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webgl2_volume_cloud.html 7.9 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="module">
  14. import * as THREE from '../build/three.module.js';
  15. import { OrbitControls } from './jsm/controls/OrbitControls.js';
  16. import { ImprovedNoise } from './jsm/math/ImprovedNoise.js';
  17. import { GUI } from './jsm/libs/lil-gui.module.min.js';
  18. import { WEBGL } from './jsm/WebGL.js';
  19. if ( WEBGL.isWebGL2Available() === false ) {
  20. document.body.appendChild( WEBGL.getWebGL2ErrorMessage() );
  21. }
  22. let renderer, scene, camera;
  23. let mesh;
  24. init();
  25. animate();
  26. function init() {
  27. renderer = new THREE.WebGLRenderer();
  28. renderer.setPixelRatio( window.devicePixelRatio );
  29. renderer.setSize( window.innerWidth, window.innerHeight );
  30. document.body.appendChild( renderer.domElement );
  31. scene = new THREE.Scene();
  32. camera = new THREE.PerspectiveCamera( 60, window.innerWidth / window.innerHeight, 0.1, 100 );
  33. camera.position.set( 0, 0, 1.5 );
  34. new OrbitControls( camera, renderer.domElement );
  35. // Sky
  36. const canvas = document.createElement( 'canvas' );
  37. canvas.width = 1;
  38. canvas.height = 32;
  39. const context = canvas.getContext( '2d' );
  40. const gradient = context.createLinearGradient( 0, 0, 0, 32 );
  41. gradient.addColorStop( 0.0, '#014a84' );
  42. gradient.addColorStop( 0.5, '#0561a0' );
  43. gradient.addColorStop( 1.0, '#437ab6' );
  44. context.fillStyle = gradient;
  45. context.fillRect( 0, 0, 1, 32 );
  46. const sky = new THREE.Mesh(
  47. new THREE.SphereGeometry( 10 ),
  48. new THREE.MeshBasicMaterial( { map: new THREE.CanvasTexture( canvas ), side: THREE.BackSide } )
  49. );
  50. scene.add( sky );
  51. // Texture
  52. const size = 128;
  53. const data = new Uint8Array( size * size * size );
  54. let i = 0;
  55. const scale = 0.05;
  56. const perlin = new ImprovedNoise();
  57. const vector = new THREE.Vector3();
  58. for ( let z = 0; z < size; z ++ ) {
  59. for ( let y = 0; y < size; y ++ ) {
  60. for ( let x = 0; x < size; x ++ ) {
  61. const d = 1.0 - vector.set( x, y, z ).subScalar( size / 2 ).divideScalar( size ).length();
  62. data[ i ] = ( 128 + 128 * perlin.noise( x * scale / 1.5, y * scale, z * scale / 1.5 ) ) * d * d;
  63. i ++;
  64. }
  65. }
  66. }
  67. const texture = new THREE.DataTexture3D( data, size, size, size );
  68. texture.format = THREE.RedFormat;
  69. texture.minFilter = THREE.LinearFilter;
  70. texture.magFilter = THREE.LinearFilter;
  71. texture.unpackAlignment = 1;
  72. texture.needsUpdate = true;
  73. // Material
  74. const vertexShader = /* glsl */`
  75. in vec3 position;
  76. uniform mat4 modelMatrix;
  77. uniform mat4 modelViewMatrix;
  78. uniform mat4 projectionMatrix;
  79. uniform vec3 cameraPos;
  80. out vec3 vOrigin;
  81. out vec3 vDirection;
  82. void main() {
  83. vec4 mvPosition = modelViewMatrix * vec4( position, 1.0 );
  84. vOrigin = vec3( inverse( modelMatrix ) * vec4( cameraPos, 1.0 ) ).xyz;
  85. vDirection = position - vOrigin;
  86. gl_Position = projectionMatrix * mvPosition;
  87. }
  88. `;
  89. const fragmentShader = /* glsl */`
  90. precision highp float;
  91. precision highp sampler3D;
  92. uniform mat4 modelViewMatrix;
  93. uniform mat4 projectionMatrix;
  94. in vec3 vOrigin;
  95. in vec3 vDirection;
  96. out vec4 color;
  97. uniform vec3 base;
  98. uniform sampler3D map;
  99. uniform float threshold;
  100. uniform float range;
  101. uniform float opacity;
  102. uniform float steps;
  103. uniform float frame;
  104. uint wang_hash(uint seed)
  105. {
  106. seed = (seed ^ 61u) ^ (seed >> 16u);
  107. seed *= 9u;
  108. seed = seed ^ (seed >> 4u);
  109. seed *= 0x27d4eb2du;
  110. seed = seed ^ (seed >> 15u);
  111. return seed;
  112. }
  113. float randomFloat(inout uint seed)
  114. {
  115. return float(wang_hash(seed)) / 4294967296.;
  116. }
  117. vec2 hitBox( vec3 orig, vec3 dir ) {
  118. const vec3 box_min = vec3( - 0.5 );
  119. const vec3 box_max = vec3( 0.5 );
  120. vec3 inv_dir = 1.0 / dir;
  121. vec3 tmin_tmp = ( box_min - orig ) * inv_dir;
  122. vec3 tmax_tmp = ( box_max - orig ) * inv_dir;
  123. vec3 tmin = min( tmin_tmp, tmax_tmp );
  124. vec3 tmax = max( tmin_tmp, tmax_tmp );
  125. float t0 = max( tmin.x, max( tmin.y, tmin.z ) );
  126. float t1 = min( tmax.x, min( tmax.y, tmax.z ) );
  127. return vec2( t0, t1 );
  128. }
  129. float sample1( vec3 p ) {
  130. return texture( map, p ).r;
  131. }
  132. float shading( vec3 coord ) {
  133. float step = 0.01;
  134. return sample1( coord + vec3( - step ) ) - sample1( coord + vec3( step ) );
  135. }
  136. void main(){
  137. vec3 rayDir = normalize( vDirection );
  138. vec2 bounds = hitBox( vOrigin, rayDir );
  139. if ( bounds.x > bounds.y ) discard;
  140. bounds.x = max( bounds.x, 0.0 );
  141. vec3 p = vOrigin + bounds.x * rayDir;
  142. vec3 inc = 1.0 / abs( rayDir );
  143. float delta = min( inc.x, min( inc.y, inc.z ) );
  144. delta /= steps;
  145. // Jitter
  146. // Nice little seed from
  147. // https://blog.demofox.org/2020/05/25/casual-shadertoy-path-tracing-1-basic-camera-diffuse-emissive/
  148. uint seed = uint( gl_FragCoord.x ) * uint( 1973 ) + uint( gl_FragCoord.y ) * uint( 9277 ) + uint( frame ) * uint( 26699 );
  149. vec3 size = vec3( textureSize( map, 0 ) );
  150. float randNum = randomFloat( seed ) * 2.0 - 1.0;
  151. p += rayDir * randNum * ( 1.0 / size );
  152. //
  153. vec4 ac = vec4( base, 0.0 );
  154. for ( float t = bounds.x; t < bounds.y; t += delta ) {
  155. float d = sample1( p + 0.5 );
  156. d = smoothstep( threshold - range, threshold + range, d ) * opacity;
  157. float col = shading( p + 0.5 ) * 3.0 + ( ( p.x + p.y ) * 0.25 ) + 0.2;
  158. ac.rgb += ( 1.0 - ac.a ) * d * col;
  159. ac.a += ( 1.0 - ac.a ) * d;
  160. if ( ac.a >= 0.95 ) break;
  161. p += rayDir * delta;
  162. }
  163. color = ac;
  164. if ( color.a == 0.0 ) discard;
  165. }
  166. `;
  167. const geometry = new THREE.BoxGeometry( 1, 1, 1 );
  168. const material = new THREE.RawShaderMaterial( {
  169. glslVersion: THREE.GLSL3,
  170. uniforms: {
  171. base: { value: new THREE.Color( 0x798aa0 ) },
  172. map: { value: texture },
  173. cameraPos: { value: new THREE.Vector3() },
  174. threshold: { value: 0.25 },
  175. opacity: { value: 0.25 },
  176. range: { value: 0.1 },
  177. steps: { value: 100 },
  178. frame: { value: 0 }
  179. },
  180. vertexShader,
  181. fragmentShader,
  182. side: THREE.BackSide,
  183. transparent: true
  184. } );
  185. mesh = new THREE.Mesh( geometry, material );
  186. scene.add( mesh );
  187. //
  188. const parameters = {
  189. threshold: 0.25,
  190. opacity: 0.25,
  191. range: 0.1,
  192. steps: 100
  193. };
  194. function update() {
  195. material.uniforms.threshold.value = parameters.threshold;
  196. material.uniforms.opacity.value = parameters.opacity;
  197. material.uniforms.range.value = parameters.range;
  198. material.uniforms.steps.value = parameters.steps;
  199. }
  200. const gui = new GUI();
  201. gui.add( parameters, 'threshold', 0, 1, 0.01 ).onChange( update );
  202. gui.add( parameters, 'opacity', 0, 1, 0.01 ).onChange( update );
  203. gui.add( parameters, 'range', 0, 1, 0.01 ).onChange( update );
  204. gui.add( parameters, 'steps', 0, 200, 1 ).onChange( update );
  205. window.addEventListener( 'resize', onWindowResize );
  206. }
  207. function onWindowResize() {
  208. camera.aspect = window.innerWidth / window.innerHeight;
  209. camera.updateProjectionMatrix();
  210. renderer.setSize( window.innerWidth, window.innerHeight );
  211. }
  212. function animate() {
  213. requestAnimationFrame( animate );
  214. mesh.material.uniforms.cameraPos.value.copy( camera.position );
  215. mesh.rotation.y = - performance.now() / 7500;
  216. mesh.material.uniforms.frame.value ++;
  217. renderer.render( scene, camera );
  218. }
  219. </script>
  220. </body>
  221. </html>