examples/webgl_postprocessing_masking.html

<!DOCTYPE html>
<html lang="en">
	<head>
		<title>three.js webgl - postprocessing - masking</title>
		<meta charset="utf-8">
		<meta name="viewport" content="width=device-width, user-scalable=no, minimum-scale=1.0, maximum-scale=1.0">
		<link type="text/css" rel="stylesheet" href="main.css">
	</head>
	<body>

		<div id="container"></div>

		<!-- Import maps polyfill -->
		<!-- Remove this when import maps will be widely supported -->
		<script async src="https://unpkg.com/es-module-shims@1.3.6/dist/es-module-shims.js"></script>

		<script type="importmap">
			{
				"imports": {
					"three": "../build/three.module.js",
					"three/addons/": "./jsm/"
				}
			}
		</script>

		<script type="module">

			import * as THREE from 'three';

			import { EffectComposer } from 'three/addons/postprocessing/EffectComposer.js';
			import { ShaderPass } from 'three/addons/postprocessing/ShaderPass.js';
			import { TexturePass } from 'three/addons/postprocessing/TexturePass.js';
			import { ClearPass } from 'three/addons/postprocessing/ClearPass.js';
			import { MaskPass, ClearMaskPass } from 'three/addons/postprocessing/MaskPass.js';
			import { CopyShader } from 'three/addons/shaders/CopyShader.js';

			let camera, composer, renderer;
			let box, torus;

			init();
			animate();

			function init() {

				camera = new THREE.PerspectiveCamera( 50, window.innerWidth / window.innerHeight, 1, 1000 );
				camera.position.z = 10;

				const scene1 = new THREE.Scene();
				const scene2 = new THREE.Scene();

				box = new THREE.Mesh( new THREE.BoxGeometry( 4, 4, 4 ) );
				scene1.add( box );

				torus = new THREE.Mesh( new THREE.TorusGeometry( 3, 1, 16, 32 ) );
				scene2.add( torus );

				renderer = new THREE.WebGLRenderer();
				renderer.setClearColor( 0xe0e0e0 );
				renderer.setPixelRatio( window.devicePixelRatio );
				renderer.setSize( window.innerWidth, window.innerHeight );
				renderer.autoClear = false;
				document.body.appendChild( renderer.domElement );

				//

				const clearPass = new ClearPass();

				const clearMaskPass = new ClearMaskPass();

				const maskPass1 = new MaskPass( scene1, camera );
				const maskPass2 = new MaskPass( scene2, camera );

				const texture1 = new THREE.TextureLoader().load( 'textures/758px-Canestra_di_frutta_(Caravaggio).jpg' );
				texture1.minFilter = THREE.LinearFilter;
				const texture2 = new THREE.TextureLoader().load( 'textures/2294472375_24a3b8ef46_o.jpg' );

				const texturePass1 = new TexturePass( texture1 );
				const texturePass2 = new TexturePass( texture2 );

				const outputPass = new ShaderPass( CopyShader );

				const parameters = {
					stencilBuffer: true
				};

				const renderTarget = new THREE.WebGLRenderTarget( window.innerWidth, window.innerHeight, parameters );

				composer = new EffectComposer( renderer, renderTarget );
				composer.addPass( clearPass );
				composer.addPass( maskPass1 );
				composer.addPass( texturePass1 );
				composer.addPass( clearMaskPass );
				composer.addPass( maskPass2 );
				composer.addPass( texturePass2 );
				composer.addPass( clearMaskPass );
				composer.addPass( outputPass );

				window.addEventListener( 'resize', onWindowResize );

			}

			function onWindowResize() {

				const width = window.innerWidth;
				const height = window.innerHeight;

				camera.aspect = width / height;
				camera.updateProjectionMatrix();

				renderer.setSize( width, height );
				composer.setSize( width, height );

			}

			function animate() {

				requestAnimationFrame( animate );

				const time = performance.now() * 0.001 + 6000;

				box.position.x = Math.cos( time / 1.5 ) * 2;
				box.position.y = Math.sin( time ) * 2;
				box.rotation.x = time;
				box.rotation.y = time / 2;

				torus.position.x = Math.cos( time ) * 2;
				torus.position.y = Math.sin( time / 1.5 ) * 2;
				torus.rotation.x = time;
				torus.rotation.y = time / 2;

				renderer.clear();
				composer.render( time );

			}

		</script>
	</body>
</html>