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237 lines
5.8 KiB
237 lines
5.8 KiB
<!DOCTYPE html>
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<html lang="en">
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<head>
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<title>three.js webgl - read float pixels</title>
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<meta charset="utf-8">
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<meta name="viewport" content="width=device-width, user-scalable=no, minimum-scale=1.0, maximum-scale=1.0">
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<link type="text/css" rel="stylesheet" href="main.css">
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</head>
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<body>
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<div id="container"></div>
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<div id="info">
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<a href="https://threejs.org" target="_blank" rel="noopener">three.js</a> read float pixels webgl example<br/>
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<span id="values"></span>
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</div>
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<script id="fragment_shader_screen" type="x-shader/x-fragment">
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varying vec2 vUv;
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uniform sampler2D tDiffuse;
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void main() {
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gl_FragColor = texture2D( tDiffuse, vUv );
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}
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</script>
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<script id="fragment_shader_pass_1" type="x-shader/x-fragment">
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varying vec2 vUv;
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uniform float time;
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void main() {
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float r = vUv.x;
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if( vUv.y < 0.5 ) r = 0.0;
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float g = vUv.y;
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if( vUv.x < 0.5 ) g = 0.0;
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gl_FragColor = vec4( r, g, time, 1.0 );
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}
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</script>
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<script id="vertexShader" type="x-shader/x-vertex">
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varying vec2 vUv;
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void main() {
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vUv = uv;
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gl_Position = projectionMatrix * modelViewMatrix * vec4( position, 1.0 );
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}
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</script>
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<!-- Import maps polyfill -->
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<!-- Remove this when import maps will be widely supported -->
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<script async src="https://unpkg.com/es-module-shims@1.3.6/dist/es-module-shims.js"></script>
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<script type="importmap">
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{
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"imports": {
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"three": "../build/three.module.js",
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"three/addons/": "./jsm/"
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}
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}
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</script>
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<script type="module">
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import * as THREE from 'three';
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import Stats from 'three/addons/libs/stats.module.js';
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let container, stats;
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let cameraRTT, sceneRTT, sceneScreen, renderer, zmesh1, zmesh2;
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let mouseX = 0, mouseY = 0;
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const windowHalfX = window.innerWidth / 2;
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const windowHalfY = window.innerHeight / 2;
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let rtTexture, material, quad;
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let delta = 0.01;
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let valueNode;
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init();
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animate();
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function init() {
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container = document.getElementById( 'container' );
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cameraRTT = new THREE.OrthographicCamera( window.innerWidth / - 2, window.innerWidth / 2, window.innerHeight / 2, window.innerHeight / - 2, - 10000, 10000 );
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cameraRTT.position.z = 100;
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//
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sceneRTT = new THREE.Scene();
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sceneScreen = new THREE.Scene();
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let light = new THREE.DirectionalLight( 0xffffff );
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light.position.set( 0, 0, 1 ).normalize();
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sceneRTT.add( light );
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light = new THREE.DirectionalLight( 0xffaaaa, 1.5 );
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light.position.set( 0, 0, - 1 ).normalize();
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sceneRTT.add( light );
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rtTexture = new THREE.WebGLRenderTarget( window.innerWidth, window.innerHeight, { minFilter: THREE.LinearFilter, magFilter: THREE.NearestFilter, format: THREE.RGBAFormat, type: THREE.FloatType } );
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material = new THREE.ShaderMaterial( {
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uniforms: { 'time': { value: 0.0 } },
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vertexShader: document.getElementById( 'vertexShader' ).textContent,
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fragmentShader: document.getElementById( 'fragment_shader_pass_1' ).textContent
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} );
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const materialScreen = new THREE.ShaderMaterial( {
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uniforms: { 'tDiffuse': { value: rtTexture.texture } },
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vertexShader: document.getElementById( 'vertexShader' ).textContent,
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fragmentShader: document.getElementById( 'fragment_shader_screen' ).textContent,
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depthWrite: false
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} );
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const plane = new THREE.PlaneGeometry( window.innerWidth, window.innerHeight );
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quad = new THREE.Mesh( plane, material );
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quad.position.z = - 100;
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sceneRTT.add( quad );
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const geometry = new THREE.TorusGeometry( 100, 25, 15, 30 );
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const mat1 = new THREE.MeshPhongMaterial( { color: 0x555555, specular: 0xffaa00, shininess: 5 } );
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const mat2 = new THREE.MeshPhongMaterial( { color: 0x550000, specular: 0xff2200, shininess: 5 } );
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zmesh1 = new THREE.Mesh( geometry, mat1 );
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zmesh1.position.set( 0, 0, 100 );
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zmesh1.scale.set( 1.5, 1.5, 1.5 );
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sceneRTT.add( zmesh1 );
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zmesh2 = new THREE.Mesh( geometry, mat2 );
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zmesh2.position.set( 0, 150, 100 );
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zmesh2.scale.set( 0.75, 0.75, 0.75 );
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sceneRTT.add( zmesh2 );
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quad = new THREE.Mesh( plane, materialScreen );
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quad.position.z = - 100;
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sceneScreen.add( quad );
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renderer = new THREE.WebGLRenderer();
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renderer.setPixelRatio( window.devicePixelRatio );
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renderer.setSize( window.innerWidth, window.innerHeight );
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renderer.autoClear = false;
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container.appendChild( renderer.domElement );
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stats = new Stats();
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container.appendChild( stats.dom );
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valueNode = document.getElementById( 'values' );
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document.addEventListener( 'mousemove', onDocumentMouseMove );
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}
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function onDocumentMouseMove( event ) {
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mouseX = ( event.clientX - windowHalfX );
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mouseY = ( event.clientY - windowHalfY );
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}
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//
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function animate() {
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requestAnimationFrame( animate );
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render();
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stats.update();
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}
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function render() {
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const time = Date.now() * 0.0015;
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if ( zmesh1 && zmesh2 ) {
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zmesh1.rotation.y = - time;
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zmesh2.rotation.y = - time + Math.PI / 2;
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}
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if ( material.uniforms[ 'time' ].value > 1 || material.uniforms[ 'time' ].value < 0 ) {
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delta *= - 1;
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}
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material.uniforms[ 'time' ].value += delta;
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renderer.clear();
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// Render first scene into texture
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renderer.setRenderTarget( rtTexture );
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renderer.clear();
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renderer.render( sceneRTT, cameraRTT );
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// Render full screen quad with generated texture
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renderer.setRenderTarget( null );
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renderer.render( sceneScreen, cameraRTT );
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const read = new Float32Array( 4 );
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renderer.readRenderTargetPixels( rtTexture, windowHalfX + mouseX, windowHalfY - mouseY, 1, 1, read );
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valueNode.innerHTML = 'r:' + read[ 0 ] + '<br/>g:' + read[ 1 ] + '<br/>b:' + read[ 2 ];
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}
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</script>
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</body>
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</html>
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