webgl_volume_cloud.html 8.2 KB

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270271272273274275276277278279280281282283284285286287288289290291292293294295296297298299300301302303304305306307308309310311312313314315316
  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. <script type="importmap">
  14. {
  15. "imports": {
  16. "three": "../build/three.module.js",
  17. "three/addons/": "./jsm/"
  18. }
  19. }
  20. </script>
  21. <script type="module">
  22. import * as THREE from 'three';
  23. import { OrbitControls } from 'three/addons/controls/OrbitControls.js';
  24. import { ImprovedNoise } from 'three/addons/math/ImprovedNoise.js';
  25. import { GUI } from 'three/addons/libs/lil-gui.module.min.js';
  26. let renderer, scene, camera;
  27. let mesh;
  28. init();
  29. function init() {
  30. renderer = new THREE.WebGLRenderer();
  31. renderer.setPixelRatio( window.devicePixelRatio );
  32. renderer.setSize( window.innerWidth, window.innerHeight );
  33. renderer.setAnimationLoop( animate );
  34. document.body.appendChild( renderer.domElement );
  35. scene = new THREE.Scene();
  36. camera = new THREE.PerspectiveCamera( 60, window.innerWidth / window.innerHeight, 0.1, 100 );
  37. camera.position.set( 0, 0, 1.5 );
  38. new OrbitControls( camera, renderer.domElement );
  39. // Sky
  40. const canvas = document.createElement( 'canvas' );
  41. canvas.width = 1;
  42. canvas.height = 32;
  43. const context = canvas.getContext( '2d' );
  44. const gradient = context.createLinearGradient( 0, 0, 0, 32 );
  45. gradient.addColorStop( 0.0, '#014a84' );
  46. gradient.addColorStop( 0.5, '#0561a0' );
  47. gradient.addColorStop( 1.0, '#437ab6' );
  48. context.fillStyle = gradient;
  49. context.fillRect( 0, 0, 1, 32 );
  50. const skyMap = new THREE.CanvasTexture( canvas );
  51. skyMap.colorSpace = THREE.SRGBColorSpace;
  52. const sky = new THREE.Mesh(
  53. new THREE.SphereGeometry( 10 ),
  54. new THREE.MeshBasicMaterial( { map: skyMap, side: THREE.BackSide } )
  55. );
  56. scene.add( sky );
  57. // Texture
  58. const size = 128;
  59. const data = new Uint8Array( size * size * size );
  60. let i = 0;
  61. const scale = 0.05;
  62. const perlin = new ImprovedNoise();
  63. const vector = new THREE.Vector3();
  64. for ( let z = 0; z < size; z ++ ) {
  65. for ( let y = 0; y < size; y ++ ) {
  66. for ( let x = 0; x < size; x ++ ) {
  67. const d = 1.0 - vector.set( x, y, z ).subScalar( size / 2 ).divideScalar( size ).length();
  68. data[ i ] = ( 128 + 128 * perlin.noise( x * scale / 1.5, y * scale, z * scale / 1.5 ) ) * d * d;
  69. i ++;
  70. }
  71. }
  72. }
  73. const texture = new THREE.Data3DTexture( data, size, size, size );
  74. texture.format = THREE.RedFormat;
  75. texture.minFilter = THREE.LinearFilter;
  76. texture.magFilter = THREE.LinearFilter;
  77. texture.unpackAlignment = 1;
  78. texture.needsUpdate = true;
  79. // Material
  80. const vertexShader = /* glsl */`
  81. in vec3 position;
  82. uniform mat4 modelMatrix;
  83. uniform mat4 modelViewMatrix;
  84. uniform mat4 projectionMatrix;
  85. uniform vec3 cameraPos;
  86. out vec3 vOrigin;
  87. out vec3 vDirection;
  88. void main() {
  89. vec4 mvPosition = modelViewMatrix * vec4( position, 1.0 );
  90. vOrigin = vec3( inverse( modelMatrix ) * vec4( cameraPos, 1.0 ) ).xyz;
  91. vDirection = position - vOrigin;
  92. gl_Position = projectionMatrix * mvPosition;
  93. }
  94. `;
  95. const fragmentShader = /* glsl */`
  96. precision highp float;
  97. precision highp sampler3D;
  98. uniform mat4 modelViewMatrix;
  99. uniform mat4 projectionMatrix;
  100. in vec3 vOrigin;
  101. in vec3 vDirection;
  102. out vec4 color;
  103. uniform vec3 base;
  104. uniform sampler3D map;
  105. uniform float threshold;
  106. uniform float range;
  107. uniform float opacity;
  108. uniform float steps;
  109. uniform float frame;
  110. uint wang_hash(uint seed)
  111. {
  112. seed = (seed ^ 61u) ^ (seed >> 16u);
  113. seed *= 9u;
  114. seed = seed ^ (seed >> 4u);
  115. seed *= 0x27d4eb2du;
  116. seed = seed ^ (seed >> 15u);
  117. return seed;
  118. }
  119. float randomFloat(inout uint seed)
  120. {
  121. return float(wang_hash(seed)) / 4294967296.;
  122. }
  123. vec2 hitBox( vec3 orig, vec3 dir ) {
  124. const vec3 box_min = vec3( - 0.5 );
  125. const vec3 box_max = vec3( 0.5 );
  126. vec3 inv_dir = 1.0 / dir;
  127. vec3 tmin_tmp = ( box_min - orig ) * inv_dir;
  128. vec3 tmax_tmp = ( box_max - orig ) * inv_dir;
  129. vec3 tmin = min( tmin_tmp, tmax_tmp );
  130. vec3 tmax = max( tmin_tmp, tmax_tmp );
  131. float t0 = max( tmin.x, max( tmin.y, tmin.z ) );
  132. float t1 = min( tmax.x, min( tmax.y, tmax.z ) );
  133. return vec2( t0, t1 );
  134. }
  135. float sample1( vec3 p ) {
  136. return texture( map, p ).r;
  137. }
  138. float shading( vec3 coord ) {
  139. float step = 0.01;
  140. return sample1( coord + vec3( - step ) ) - sample1( coord + vec3( step ) );
  141. }
  142. vec4 linearToSRGB( in vec4 value ) {
  143. return vec4( mix( pow( value.rgb, vec3( 0.41666 ) ) * 1.055 - vec3( 0.055 ), value.rgb * 12.92, vec3( lessThanEqual( value.rgb, vec3( 0.0031308 ) ) ) ), value.a );
  144. }
  145. void main(){
  146. vec3 rayDir = normalize( vDirection );
  147. vec2 bounds = hitBox( vOrigin, rayDir );
  148. if ( bounds.x > bounds.y ) discard;
  149. bounds.x = max( bounds.x, 0.0 );
  150. vec3 p = vOrigin + bounds.x * rayDir;
  151. vec3 inc = 1.0 / abs( rayDir );
  152. float delta = min( inc.x, min( inc.y, inc.z ) );
  153. delta /= steps;
  154. // Jitter
  155. // Nice little seed from
  156. // https://blog.demofox.org/2020/05/25/casual-shadertoy-path-tracing-1-basic-camera-diffuse-emissive/
  157. uint seed = uint( gl_FragCoord.x ) * uint( 1973 ) + uint( gl_FragCoord.y ) * uint( 9277 ) + uint( frame ) * uint( 26699 );
  158. vec3 size = vec3( textureSize( map, 0 ) );
  159. float randNum = randomFloat( seed ) * 2.0 - 1.0;
  160. p += rayDir * randNum * ( 1.0 / size );
  161. //
  162. vec4 ac = vec4( base, 0.0 );
  163. for ( float t = bounds.x; t < bounds.y; t += delta ) {
  164. float d = sample1( p + 0.5 );
  165. d = smoothstep( threshold - range, threshold + range, d ) * opacity;
  166. float col = shading( p + 0.5 ) * 3.0 + ( ( p.x + p.y ) * 0.25 ) + 0.2;
  167. ac.rgb += ( 1.0 - ac.a ) * d * col;
  168. ac.a += ( 1.0 - ac.a ) * d;
  169. if ( ac.a >= 0.95 ) break;
  170. p += rayDir * delta;
  171. }
  172. color = linearToSRGB( ac );
  173. if ( color.a == 0.0 ) discard;
  174. }
  175. `;
  176. const geometry = new THREE.BoxGeometry( 1, 1, 1 );
  177. const material = new THREE.RawShaderMaterial( {
  178. glslVersion: THREE.GLSL3,
  179. uniforms: {
  180. base: { value: new THREE.Color( 0x798aa0 ) },
  181. map: { value: texture },
  182. cameraPos: { value: new THREE.Vector3() },
  183. threshold: { value: 0.25 },
  184. opacity: { value: 0.25 },
  185. range: { value: 0.1 },
  186. steps: { value: 100 },
  187. frame: { value: 0 }
  188. },
  189. vertexShader,
  190. fragmentShader,
  191. side: THREE.BackSide,
  192. transparent: true
  193. } );
  194. mesh = new THREE.Mesh( geometry, material );
  195. scene.add( mesh );
  196. //
  197. const parameters = {
  198. threshold: 0.25,
  199. opacity: 0.25,
  200. range: 0.1,
  201. steps: 100
  202. };
  203. function update() {
  204. material.uniforms.threshold.value = parameters.threshold;
  205. material.uniforms.opacity.value = parameters.opacity;
  206. material.uniforms.range.value = parameters.range;
  207. material.uniforms.steps.value = parameters.steps;
  208. }
  209. const gui = new GUI();
  210. gui.add( parameters, 'threshold', 0, 1, 0.01 ).onChange( update );
  211. gui.add( parameters, 'opacity', 0, 1, 0.01 ).onChange( update );
  212. gui.add( parameters, 'range', 0, 1, 0.01 ).onChange( update );
  213. gui.add( parameters, 'steps', 0, 200, 1 ).onChange( update );
  214. window.addEventListener( 'resize', onWindowResize );
  215. }
  216. function onWindowResize() {
  217. camera.aspect = window.innerWidth / window.innerHeight;
  218. camera.updateProjectionMatrix();
  219. renderer.setSize( window.innerWidth, window.innerHeight );
  220. }
  221. function animate() {
  222. mesh.material.uniforms.cameraPos.value.copy( camera.position );
  223. mesh.rotation.y = - performance.now() / 7500;
  224. mesh.material.uniforms.frame.value ++;
  225. renderer.render( scene, camera );
  226. }
  227. </script>
  228. </body>
  229. </html>