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webgl2_volume_cloud.html 8.3 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. <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. import WebGL from 'three/addons/capabilities/WebGL.js';
  27. if ( WebGL.isWebGL2Available() === false ) {
  28. document.body.appendChild( WebGL.getWebGL2ErrorMessage() );
  29. }
  30. let renderer, scene, camera;
  31. let mesh;
  32. init();
  33. animate();
  34. function init() {
  35. renderer = new THREE.WebGLRenderer();
  36. renderer.setPixelRatio( window.devicePixelRatio );
  37. renderer.setSize( window.innerWidth, window.innerHeight );
  38. document.body.appendChild( renderer.domElement );
  39. scene = new THREE.Scene();
  40. camera = new THREE.PerspectiveCamera( 60, window.innerWidth / window.innerHeight, 0.1, 100 );
  41. camera.position.set( 0, 0, 1.5 );
  42. new OrbitControls( camera, renderer.domElement );
  43. // Sky
  44. const canvas = document.createElement( 'canvas' );
  45. canvas.width = 1;
  46. canvas.height = 32;
  47. const context = canvas.getContext( '2d' );
  48. const gradient = context.createLinearGradient( 0, 0, 0, 32 );
  49. gradient.addColorStop( 0.0, '#014a84' );
  50. gradient.addColorStop( 0.5, '#0561a0' );
  51. gradient.addColorStop( 1.0, '#437ab6' );
  52. context.fillStyle = gradient;
  53. context.fillRect( 0, 0, 1, 32 );
  54. const skyMap = new THREE.CanvasTexture( canvas );
  55. skyMap.colorSpace = THREE.SRGBColorSpace;
  56. const sky = new THREE.Mesh(
  57. new THREE.SphereGeometry( 10 ),
  58. new THREE.MeshBasicMaterial( { map: skyMap, side: THREE.BackSide } )
  59. );
  60. scene.add( sky );
  61. // Texture
  62. const size = 128;
  63. const data = new Uint8Array( size * size * size );
  64. let i = 0;
  65. const scale = 0.05;
  66. const perlin = new ImprovedNoise();
  67. const vector = new THREE.Vector3();
  68. for ( let z = 0; z < size; z ++ ) {
  69. for ( let y = 0; y < size; y ++ ) {
  70. for ( let x = 0; x < size; x ++ ) {
  71. const d = 1.0 - vector.set( x, y, z ).subScalar( size / 2 ).divideScalar( size ).length();
  72. data[ i ] = ( 128 + 128 * perlin.noise( x * scale / 1.5, y * scale, z * scale / 1.5 ) ) * d * d;
  73. i ++;
  74. }
  75. }
  76. }
  77. const texture = new THREE.Data3DTexture( data, size, size, size );
  78. texture.format = THREE.RedFormat;
  79. texture.minFilter = THREE.LinearFilter;
  80. texture.magFilter = THREE.LinearFilter;
  81. texture.unpackAlignment = 1;
  82. texture.needsUpdate = true;
  83. // Material
  84. const vertexShader = /* glsl */`
  85. in vec3 position;
  86. uniform mat4 modelMatrix;
  87. uniform mat4 modelViewMatrix;
  88. uniform mat4 projectionMatrix;
  89. uniform vec3 cameraPos;
  90. out vec3 vOrigin;
  91. out vec3 vDirection;
  92. void main() {
  93. vec4 mvPosition = modelViewMatrix * vec4( position, 1.0 );
  94. vOrigin = vec3( inverse( modelMatrix ) * vec4( cameraPos, 1.0 ) ).xyz;
  95. vDirection = position - vOrigin;
  96. gl_Position = projectionMatrix * mvPosition;
  97. }
  98. `;
  99. const fragmentShader = /* glsl */`
  100. precision highp float;
  101. precision highp sampler3D;
  102. uniform mat4 modelViewMatrix;
  103. uniform mat4 projectionMatrix;
  104. in vec3 vOrigin;
  105. in vec3 vDirection;
  106. out vec4 color;
  107. uniform vec3 base;
  108. uniform sampler3D map;
  109. uniform float threshold;
  110. uniform float range;
  111. uniform float opacity;
  112. uniform float steps;
  113. uniform float frame;
  114. uint wang_hash(uint seed)
  115. {
  116. seed = (seed ^ 61u) ^ (seed >> 16u);
  117. seed *= 9u;
  118. seed = seed ^ (seed >> 4u);
  119. seed *= 0x27d4eb2du;
  120. seed = seed ^ (seed >> 15u);
  121. return seed;
  122. }
  123. float randomFloat(inout uint seed)
  124. {
  125. return float(wang_hash(seed)) / 4294967296.;
  126. }
  127. vec2 hitBox( vec3 orig, vec3 dir ) {
  128. const vec3 box_min = vec3( - 0.5 );
  129. const vec3 box_max = vec3( 0.5 );
  130. vec3 inv_dir = 1.0 / dir;
  131. vec3 tmin_tmp = ( box_min - orig ) * inv_dir;
  132. vec3 tmax_tmp = ( box_max - orig ) * inv_dir;
  133. vec3 tmin = min( tmin_tmp, tmax_tmp );
  134. vec3 tmax = max( tmin_tmp, tmax_tmp );
  135. float t0 = max( tmin.x, max( tmin.y, tmin.z ) );
  136. float t1 = min( tmax.x, min( tmax.y, tmax.z ) );
  137. return vec2( t0, t1 );
  138. }
  139. float sample1( vec3 p ) {
  140. return texture( map, p ).r;
  141. }
  142. float shading( vec3 coord ) {
  143. float step = 0.01;
  144. return sample1( coord + vec3( - step ) ) - sample1( coord + vec3( step ) );
  145. }
  146. vec4 linearToSRGB( in vec4 value ) {
  147. 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 );
  148. }
  149. void main(){
  150. vec3 rayDir = normalize( vDirection );
  151. vec2 bounds = hitBox( vOrigin, rayDir );
  152. if ( bounds.x > bounds.y ) discard;
  153. bounds.x = max( bounds.x, 0.0 );
  154. vec3 p = vOrigin + bounds.x * rayDir;
  155. vec3 inc = 1.0 / abs( rayDir );
  156. float delta = min( inc.x, min( inc.y, inc.z ) );
  157. delta /= steps;
  158. // Jitter
  159. // Nice little seed from
  160. // https://blog.demofox.org/2020/05/25/casual-shadertoy-path-tracing-1-basic-camera-diffuse-emissive/
  161. uint seed = uint( gl_FragCoord.x ) * uint( 1973 ) + uint( gl_FragCoord.y ) * uint( 9277 ) + uint( frame ) * uint( 26699 );
  162. vec3 size = vec3( textureSize( map, 0 ) );
  163. float randNum = randomFloat( seed ) * 2.0 - 1.0;
  164. p += rayDir * randNum * ( 1.0 / size );
  165. //
  166. vec4 ac = vec4( base, 0.0 );
  167. for ( float t = bounds.x; t < bounds.y; t += delta ) {
  168. float d = sample1( p + 0.5 );
  169. d = smoothstep( threshold - range, threshold + range, d ) * opacity;
  170. float col = shading( p + 0.5 ) * 3.0 + ( ( p.x + p.y ) * 0.25 ) + 0.2;
  171. ac.rgb += ( 1.0 - ac.a ) * d * col;
  172. ac.a += ( 1.0 - ac.a ) * d;
  173. if ( ac.a >= 0.95 ) break;
  174. p += rayDir * delta;
  175. }
  176. color = linearToSRGB( ac );
  177. if ( color.a == 0.0 ) discard;
  178. }
  179. `;
  180. const geometry = new THREE.BoxGeometry( 1, 1, 1 );
  181. const material = new THREE.RawShaderMaterial( {
  182. glslVersion: THREE.GLSL3,
  183. uniforms: {
  184. base: { value: new THREE.Color( 0x798aa0 ) },
  185. map: { value: texture },
  186. cameraPos: { value: new THREE.Vector3() },
  187. threshold: { value: 0.25 },
  188. opacity: { value: 0.25 },
  189. range: { value: 0.1 },
  190. steps: { value: 100 },
  191. frame: { value: 0 }
  192. },
  193. vertexShader,
  194. fragmentShader,
  195. side: THREE.BackSide,
  196. transparent: true
  197. } );
  198. mesh = new THREE.Mesh( geometry, material );
  199. scene.add( mesh );
  200. //
  201. const parameters = {
  202. threshold: 0.25,
  203. opacity: 0.25,
  204. range: 0.1,
  205. steps: 100
  206. };
  207. function update() {
  208. material.uniforms.threshold.value = parameters.threshold;
  209. material.uniforms.opacity.value = parameters.opacity;
  210. material.uniforms.range.value = parameters.range;
  211. material.uniforms.steps.value = parameters.steps;
  212. }
  213. const gui = new GUI();
  214. gui.add( parameters, 'threshold', 0, 1, 0.01 ).onChange( update );
  215. gui.add( parameters, 'opacity', 0, 1, 0.01 ).onChange( update );
  216. gui.add( parameters, 'range', 0, 1, 0.01 ).onChange( update );
  217. gui.add( parameters, 'steps', 0, 200, 1 ).onChange( update );
  218. window.addEventListener( 'resize', onWindowResize );
  219. }
  220. function onWindowResize() {
  221. camera.aspect = window.innerWidth / window.innerHeight;
  222. camera.updateProjectionMatrix();
  223. renderer.setSize( window.innerWidth, window.innerHeight );
  224. }
  225. function animate() {
  226. requestAnimationFrame( animate );
  227. mesh.material.uniforms.cameraPos.value.copy( camera.position );
  228. mesh.rotation.y = - performance.now() / 7500;
  229. mesh.material.uniforms.frame.value ++;
  230. renderer.render( scene, camera );
  231. }
  232. </script>
  233. </body>
  234. </html>