examples/webgl_camera.html

<!DOCTYPE html>
<html lang="en">
	<head>
		<title>three.js webgl - cameras</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">
		<style>
			a {
				color: #08f;
			}
			b {
				color: lightgreen;
			}
		</style>
	</head>
	<body>
		<div id="info"><a href="https://threejs.org" target="_blank" rel="noopener">three.js</a> - cameras<br/>
		<b>O</b> orthographic <b>P</b> perspective
		</div>

		<script type="module">

			import * as THREE from '../build/three.module.js';

			import Stats from './jsm/libs/stats.module.js';

			var SCREEN_WIDTH = window.innerWidth;
			var SCREEN_HEIGHT = window.innerHeight;
			var aspect = SCREEN_WIDTH / SCREEN_HEIGHT;

			var container, stats;
			var camera, scene, renderer, mesh;
			var cameraRig, activeCamera, activeHelper;
			var cameraPerspective, cameraOrtho;
			var cameraPerspectiveHelper, cameraOrthoHelper;
			var frustumSize = 600;

			init();
			animate();

			function init() {

				container = document.createElement( 'div' );
				document.body.appendChild( container );

				scene = new THREE.Scene();

				//

				camera = new THREE.PerspectiveCamera( 50, 0.5 * aspect, 1, 10000 );
				camera.position.z = 2500;

				cameraPerspective = new THREE.PerspectiveCamera( 50, 0.5 * aspect, 150, 1000 );

				cameraPerspectiveHelper = new THREE.CameraHelper( cameraPerspective );
				scene.add( cameraPerspectiveHelper );

				//
				cameraOrtho = new THREE.OrthographicCamera( 0.5 * frustumSize * aspect / - 2, 0.5 * frustumSize * aspect / 2, frustumSize / 2, frustumSize / - 2, 150, 1000 );

				cameraOrthoHelper = new THREE.CameraHelper( cameraOrtho );
				scene.add( cameraOrthoHelper );

				//

				activeCamera = cameraPerspective;
				activeHelper = cameraPerspectiveHelper;


				// counteract different front orientation of cameras vs rig

				cameraOrtho.rotation.y = Math.PI;
				cameraPerspective.rotation.y = Math.PI;

				cameraRig = new THREE.Group();

				cameraRig.add( cameraPerspective );
				cameraRig.add( cameraOrtho );

				scene.add( cameraRig );

				//

				mesh = new THREE.Mesh(
					new THREE.SphereBufferGeometry( 100, 16, 8 ),
					new THREE.MeshBasicMaterial( { color: 0xffffff, wireframe: true } )
				);
				scene.add( mesh );

				var mesh2 = new THREE.Mesh(
					new THREE.SphereBufferGeometry( 50, 16, 8 ),
					new THREE.MeshBasicMaterial( { color: 0x00ff00, wireframe: true } )
				);
				mesh2.position.y = 150;
				mesh.add( mesh2 );

				var mesh3 = new THREE.Mesh(
					new THREE.SphereBufferGeometry( 5, 16, 8 ),
					new THREE.MeshBasicMaterial( { color: 0x0000ff, wireframe: true } )
				);
				mesh3.position.z = 150;
				cameraRig.add( mesh3 );

				//

				var geometry = new THREE.BufferGeometry();
				var vertices = [];

				for ( var i = 0; i < 10000; i ++ ) {

					vertices.push( THREE.MathUtils.randFloatSpread( 2000 ) ); // x
					vertices.push( THREE.MathUtils.randFloatSpread( 2000 ) ); // y
					vertices.push( THREE.MathUtils.randFloatSpread( 2000 ) ); // z

				}

				geometry.setAttribute( 'position', new THREE.Float32BufferAttribute( vertices, 3 ) );

				var particles = new THREE.Points( geometry, new THREE.PointsMaterial( { color: 0x888888 } ) );
				scene.add( particles );

				//

				renderer = new THREE.WebGLRenderer( { antialias: true } );
				renderer.setPixelRatio( window.devicePixelRatio );
				renderer.setSize( SCREEN_WIDTH, SCREEN_HEIGHT );
				container.appendChild( renderer.domElement );

				renderer.autoClear = false;

				//

				stats = new Stats();
				container.appendChild( stats.dom );

				//

				window.addEventListener( 'resize', onWindowResize, false );
				document.addEventListener( 'keydown', onKeyDown, false );

			}

			//

			function onKeyDown( event ) {

				switch ( event.keyCode ) {

					case 79: /*O*/

						activeCamera = cameraOrtho;
						activeHelper = cameraOrthoHelper;

						break;

					case 80: /*P*/

						activeCamera = cameraPerspective;
						activeHelper = cameraPerspectiveHelper;

						break;

				}

			}

			//

			function onWindowResize() {

				SCREEN_WIDTH = window.innerWidth;
				SCREEN_HEIGHT = window.innerHeight;
				aspect = SCREEN_WIDTH / SCREEN_HEIGHT;

				renderer.setSize( SCREEN_WIDTH, SCREEN_HEIGHT );

				camera.aspect = 0.5 * aspect;
				camera.updateProjectionMatrix();

				cameraPerspective.aspect = 0.5 * aspect;
				cameraPerspective.updateProjectionMatrix();

				cameraOrtho.left = - 0.5 * frustumSize * aspect / 2;
				cameraOrtho.right = 0.5 * frustumSize * aspect / 2;
				cameraOrtho.top = frustumSize / 2;
				cameraOrtho.bottom = - frustumSize / 2;
				cameraOrtho.updateProjectionMatrix();

			}

			//

			function animate() {

				requestAnimationFrame( animate );

				render();
				stats.update();

			}


			function render() {

				var r = Date.now() * 0.0005;

				mesh.position.x = 700 * Math.cos( r );
				mesh.position.z = 700 * Math.sin( r );
				mesh.position.y = 700 * Math.sin( r );

				mesh.children[ 0 ].position.x = 70 * Math.cos( 2 * r );
				mesh.children[ 0 ].position.z = 70 * Math.sin( r );

				if ( activeCamera === cameraPerspective ) {

					cameraPerspective.fov = 35 + 30 * Math.sin( 0.5 * r );
					cameraPerspective.far = mesh.position.length();
					cameraPerspective.updateProjectionMatrix();

					cameraPerspectiveHelper.update();
					cameraPerspectiveHelper.visible = true;

					cameraOrthoHelper.visible = false;

				} else {

					cameraOrtho.far = mesh.position.length();
					cameraOrtho.updateProjectionMatrix();

					cameraOrthoHelper.update();
					cameraOrthoHelper.visible = true;

					cameraPerspectiveHelper.visible = false;

				}

				cameraRig.lookAt( mesh.position );

				renderer.clear();

				activeHelper.visible = false;

				renderer.setViewport( 0, 0, SCREEN_WIDTH / 2, SCREEN_HEIGHT );
				renderer.render( scene, activeCamera );

				activeHelper.visible = true;

				renderer.setViewport( SCREEN_WIDTH / 2, 0, SCREEN_WIDTH / 2, SCREEN_HEIGHT );
				renderer.render( scene, camera );

			}


		</script>

	</body>
</html>