webgl2_volume_instancing.html 6.2 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. import WebGL from 'three/addons/capabilities/WebGL.js';
  26. if ( WebGL.isWebGL2Available() === false ) {
  27. document.body.appendChild( WebGL.getWebGL2ErrorMessage() );
  28. }
  29. let renderer, scene, camera, controls, clock;
  30. init();
  31. animate();
  32. function init() {
  33. renderer = new THREE.WebGLRenderer();
  34. renderer.setPixelRatio( window.devicePixelRatio );
  35. renderer.setSize( window.innerWidth, window.innerHeight );
  36. document.body.appendChild( renderer.domElement );
  37. scene = new THREE.Scene();
  38. camera = new THREE.PerspectiveCamera( 60, window.innerWidth / window.innerHeight, 0.1, 1000 );
  39. camera.position.set( 0, 0, 4 );
  40. controls = new OrbitControls( camera, renderer.domElement );
  41. controls.autoRotate = true;
  42. controls.autoRotateSpeed = - 1.0;
  43. controls.enableDamping = true;
  44. clock = new THREE.Clock();
  45. // Material
  46. const vertexShader = /* glsl */`
  47. in vec3 position;
  48. in mat4 instanceMatrix;
  49. uniform mat4 modelMatrix;
  50. uniform mat4 modelViewMatrix;
  51. uniform mat4 projectionMatrix;
  52. uniform vec3 cameraPos;
  53. out vec3 vOrigin;
  54. out vec3 vDirection;
  55. void main() {
  56. vec4 mvPosition = modelViewMatrix * instanceMatrix * vec4( position, 1.0 );
  57. vOrigin = vec3( inverse( instanceMatrix * modelMatrix ) * vec4( cameraPos, 1.0 ) ).xyz;
  58. vDirection = position - vOrigin;
  59. gl_Position = projectionMatrix * mvPosition;
  60. }
  61. `;
  62. const fragmentShader = /* glsl */`
  63. precision highp float;
  64. precision highp sampler3D;
  65. uniform mat4 modelViewMatrix;
  66. uniform mat4 projectionMatrix;
  67. in vec3 vOrigin;
  68. in vec3 vDirection;
  69. out vec4 color;
  70. uniform sampler3D map;
  71. uniform float threshold;
  72. uniform float steps;
  73. vec2 hitBox( vec3 orig, vec3 dir ) {
  74. const vec3 box_min = vec3( - 0.5 );
  75. const vec3 box_max = vec3( 0.5 );
  76. vec3 inv_dir = 1.0 / dir;
  77. vec3 tmin_tmp = ( box_min - orig ) * inv_dir;
  78. vec3 tmax_tmp = ( box_max - orig ) * inv_dir;
  79. vec3 tmin = min( tmin_tmp, tmax_tmp );
  80. vec3 tmax = max( tmin_tmp, tmax_tmp );
  81. float t0 = max( tmin.x, max( tmin.y, tmin.z ) );
  82. float t1 = min( tmax.x, min( tmax.y, tmax.z ) );
  83. return vec2( t0, t1 );
  84. }
  85. float sample1( vec3 p ) {
  86. return texture( map, p ).r;
  87. }
  88. #define epsilon .0001
  89. vec3 normal( vec3 coord ) {
  90. if ( coord.x < epsilon ) return vec3( 1.0, 0.0, 0.0 );
  91. if ( coord.y < epsilon ) return vec3( 0.0, 1.0, 0.0 );
  92. if ( coord.z < epsilon ) return vec3( 0.0, 0.0, 1.0 );
  93. if ( coord.x > 1.0 - epsilon ) return vec3( - 1.0, 0.0, 0.0 );
  94. if ( coord.y > 1.0 - epsilon ) return vec3( 0.0, - 1.0, 0.0 );
  95. if ( coord.z > 1.0 - epsilon ) return vec3( 0.0, 0.0, - 1.0 );
  96. float step = 0.01;
  97. float x = sample1( coord + vec3( - step, 0.0, 0.0 ) ) - sample1( coord + vec3( step, 0.0, 0.0 ) );
  98. float y = sample1( coord + vec3( 0.0, - step, 0.0 ) ) - sample1( coord + vec3( 0.0, step, 0.0 ) );
  99. float z = sample1( coord + vec3( 0.0, 0.0, - step ) ) - sample1( coord + vec3( 0.0, 0.0, step ) );
  100. return normalize( vec3( x, y, z ) );
  101. }
  102. void main(){
  103. vec3 rayDir = normalize( vDirection );
  104. vec2 bounds = hitBox( vOrigin, rayDir );
  105. if ( bounds.x > bounds.y ) discard;
  106. bounds.x = max( bounds.x, 0.0 );
  107. vec3 p = vOrigin + bounds.x * rayDir;
  108. vec3 inc = 1.0 / abs( rayDir );
  109. float delta = min( inc.x, min( inc.y, inc.z ) );
  110. delta /= 50.0;
  111. for ( float t = bounds.x; t < bounds.y; t += delta ) {
  112. float d = sample1( p + 0.5 );
  113. if ( d > 0.5 ) {
  114. color.rgb = p * 2.0; // normal( p + 0.5 ); // * 0.5 + ( p * 1.5 + 0.25 );
  115. color.a = 1.;
  116. break;
  117. }
  118. p += rayDir * delta;
  119. }
  120. if ( color.a == 0.0 ) discard;
  121. }
  122. `;
  123. const loader = new VOXLoader();
  124. loader.load( 'models/vox/menger.vox', function ( chunks ) {
  125. for ( let i = 0; i < chunks.length; i ++ ) {
  126. const chunk = chunks[ i ];
  127. const geometry = new THREE.BoxGeometry( 1, 1, 1 );
  128. const material = new THREE.RawShaderMaterial( {
  129. glslVersion: THREE.GLSL3,
  130. uniforms: {
  131. map: { value: new VOXData3DTexture( chunk ) },
  132. cameraPos: { value: new THREE.Vector3() }
  133. },
  134. vertexShader,
  135. fragmentShader,
  136. side: THREE.BackSide
  137. } );
  138. const mesh = new THREE.InstancedMesh( geometry, material, 50000 );
  139. mesh.onBeforeRender = function () {
  140. this.material.uniforms.cameraPos.value.copy( camera.position );
  141. };
  142. const transform = new THREE.Object3D();
  143. for ( let i = 0; i < mesh.count; i ++ ) {
  144. transform.position.random().subScalar( 0.5 ).multiplyScalar( 150 );
  145. transform.rotation.x = Math.random() * Math.PI;
  146. transform.rotation.y = Math.random() * Math.PI;
  147. transform.rotation.z = Math.random() * Math.PI;
  148. transform.updateMatrix();
  149. mesh.setMatrixAt( i, transform.matrix );
  150. }
  151. scene.add( mesh );
  152. }
  153. } );
  154. window.addEventListener( 'resize', onWindowResize );
  155. }
  156. function onWindowResize() {
  157. camera.aspect = window.innerWidth / window.innerHeight;
  158. camera.updateProjectionMatrix();
  159. renderer.setSize( window.innerWidth, window.innerHeight );
  160. }
  161. function animate() {
  162. requestAnimationFrame( animate );
  163. const delta = clock.getDelta();
  164. controls.update( delta );
  165. renderer.render( scene, camera );
  166. }
  167. </script>
  168. </body>
  169. </html>