webgl_volume_instancing.html 6.1 KB

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  1. <!DOCTYPE html>
  2. <html lang="en">
  3. <head>
  4. <title>three.js webgl2 - volume - instancing</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 - instancing
  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 { VOXLoader, VOXData3DTexture } from 'three/addons/loaders/VOXLoader.js';
  25. let renderer, scene, camera, controls, clock;
  26. init();
  27. function init() {
  28. renderer = new THREE.WebGLRenderer();
  29. renderer.setPixelRatio( window.devicePixelRatio );
  30. renderer.setSize( window.innerWidth, window.innerHeight );
  31. renderer.setAnimationLoop( animate );
  32. document.body.appendChild( renderer.domElement );
  33. scene = new THREE.Scene();
  34. camera = new THREE.PerspectiveCamera( 60, window.innerWidth / window.innerHeight, 0.1, 1000 );
  35. camera.position.set( 0, 0, 4 );
  36. controls = new OrbitControls( camera, renderer.domElement );
  37. controls.autoRotate = true;
  38. controls.autoRotateSpeed = - 1.0;
  39. controls.enableDamping = true;
  40. clock = new THREE.Clock();
  41. // Material
  42. const vertexShader = /* glsl */`
  43. in vec3 position;
  44. in mat4 instanceMatrix;
  45. uniform mat4 modelMatrix;
  46. uniform mat4 modelViewMatrix;
  47. uniform mat4 projectionMatrix;
  48. uniform vec3 cameraPos;
  49. out vec3 vOrigin;
  50. out vec3 vDirection;
  51. void main() {
  52. vec4 mvPosition = modelViewMatrix * instanceMatrix * vec4( position, 1.0 );
  53. vOrigin = vec3( inverse( instanceMatrix * modelMatrix ) * vec4( cameraPos, 1.0 ) ).xyz;
  54. vDirection = position - vOrigin;
  55. gl_Position = projectionMatrix * mvPosition;
  56. }
  57. `;
  58. const fragmentShader = /* glsl */`
  59. precision highp float;
  60. precision highp sampler3D;
  61. uniform mat4 modelViewMatrix;
  62. uniform mat4 projectionMatrix;
  63. in vec3 vOrigin;
  64. in vec3 vDirection;
  65. out vec4 color;
  66. uniform sampler3D map;
  67. uniform float threshold;
  68. uniform float steps;
  69. vec2 hitBox( vec3 orig, vec3 dir ) {
  70. const vec3 box_min = vec3( - 0.5 );
  71. const vec3 box_max = vec3( 0.5 );
  72. vec3 inv_dir = 1.0 / dir;
  73. vec3 tmin_tmp = ( box_min - orig ) * inv_dir;
  74. vec3 tmax_tmp = ( box_max - orig ) * inv_dir;
  75. vec3 tmin = min( tmin_tmp, tmax_tmp );
  76. vec3 tmax = max( tmin_tmp, tmax_tmp );
  77. float t0 = max( tmin.x, max( tmin.y, tmin.z ) );
  78. float t1 = min( tmax.x, min( tmax.y, tmax.z ) );
  79. return vec2( t0, t1 );
  80. }
  81. float sample1( vec3 p ) {
  82. return texture( map, p ).r;
  83. }
  84. #define epsilon .0001
  85. vec3 normal( vec3 coord ) {
  86. if ( coord.x < epsilon ) return vec3( 1.0, 0.0, 0.0 );
  87. if ( coord.y < epsilon ) return vec3( 0.0, 1.0, 0.0 );
  88. if ( coord.z < epsilon ) return vec3( 0.0, 0.0, 1.0 );
  89. if ( coord.x > 1.0 - epsilon ) return vec3( - 1.0, 0.0, 0.0 );
  90. if ( coord.y > 1.0 - epsilon ) return vec3( 0.0, - 1.0, 0.0 );
  91. if ( coord.z > 1.0 - epsilon ) return vec3( 0.0, 0.0, - 1.0 );
  92. float step = 0.01;
  93. float x = sample1( coord + vec3( - step, 0.0, 0.0 ) ) - sample1( coord + vec3( step, 0.0, 0.0 ) );
  94. float y = sample1( coord + vec3( 0.0, - step, 0.0 ) ) - sample1( coord + vec3( 0.0, step, 0.0 ) );
  95. float z = sample1( coord + vec3( 0.0, 0.0, - step ) ) - sample1( coord + vec3( 0.0, 0.0, step ) );
  96. return normalize( vec3( x, y, z ) );
  97. }
  98. void main(){
  99. vec3 rayDir = normalize( vDirection );
  100. vec2 bounds = hitBox( vOrigin, rayDir );
  101. if ( bounds.x > bounds.y ) discard;
  102. bounds.x = max( bounds.x, 0.0 );
  103. vec3 p = vOrigin + bounds.x * rayDir;
  104. vec3 inc = 1.0 / abs( rayDir );
  105. float delta = min( inc.x, min( inc.y, inc.z ) );
  106. delta /= 50.0;
  107. for ( float t = bounds.x; t < bounds.y; t += delta ) {
  108. float d = sample1( p + 0.5 );
  109. if ( d > 0.5 ) {
  110. color.rgb = p * 2.0; // normal( p + 0.5 ); // * 0.5 + ( p * 1.5 + 0.25 );
  111. color.a = 1.;
  112. break;
  113. }
  114. p += rayDir * delta;
  115. }
  116. if ( color.a == 0.0 ) discard;
  117. }
  118. `;
  119. const loader = new VOXLoader();
  120. loader.load( 'models/vox/menger.vox', function ( chunks ) {
  121. for ( let i = 0; i < chunks.length; i ++ ) {
  122. const chunk = chunks[ i ];
  123. const geometry = new THREE.BoxGeometry( 1, 1, 1 );
  124. const material = new THREE.RawShaderMaterial( {
  125. glslVersion: THREE.GLSL3,
  126. uniforms: {
  127. map: { value: new VOXData3DTexture( chunk ) },
  128. cameraPos: { value: new THREE.Vector3() }
  129. },
  130. vertexShader,
  131. fragmentShader,
  132. side: THREE.BackSide
  133. } );
  134. const mesh = new THREE.InstancedMesh( geometry, material, 50000 );
  135. mesh.onBeforeRender = function () {
  136. this.material.uniforms.cameraPos.value.copy( camera.position );
  137. };
  138. const transform = new THREE.Object3D();
  139. for ( let i = 0; i < mesh.count; i ++ ) {
  140. transform.position.random().subScalar( 0.5 ).multiplyScalar( 150 );
  141. transform.rotation.x = Math.random() * Math.PI;
  142. transform.rotation.y = Math.random() * Math.PI;
  143. transform.rotation.z = Math.random() * Math.PI;
  144. transform.updateMatrix();
  145. mesh.setMatrixAt( i, transform.matrix );
  146. }
  147. scene.add( mesh );
  148. }
  149. } );
  150. window.addEventListener( 'resize', onWindowResize );
  151. }
  152. function onWindowResize() {
  153. camera.aspect = window.innerWidth / window.innerHeight;
  154. camera.updateProjectionMatrix();
  155. renderer.setSize( window.innerWidth, window.innerHeight );
  156. }
  157. function animate() {
  158. const delta = clock.getDelta();
  159. controls.update( delta );
  160. renderer.render( scene, camera );
  161. }
  162. </script>
  163. </body>
  164. </html>