webgl2_volume_perlin.html 6.6 KB

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  1. <!DOCTYPE html>
  2. <html lang="en">
  3. <head>
  4. <title>three.js webgl2 - volume</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
  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, 2 );
  45. new OrbitControls( camera, renderer.domElement );
  46. // Texture
  47. const size = 128;
  48. const data = new Uint8Array( size * size * size );
  49. let i = 0;
  50. const perlin = new ImprovedNoise();
  51. const vector = new THREE.Vector3();
  52. for ( let z = 0; z < size; z ++ ) {
  53. for ( let y = 0; y < size; y ++ ) {
  54. for ( let x = 0; x < size; x ++ ) {
  55. vector.set( x, y, z ).divideScalar( size );
  56. const d = perlin.noise( vector.x * 6.5, vector.y * 6.5, vector.z * 6.5 );
  57. data[ i ++ ] = d * 128 + 128;
  58. }
  59. }
  60. }
  61. const texture = new THREE.Data3DTexture( data, size, size, size );
  62. texture.format = THREE.RedFormat;
  63. texture.minFilter = THREE.LinearFilter;
  64. texture.magFilter = THREE.LinearFilter;
  65. texture.unpackAlignment = 1;
  66. texture.needsUpdate = true;
  67. // Material
  68. const vertexShader = /* glsl */`
  69. in vec3 position;
  70. uniform mat4 modelMatrix;
  71. uniform mat4 modelViewMatrix;
  72. uniform mat4 projectionMatrix;
  73. uniform vec3 cameraPos;
  74. out vec3 vOrigin;
  75. out vec3 vDirection;
  76. void main() {
  77. vec4 mvPosition = modelViewMatrix * vec4( position, 1.0 );
  78. vOrigin = vec3( inverse( modelMatrix ) * vec4( cameraPos, 1.0 ) ).xyz;
  79. vDirection = position - vOrigin;
  80. gl_Position = projectionMatrix * mvPosition;
  81. }
  82. `;
  83. const fragmentShader = /* glsl */`
  84. precision highp float;
  85. precision highp sampler3D;
  86. uniform mat4 modelViewMatrix;
  87. uniform mat4 projectionMatrix;
  88. in vec3 vOrigin;
  89. in vec3 vDirection;
  90. out vec4 color;
  91. uniform sampler3D map;
  92. uniform float threshold;
  93. uniform float steps;
  94. vec2 hitBox( vec3 orig, vec3 dir ) {
  95. const vec3 box_min = vec3( - 0.5 );
  96. const vec3 box_max = vec3( 0.5 );
  97. vec3 inv_dir = 1.0 / dir;
  98. vec3 tmin_tmp = ( box_min - orig ) * inv_dir;
  99. vec3 tmax_tmp = ( box_max - orig ) * inv_dir;
  100. vec3 tmin = min( tmin_tmp, tmax_tmp );
  101. vec3 tmax = max( tmin_tmp, tmax_tmp );
  102. float t0 = max( tmin.x, max( tmin.y, tmin.z ) );
  103. float t1 = min( tmax.x, min( tmax.y, tmax.z ) );
  104. return vec2( t0, t1 );
  105. }
  106. float sample1( vec3 p ) {
  107. return texture( map, p ).r;
  108. }
  109. #define epsilon .0001
  110. vec3 normal( vec3 coord ) {
  111. if ( coord.x < epsilon ) return vec3( 1.0, 0.0, 0.0 );
  112. if ( coord.y < epsilon ) return vec3( 0.0, 1.0, 0.0 );
  113. if ( coord.z < epsilon ) return vec3( 0.0, 0.0, 1.0 );
  114. if ( coord.x > 1.0 - epsilon ) return vec3( - 1.0, 0.0, 0.0 );
  115. if ( coord.y > 1.0 - epsilon ) return vec3( 0.0, - 1.0, 0.0 );
  116. if ( coord.z > 1.0 - epsilon ) return vec3( 0.0, 0.0, - 1.0 );
  117. float step = 0.01;
  118. float x = sample1( coord + vec3( - step, 0.0, 0.0 ) ) - sample1( coord + vec3( step, 0.0, 0.0 ) );
  119. float y = sample1( coord + vec3( 0.0, - step, 0.0 ) ) - sample1( coord + vec3( 0.0, step, 0.0 ) );
  120. float z = sample1( coord + vec3( 0.0, 0.0, - step ) ) - sample1( coord + vec3( 0.0, 0.0, step ) );
  121. return normalize( vec3( x, y, z ) );
  122. }
  123. void main(){
  124. vec3 rayDir = normalize( vDirection );
  125. vec2 bounds = hitBox( vOrigin, rayDir );
  126. if ( bounds.x > bounds.y ) discard;
  127. bounds.x = max( bounds.x, 0.0 );
  128. vec3 p = vOrigin + bounds.x * rayDir;
  129. vec3 inc = 1.0 / abs( rayDir );
  130. float delta = min( inc.x, min( inc.y, inc.z ) );
  131. delta /= steps;
  132. for ( float t = bounds.x; t < bounds.y; t += delta ) {
  133. float d = sample1( p + 0.5 );
  134. if ( d > threshold ) {
  135. color.rgb = normal( p + 0.5 ) * 0.5 + ( p * 1.5 + 0.25 );
  136. color.a = 1.;
  137. break;
  138. }
  139. p += rayDir * delta;
  140. }
  141. if ( color.a == 0.0 ) discard;
  142. }
  143. `;
  144. const geometry = new THREE.BoxGeometry( 1, 1, 1 );
  145. const material = new THREE.RawShaderMaterial( {
  146. glslVersion: THREE.GLSL3,
  147. uniforms: {
  148. map: { value: texture },
  149. cameraPos: { value: new THREE.Vector3() },
  150. threshold: { value: 0.6 },
  151. steps: { value: 200 }
  152. },
  153. vertexShader,
  154. fragmentShader,
  155. side: THREE.BackSide,
  156. } );
  157. mesh = new THREE.Mesh( geometry, material );
  158. scene.add( mesh );
  159. //
  160. const parameters = { threshold: 0.6, steps: 200 };
  161. function update() {
  162. material.uniforms.threshold.value = parameters.threshold;
  163. material.uniforms.steps.value = parameters.steps;
  164. }
  165. const gui = new GUI();
  166. gui.add( parameters, 'threshold', 0, 1, 0.01 ).onChange( update );
  167. gui.add( parameters, 'steps', 0, 300, 1 ).onChange( update );
  168. window.addEventListener( 'resize', onWindowResize );
  169. }
  170. function onWindowResize() {
  171. camera.aspect = window.innerWidth / window.innerHeight;
  172. camera.updateProjectionMatrix();
  173. renderer.setSize( window.innerWidth, window.innerHeight );
  174. }
  175. function animate() {
  176. requestAnimationFrame( animate );
  177. mesh.material.uniforms.cameraPos.value.copy( camera.position );
  178. renderer.render( scene, camera );
  179. }
  180. </script>
  181. </body>
  182. </html>