webgl_gpgpu_protoplanet.html 14 KB

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  1. <!DOCTYPE html>
  2. <html lang="en">
  3. <head>
  4. <title>three.js webgl - gpgpu - protoplanet</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> - <span id="protoplanets"></span> webgl gpgpu debris
  12. </div>
  13. <!-- Fragment shader for protoplanet's position -->
  14. <script id="computeShaderPosition" type="x-shader/x-fragment">
  15. #define delta ( 1.0 / 60.0 )
  16. void main() {
  17. vec2 uv = gl_FragCoord.xy / resolution.xy;
  18. vec4 tmpPos = texture2D( texturePosition, uv );
  19. vec3 pos = tmpPos.xyz;
  20. vec4 tmpVel = texture2D( textureVelocity, uv );
  21. vec3 vel = tmpVel.xyz;
  22. float mass = tmpVel.w;
  23. if ( mass == 0.0 ) {
  24. vel = vec3( 0.0 );
  25. }
  26. // Dynamics
  27. pos += vel * delta;
  28. gl_FragColor = vec4( pos, 1.0 );
  29. }
  30. </script>
  31. <!-- Fragment shader for protoplanet's velocity -->
  32. <script id="computeShaderVelocity" type="x-shader/x-fragment">
  33. // For PI declaration:
  34. #include <common>
  35. #define delta ( 1.0 / 60.0 )
  36. uniform float gravityConstant;
  37. uniform float density;
  38. const float width = resolution.x;
  39. const float height = resolution.y;
  40. float radiusFromMass( float mass ) {
  41. // Calculate radius of a sphere from mass and density
  42. return pow( ( 3.0 / ( 4.0 * PI ) ) * mass / density, 1.0 / 3.0 );
  43. }
  44. void main() {
  45. vec2 uv = gl_FragCoord.xy / resolution.xy;
  46. float idParticle = uv.y * resolution.x + uv.x;
  47. vec4 tmpPos = texture2D( texturePosition, uv );
  48. vec3 pos = tmpPos.xyz;
  49. vec4 tmpVel = texture2D( textureVelocity, uv );
  50. vec3 vel = tmpVel.xyz;
  51. float mass = tmpVel.w;
  52. if ( mass > 0.0 ) {
  53. float radius = radiusFromMass( mass );
  54. vec3 acceleration = vec3( 0.0 );
  55. // Gravity interaction
  56. for ( float y = 0.0; y < height; y++ ) {
  57. for ( float x = 0.0; x < width; x++ ) {
  58. vec2 secondParticleCoords = vec2( x + 0.5, y + 0.5 ) / resolution.xy;
  59. vec3 pos2 = texture2D( texturePosition, secondParticleCoords ).xyz;
  60. vec4 velTemp2 = texture2D( textureVelocity, secondParticleCoords );
  61. vec3 vel2 = velTemp2.xyz;
  62. float mass2 = velTemp2.w;
  63. float idParticle2 = secondParticleCoords.y * resolution.x + secondParticleCoords.x;
  64. if ( idParticle == idParticle2 ) {
  65. continue;
  66. }
  67. if ( mass2 == 0.0 ) {
  68. continue;
  69. }
  70. vec3 dPos = pos2 - pos;
  71. float distance = length( dPos );
  72. float radius2 = radiusFromMass( mass2 );
  73. if ( distance == 0.0 ) {
  74. continue;
  75. }
  76. // Checks collision
  77. if ( distance < radius + radius2 ) {
  78. if ( idParticle < idParticle2 ) {
  79. // This particle is aggregated by the other
  80. vel = ( vel * mass + vel2 * mass2 ) / ( mass + mass2 );
  81. mass += mass2;
  82. radius = radiusFromMass( mass );
  83. }
  84. else {
  85. // This particle dies
  86. mass = 0.0;
  87. radius = 0.0;
  88. vel = vec3( 0.0 );
  89. break;
  90. }
  91. }
  92. float distanceSq = distance * distance;
  93. float gravityField = gravityConstant * mass2 / distanceSq;
  94. gravityField = min( gravityField, 1000.0 );
  95. acceleration += gravityField * normalize( dPos );
  96. }
  97. if ( mass == 0.0 ) {
  98. break;
  99. }
  100. }
  101. // Dynamics
  102. vel += delta * acceleration;
  103. }
  104. gl_FragColor = vec4( vel, mass );
  105. }
  106. </script>
  107. <!-- Particles vertex shader -->
  108. <script type="x-shader/x-vertex" id="particleVertexShader">
  109. // For PI declaration:
  110. #include <common>
  111. uniform sampler2D texturePosition;
  112. uniform sampler2D textureVelocity;
  113. uniform float cameraConstant;
  114. uniform float density;
  115. varying vec4 vColor;
  116. float radiusFromMass( float mass ) {
  117. // Calculate radius of a sphere from mass and density
  118. return pow( ( 3.0 / ( 4.0 * PI ) ) * mass / density, 1.0 / 3.0 );
  119. }
  120. void main() {
  121. vec4 posTemp = texture2D( texturePosition, uv );
  122. vec3 pos = posTemp.xyz;
  123. vec4 velTemp = texture2D( textureVelocity, uv );
  124. vec3 vel = velTemp.xyz;
  125. float mass = velTemp.w;
  126. vColor = vec4( 1.0, mass / 250.0, 0.0, 1.0 );
  127. vec4 mvPosition = modelViewMatrix * vec4( pos, 1.0 );
  128. // Calculate radius of a sphere from mass and density
  129. //float radius = pow( ( 3.0 / ( 4.0 * PI ) ) * mass / density, 1.0 / 3.0 );
  130. float radius = radiusFromMass( mass );
  131. // Apparent size in pixels
  132. if ( mass == 0.0 ) {
  133. gl_PointSize = 0.0;
  134. }
  135. else {
  136. gl_PointSize = radius * cameraConstant / ( - mvPosition.z );
  137. }
  138. gl_Position = projectionMatrix * mvPosition;
  139. }
  140. </script>
  141. <!-- Particles fragment shader -->
  142. <script type="x-shader/x-fragment" id="particleFragmentShader">
  143. varying vec4 vColor;
  144. void main() {
  145. if ( vColor.y == 0.0 ) discard;
  146. float f = length( gl_PointCoord - vec2( 0.5, 0.5 ) );
  147. if ( f > 0.5 ) {
  148. discard;
  149. }
  150. gl_FragColor = vColor;
  151. }
  152. </script>
  153. <script type="importmap">
  154. {
  155. "imports": {
  156. "three": "../build/three.module.js",
  157. "three/addons/": "./jsm/"
  158. }
  159. }
  160. </script>
  161. <script type="module">
  162. import * as THREE from 'three';
  163. import Stats from 'three/addons/libs/stats.module.js';
  164. import { GUI } from 'three/addons/libs/lil-gui.module.min.js';
  165. import { OrbitControls } from 'three/addons/controls/OrbitControls.js';
  166. import { GPUComputationRenderer } from 'three/addons/misc/GPUComputationRenderer.js';
  167. // Texture width for simulation (each texel is a debris particle)
  168. const WIDTH = 64;
  169. let container, stats;
  170. let camera, scene, renderer, geometry;
  171. const PARTICLES = WIDTH * WIDTH;
  172. let gpuCompute;
  173. let velocityVariable;
  174. let positionVariable;
  175. let velocityUniforms;
  176. let particleUniforms;
  177. let effectController;
  178. init();
  179. function init() {
  180. container = document.createElement( 'div' );
  181. document.body.appendChild( container );
  182. camera = new THREE.PerspectiveCamera( 75, window.innerWidth / window.innerHeight, 5, 15000 );
  183. camera.position.y = 120;
  184. camera.position.z = 400;
  185. scene = new THREE.Scene();
  186. renderer = new THREE.WebGLRenderer();
  187. renderer.setPixelRatio( window.devicePixelRatio );
  188. renderer.setSize( window.innerWidth, window.innerHeight );
  189. renderer.setAnimationLoop( animate );
  190. container.appendChild( renderer.domElement );
  191. const controls = new OrbitControls( camera, renderer.domElement );
  192. controls.minDistance = 100;
  193. controls.maxDistance = 1000;
  194. effectController = {
  195. // Can be changed dynamically
  196. gravityConstant: 100.0,
  197. density: 0.45,
  198. // Must restart simulation
  199. radius: 300,
  200. height: 8,
  201. exponent: 0.4,
  202. maxMass: 15.0,
  203. velocity: 70,
  204. velocityExponent: 0.2,
  205. randVelocity: 0.001
  206. };
  207. initComputeRenderer();
  208. stats = new Stats();
  209. container.appendChild( stats.dom );
  210. window.addEventListener( 'resize', onWindowResize );
  211. initGUI();
  212. initProtoplanets();
  213. dynamicValuesChanger();
  214. }
  215. function initComputeRenderer() {
  216. gpuCompute = new GPUComputationRenderer( WIDTH, WIDTH, renderer );
  217. const dtPosition = gpuCompute.createTexture();
  218. const dtVelocity = gpuCompute.createTexture();
  219. fillTextures( dtPosition, dtVelocity );
  220. velocityVariable = gpuCompute.addVariable( 'textureVelocity', document.getElementById( 'computeShaderVelocity' ).textContent, dtVelocity );
  221. positionVariable = gpuCompute.addVariable( 'texturePosition', document.getElementById( 'computeShaderPosition' ).textContent, dtPosition );
  222. gpuCompute.setVariableDependencies( velocityVariable, [ positionVariable, velocityVariable ] );
  223. gpuCompute.setVariableDependencies( positionVariable, [ positionVariable, velocityVariable ] );
  224. velocityUniforms = velocityVariable.material.uniforms;
  225. velocityUniforms[ 'gravityConstant' ] = { value: 0.0 };
  226. velocityUniforms[ 'density' ] = { value: 0.0 };
  227. const error = gpuCompute.init();
  228. if ( error !== null ) {
  229. console.error( error );
  230. }
  231. }
  232. function restartSimulation() {
  233. const dtPosition = gpuCompute.createTexture();
  234. const dtVelocity = gpuCompute.createTexture();
  235. fillTextures( dtPosition, dtVelocity );
  236. gpuCompute.renderTexture( dtPosition, positionVariable.renderTargets[ 0 ] );
  237. gpuCompute.renderTexture( dtPosition, positionVariable.renderTargets[ 1 ] );
  238. gpuCompute.renderTexture( dtVelocity, velocityVariable.renderTargets[ 0 ] );
  239. gpuCompute.renderTexture( dtVelocity, velocityVariable.renderTargets[ 1 ] );
  240. }
  241. function initProtoplanets() {
  242. geometry = new THREE.BufferGeometry();
  243. const positions = new Float32Array( PARTICLES * 3 );
  244. let p = 0;
  245. for ( let i = 0; i < PARTICLES; i ++ ) {
  246. positions[ p ++ ] = ( Math.random() * 2 - 1 ) * effectController.radius;
  247. positions[ p ++ ] = 0; //( Math.random() * 2 - 1 ) * effectController.radius;
  248. positions[ p ++ ] = ( Math.random() * 2 - 1 ) * effectController.radius;
  249. }
  250. const uvs = new Float32Array( PARTICLES * 2 );
  251. p = 0;
  252. for ( let j = 0; j < WIDTH; j ++ ) {
  253. for ( let i = 0; i < WIDTH; i ++ ) {
  254. uvs[ p ++ ] = i / ( WIDTH - 1 );
  255. uvs[ p ++ ] = j / ( WIDTH - 1 );
  256. }
  257. }
  258. geometry.setAttribute( 'position', new THREE.BufferAttribute( positions, 3 ) );
  259. geometry.setAttribute( 'uv', new THREE.BufferAttribute( uvs, 2 ) );
  260. particleUniforms = {
  261. 'texturePosition': { value: null },
  262. 'textureVelocity': { value: null },
  263. 'cameraConstant': { value: getCameraConstant( camera ) },
  264. 'density': { value: 0.0 }
  265. };
  266. // THREE.ShaderMaterial
  267. const material = new THREE.ShaderMaterial( {
  268. uniforms: particleUniforms,
  269. vertexShader: document.getElementById( 'particleVertexShader' ).textContent,
  270. fragmentShader: document.getElementById( 'particleFragmentShader' ).textContent
  271. } );
  272. const particles = new THREE.Points( geometry, material );
  273. particles.matrixAutoUpdate = false;
  274. particles.updateMatrix();
  275. scene.add( particles );
  276. }
  277. function fillTextures( texturePosition, textureVelocity ) {
  278. const posArray = texturePosition.image.data;
  279. const velArray = textureVelocity.image.data;
  280. const radius = effectController.radius;
  281. const height = effectController.height;
  282. const exponent = effectController.exponent;
  283. const maxMass = effectController.maxMass * 1024 / PARTICLES;
  284. const maxVel = effectController.velocity;
  285. const velExponent = effectController.velocityExponent;
  286. const randVel = effectController.randVelocity;
  287. for ( let k = 0, kl = posArray.length; k < kl; k += 4 ) {
  288. // Position
  289. let x, z, rr;
  290. do {
  291. x = ( Math.random() * 2 - 1 );
  292. z = ( Math.random() * 2 - 1 );
  293. rr = x * x + z * z;
  294. } while ( rr > 1 );
  295. rr = Math.sqrt( rr );
  296. const rExp = radius * Math.pow( rr, exponent );
  297. // Velocity
  298. const vel = maxVel * Math.pow( rr, velExponent );
  299. const vx = vel * z + ( Math.random() * 2 - 1 ) * randVel;
  300. const vy = ( Math.random() * 2 - 1 ) * randVel * 0.05;
  301. const vz = - vel * x + ( Math.random() * 2 - 1 ) * randVel;
  302. x *= rExp;
  303. z *= rExp;
  304. const y = ( Math.random() * 2 - 1 ) * height;
  305. const mass = Math.random() * maxMass + 1;
  306. // Fill in texture values
  307. posArray[ k + 0 ] = x;
  308. posArray[ k + 1 ] = y;
  309. posArray[ k + 2 ] = z;
  310. posArray[ k + 3 ] = 1;
  311. velArray[ k + 0 ] = vx;
  312. velArray[ k + 1 ] = vy;
  313. velArray[ k + 2 ] = vz;
  314. velArray[ k + 3 ] = mass;
  315. }
  316. }
  317. function onWindowResize() {
  318. camera.aspect = window.innerWidth / window.innerHeight;
  319. camera.updateProjectionMatrix();
  320. renderer.setSize( window.innerWidth, window.innerHeight );
  321. particleUniforms[ 'cameraConstant' ].value = getCameraConstant( camera );
  322. }
  323. function dynamicValuesChanger() {
  324. velocityUniforms[ 'gravityConstant' ].value = effectController.gravityConstant;
  325. velocityUniforms[ 'density' ].value = effectController.density;
  326. particleUniforms[ 'density' ].value = effectController.density;
  327. }
  328. function initGUI() {
  329. const gui = new GUI( { width: 280 } );
  330. const folder1 = gui.addFolder( 'Dynamic parameters' );
  331. folder1.add( effectController, 'gravityConstant', 0.0, 1000.0, 0.05 ).onChange( dynamicValuesChanger );
  332. folder1.add( effectController, 'density', 0.0, 10.0, 0.001 ).onChange( dynamicValuesChanger );
  333. const folder2 = gui.addFolder( 'Static parameters' );
  334. folder2.add( effectController, 'radius', 10.0, 1000.0, 1.0 );
  335. folder2.add( effectController, 'height', 0.0, 50.0, 0.01 );
  336. folder2.add( effectController, 'exponent', 0.0, 2.0, 0.001 );
  337. folder2.add( effectController, 'maxMass', 1.0, 50.0, 0.1 );
  338. folder2.add( effectController, 'velocity', 0.0, 150.0, 0.1 );
  339. folder2.add( effectController, 'velocityExponent', 0.0, 1.0, 0.01 );
  340. folder2.add( effectController, 'randVelocity', 0.0, 50.0, 0.1 );
  341. const buttonRestart = {
  342. restartSimulation: function () {
  343. restartSimulation();
  344. }
  345. };
  346. folder2.add( buttonRestart, 'restartSimulation' );
  347. folder1.open();
  348. folder2.open();
  349. }
  350. function getCameraConstant( camera ) {
  351. return window.innerHeight / ( Math.tan( THREE.MathUtils.DEG2RAD * 0.5 * camera.fov ) / camera.zoom );
  352. }
  353. function animate() {
  354. render();
  355. stats.update();
  356. }
  357. function render() {
  358. gpuCompute.compute();
  359. particleUniforms[ 'texturePosition' ].value = gpuCompute.getCurrentRenderTarget( positionVariable ).texture;
  360. particleUniforms[ 'textureVelocity' ].value = gpuCompute.getCurrentRenderTarget( velocityVariable ).texture;
  361. renderer.render( scene, camera );
  362. }
  363. </script>
  364. </body>
  365. </html>