphereGeometry( 10 ),
  59. new THREE.MeshBasicMaterial( { map: new THREE.CanvasTexture( canvas ), side: THREE.BackSide } )
  60. );
  61. scene.add( sky );
  62. // Texture
  63. const size = 128;
  64. const data = new Uint8Array( size * size * size );
  65. let i = 0;
  66. const scale = 0.05;
  67. const perlin = new ImprovedNoise();
  68. const vector = new THREE.Vector3();
  69. for ( let z = 0; z < size; z ++ ) {
  70. for ( let y = 0; y < size; y ++ ) {
  71. for ( let x = 0; x < size; x ++ ) {
  72. const d = 1.0 - vector.set( x, y, z ).subScalar( size / 2 ).divideScalar( size ).length();
  73. data[ i ] = ( 128 + 128 * perlin.noise( x * scale / 1.5, y * scale, z * scale / 1.5 ) ) * d * d;
  74. i ++;
  75. }
  76. }
  77. }
  78. const texture = new THREE.Data3DTexture( data, size, size, size );
  79. texture.format = THREE.RedFormat;
  80. texture.minFilter = THREE.LinearFilter;
  81. texture.magFilter = THREE.LinearFilter;
  82. texture.unpackAlignment = 1;
  83. texture.needsUpdate = true;
  84. // Material
  85. const vertexShader = /* glsl */`
  86. in vec3 position;
  87. uniform mat4 modelMatrix;
  88. uniform mat4 modelViewMatrix;
  89. uniform mat4 projectionMatrix;
  90. uniform vec3 cameraPos;
  91. out vec3 vOrigin;
  92. out vec3 vDirection;
  93. void main() {
  94. vec4 mvPosition = modelViewMatrix * vec4( position, 1.0 );
  95. vOrigin = vec3( inverse( modelMatrix ) * vec4( cameraPos, 1.0 ) ).xyz;
  96. vDirection = position - vOrigin;
  97. gl_Position = projectionMatrix * mvPosition;
  98. }
  99. `;
  100. const fragmentShader = /* glsl */`
  101. precision highp float;
  102. precision highp sampler3D;
  103. uniform mat4 modelViewMatrix;
  104. uniform mat4 projectionMatrix;
  105. in vec3 vOrigin;
  106. in vec3 vDirection;
  107. out vec4 color;
  108. uniform vec3 base;
  109. uniform sampler3D map;
  110. uniform float threshold;
  111. uniform float range;
  112. uniform float opacity;
  113. uniform float steps;
  114. uniform float frame;
  115. uint wang_hash(uint seed)
  116. {
  117. seed = (seed ^ 61u) ^ (seed >> 16u);
  118. seed *= 9u;
  119. seed = seed ^ (seed >> 4u);
  120. seed *= 0x27d4eb2du;
  121. seed = seed ^ (seed >> 15u);
  122. return seed;
  123. }
  124. float randomFloat(inout uint seed)
  125. {
  126. return float(wang_hash(seed)) / 4294967296.;
  127. }
  128. vec2 hitBox( vec3 orig, vec3 dir ) {
  129. const vec3 box_min = vec3( - 0.5 );
  130. const vec3 box_max = vec3( 0.5 );
  131. vec3 inv_dir = 1.0 / dir;
  132. vec3 tmin_tmp = ( box_min - orig ) * inv_dir;
  133. vec3 tmax_tmp = ( box_max - orig ) * inv_dir;
  134. vec3 tmin = min( tmin_tmp, tmax_tmp );
  135. vec3 tmax = max( tmin_tmp, tmax_tmp );
  136. float t0 = max( tmin.x, max( tmin.y, tmin.z ) );
  137. float t1 = min( tmax.x, min( tmax.y, tmax.z ) );
  138. return vec2( t0, t1 );
  139. }
  140. float sample1( vec3 p ) {
  141. return texture( map, p ).r;
  142. }
  143. float shading( vec3 coord ) {
  144. float step = 0.01;
  145. return sample1( coord + vec3( - step ) ) - sample1( coord + vec3( step ) );
  146. }
  147. void main(){
  148. vec3 rayDir = normalize( vDirection );
  149. vec2 bounds = hitBox( vOrigin, rayDir );
  150. if ( bounds.x > bounds.y ) discard;
  151. bounds.x = max( bounds.x, 0.0 );
  152. vec3 p = vOrigin + bounds.x * rayDir;
  153. vec3 inc = 1.0 / abs( rayDir );
  154. float delta = min( inc.x, min( inc.y, inc.z ) );
  155. delta /= steps;
  156. // Jitter
  157. // Nice little seed from
  158. // https://blog.demofox.org/2020/05/25/casual-shadertoy-path-tracing-1-basic-camera-diffuse-emissive/
  159. uint seed = uint( gl_FragCoord.x ) * uint( 1973 ) + uint( gl_FragCoord.y ) * uint( 9277 ) + uint( frame ) * uint( 26699 );
  160. vec3 size = vec3( textureSize( map, 0 ) );
  161. float randNum = randomFloat( seed ) * 2.0 - 1.0;
  162. p += rayDir * randNum * ( 1.0 / size );
  163. //
  164. vec4 ac = vec4( base, 0.0 );
  165. for ( float t = bounds.x; t < bounds.y; t += delta ) {
  166. float d = sample1( p + 0.5 );
  167. d = smoothstep( threshold - range, threshold + range, d ) * opacity;
  168. float col = shading( p + 0.5 ) * 3.0 + ( ( p.x + p.y ) * 0.25 ) + 0.2;
  169. ac.rgb += ( 1.0 - ac.a ) * d * col;
  170. ac.a += ( 1.0 - ac.a ) * d;
  171. if ( ac.a >= 0.95 ) break;
  172. p += rayDir * delta;
  173. }
  174. color = ac;
  175. if ( color.a == 0.0 ) discard;
  176. }
  177. `;
  178. const geometry = new THREE.BoxGeometry( 1, 1, 1 );
  179. const material = new THREE.RawShaderMaterial( {
  180. glslVersion: THREE.GLSL3,
  181. uniforms: {
  182. base: { value: new THREE.Color( 0x798aa0 ) },
  183. map: { value: texture },
  184. cameraPos: { value: new THREE.Vector3() },
  185. threshold: { value: 0.25 },
  186. opacity: { value: 0.25 },
  187. range: { value: 0.1 },
  188. steps: { value: 100 },
  189. frame: { value: 0 }
  190. },
  191. vertexShader,
  192. fragmentShader,
  193. side: THREE.BackSide,
  194. transparent: true
  195. } );
  196. mesh = new THREE.Mesh( geometry, material );
  197. scene.add( mesh );
  198. //
  199. const parameters = {
  200. threshold: 0.25,
  201. opacity: 0.25,
  202. range: 0.1,
  203. steps: 100
  204. };
  205. function update() {
  206. material.uniforms.threshold.value = parameters.threshold;
  207. material.uniforms.opacity.value = parameters.opacity;
  208. material.uniforms.range.value = parameters.range;
  209. material.uniforms.steps.value = parameters.steps;
  210. }
  211. const gui = new GUI();
  212. gui.add( parameters, 'threshold', 0, 1, 0.01 ).onChange( update );
  213. gui.add( parameters, 'opacity', 0, 1, 0.01 ).onChange( update );
  214. gui.add( parameters, 'range', 0, 1, 0.01 ).onChange( update );
  215. gui.add( parameters, 'steps', 0, 200, 1 ).onChange( update );
  216. window.addEventListener( 'resize', onWindowResize );
  217. }
  218. function onWindowResize() {
  219. camera.aspect = window.innerWidth / window.innerHeight;
  220. camera.updateProjectionMatrix();
  221. renderer.setSize( window.innerWidth, window.innerHeight );
  222. }
  223. function animate() {
  224. requestAnimationFrame( animate );
  225. mesh.material.uniforms.cameraPos.value.copy( camera.position );
  226. mesh.rotation.y = - performance.now() / 7500;
  227. mesh.material.uniforms.frame.value ++;
  228. renderer.render( scene, camera );
  229. }
  230. </script>
  231. </body>
  232. </html>