webgl2_volume_perlin.html 6.2 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. <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/dat.gui.module.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, 2 );
  34. new OrbitControls( camera, renderer.domElement );
  35. // Texture
  36. const size = 128;
  37. const data = new Uint8Array( size * size * size );
  38. let i = 0;
  39. const perlin = new ImprovedNoise();
  40. const vector = new THREE.Vector3();
  41. for ( let z = 0; z < size; z ++ ) {
  42. for ( let y = 0; y < size; y ++ ) {
  43. for ( let x = 0; x < size; x ++ ) {
  44. vector.set( x, y, z ).divideScalar( size );
  45. const d = perlin.noise( vector.x * 6.5, vector.y * 6.5, vector.z * 6.5 );
  46. data[ i ++ ] = d * 128 + 128;
  47. }
  48. }
  49. }
  50. const texture = new THREE.DataTexture3D( data, size, size, size );
  51. texture.format = THREE.RedFormat;
  52. texture.minFilter = THREE.LinearFilter;
  53. texture.magFilter = THREE.LinearFilter;
  54. texture.unpackAlignment = 1;
  55. // Material
  56. const vertexShader = /* glsl */`
  57. in vec3 position;
  58. uniform mat4 modelMatrix;
  59. uniform mat4 modelViewMatrix;
  60. uniform mat4 projectionMatrix;
  61. uniform vec3 cameraPos;
  62. out vec3 vOrigin;
  63. out vec3 vDirection;
  64. void main() {
  65. vec4 mvPosition = modelViewMatrix * vec4( position, 1.0 );
  66. vOrigin = vec3( inverse( modelMatrix ) * vec4( cameraPos, 1.0 ) ).xyz;
  67. vDirection = position - vOrigin;
  68. gl_Position = projectionMatrix * mvPosition;
  69. }
  70. `;
  71. const fragmentShader = /* glsl */`
  72. precision highp float;
  73. precision highp sampler3D;
  74. uniform mat4 modelViewMatrix;
  75. uniform mat4 projectionMatrix;
  76. in vec3 vOrigin;
  77. in vec3 vDirection;
  78. out vec4 color;
  79. uniform sampler3D map;
  80. uniform float threshold;
  81. uniform float steps;
  82. vec2 hitBox( vec3 orig, vec3 dir ) {
  83. const vec3 box_min = vec3( - 0.5 );
  84. const vec3 box_max = vec3( 0.5 );
  85. vec3 inv_dir = 1.0 / dir;
  86. vec3 tmin_tmp = ( box_min - orig ) * inv_dir;
  87. vec3 tmax_tmp = ( box_max - orig ) * inv_dir;
  88. vec3 tmin = min( tmin_tmp, tmax_tmp );
  89. vec3 tmax = max( tmin_tmp, tmax_tmp );
  90. float t0 = max( tmin.x, max( tmin.y, tmin.z ) );
  91. float t1 = min( tmax.x, min( tmax.y, tmax.z ) );
  92. return vec2( t0, t1 );
  93. }
  94. float sample1( vec3 p ) {
  95. return texture( map, p ).r;
  96. }
  97. #define epsilon .0001
  98. vec3 normal( vec3 coord ) {
  99. if ( coord.x < epsilon ) return vec3( 1.0, 0.0, 0.0 );
  100. if ( coord.y < epsilon ) return vec3( 0.0, 1.0, 0.0 );
  101. if ( coord.z < epsilon ) return vec3( 0.0, 0.0, 1.0 );
  102. if ( coord.x > 1.0 - epsilon ) return vec3( - 1.0, 0.0, 0.0 );
  103. if ( coord.y > 1.0 - epsilon ) return vec3( 0.0, - 1.0, 0.0 );
  104. if ( coord.z > 1.0 - epsilon ) return vec3( 0.0, 0.0, - 1.0 );
  105. float step = 0.01;
  106. float x = sample1( coord + vec3( - step, 0.0, 0.0 ) ) - sample1( coord + vec3( step, 0.0, 0.0 ) );
  107. float y = sample1( coord + vec3( 0.0, - step, 0.0 ) ) - sample1( coord + vec3( 0.0, step, 0.0 ) );
  108. float z = sample1( coord + vec3( 0.0, 0.0, - step ) ) - sample1( coord + vec3( 0.0, 0.0, step ) );
  109. return normalize( vec3( x, y, z ) );
  110. }
  111. void main(){
  112. vec3 rayDir = normalize( vDirection );
  113. vec2 bounds = hitBox( vOrigin, rayDir );
  114. if ( bounds.x > bounds.y ) discard;
  115. bounds.x = max( bounds.x, 0.0 );
  116. vec3 p = vOrigin + bounds.x * rayDir;
  117. vec3 inc = 1.0 / abs( rayDir );
  118. float delta = min( inc.x, min( inc.y, inc.z ) );
  119. delta /= steps;
  120. for ( float t = bounds.x; t < bounds.y; t += delta ) {
  121. float d = sample1( p + 0.5 );
  122. if ( d > threshold ) {
  123. color.rgb = normal( p + 0.5 ) * 0.5 + ( p * 1.5 + 0.25 );
  124. color.a = 1.;
  125. break;
  126. }
  127. p += rayDir * delta;
  128. }
  129. if ( color.a == 0.0 ) discard;
  130. }
  131. `;
  132. const geometry = new THREE.BoxGeometry( 1, 1, 1 );
  133. const material = new THREE.RawShaderMaterial( {
  134. glslVersion: THREE.GLSL3,
  135. uniforms: {
  136. map: { value: texture },
  137. cameraPos: { value: new THREE.Vector3() },
  138. threshold: { value: 0.6 },
  139. steps: { value: 200 }
  140. },
  141. vertexShader,
  142. fragmentShader,
  143. side: THREE.BackSide,
  144. } );
  145. mesh = new THREE.Mesh( geometry, material );
  146. scene.add( mesh );
  147. //
  148. const parameters = { threshold: 0.6, steps: 200 };
  149. function update() {
  150. material.uniforms.threshold.value = parameters.threshold;
  151. material.uniforms.steps.value = parameters.steps;
  152. }
  153. const gui = new GUI();
  154. gui.add( parameters, 'threshold', 0, 1, 0.01 ).onChange( update );
  155. gui.add( parameters, 'steps', 0, 300, 1 ).onChange( update );
  156. window.addEventListener( 'resize', onWindowResize );
  157. }
  158. function onWindowResize() {
  159. camera.aspect = window.innerWidth / window.innerHeight;
  160. camera.updateProjectionMatrix();
  161. renderer.setSize( window.innerWidth, window.innerHeight );
  162. }
  163. function animate() {
  164. requestAnimationFrame( animate );
  165. mesh.material.uniforms.cameraPos.value.copy( camera.position );
  166. renderer.render( scene, camera );
  167. }
  168. </script>
  169. </body>
  170. </html>