examples/webgl_math_obb.html

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		<title>three.js webgl - math - OBB</title>
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		<div id="container"></div>
		<div id="info">
			<a href="https://threejs.org" target="_blank" rel="noopener noreferrer">three.js</a> - OBB (Oriented Bounding Box)
		</div>

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

		<script type="module">

			import * as THREE from 'three';

			import { OBB } from 'three/addons/math/OBB.js';
			import { OrbitControls } from 'three/addons/controls/OrbitControls.js';

			import Stats from 'three/addons/libs/stats.module.js';

			let camera, scene, renderer, clock, controls, stats, raycaster, hitbox;

			const objects = [], mouse = new THREE.Vector2();

			init();

			function init() {

				camera = new THREE.PerspectiveCamera( 70, window.innerWidth / window.innerHeight, 1, 1000 );
				camera.position.set( 0, 0, 75 );

				scene = new THREE.Scene();
				scene.background = new THREE.Color( 0xffffff );

				clock = new THREE.Clock();

				raycaster = new THREE.Raycaster();

				const hemiLight = new THREE.HemisphereLight( 0xffffff, 0x222222, 4 );
				hemiLight.position.set( 1, 1, 1 );
				scene.add( hemiLight );

				const size = new THREE.Vector3( 10, 5, 6 );
				const geometry = new THREE.BoxGeometry( size.x, size.y, size.z );

				// setup OBB on geometry level (doing this manually for now)

				geometry.userData.obb = new OBB();
				geometry.userData.obb.halfSize.copy( size ).multiplyScalar( 0.5 );

				for ( let i = 0; i < 100; i ++ ) {

					const object = new THREE.Mesh( geometry, new THREE.MeshLambertMaterial( { color: 0x00ff00 } ) );
					object.matrixAutoUpdate = false;

					object.position.x = Math.random() * 80 - 40;
					object.position.y = Math.random() * 80 - 40;
					object.position.z = Math.random() * 80 - 40;

					object.rotation.x = Math.random() * 2 * Math.PI;
					object.rotation.y = Math.random() * 2 * Math.PI;
					object.rotation.z = Math.random() * 2 * Math.PI;

					object.scale.x = Math.random() + 0.5;
					object.scale.y = Math.random() + 0.5;
					object.scale.z = Math.random() + 0.5;

					scene.add( object );

					// bounding volume on object level (this will reflect the current world transform)

					object.userData.obb = new OBB();

					objects.push( object );

				}

				//

				hitbox = new THREE.Mesh( geometry, new THREE.MeshBasicMaterial( { color: 0x000000, wireframe: true } ) );

				//

				renderer = new THREE.WebGLRenderer( { antialias: true } );
				renderer.setPixelRatio( window.devicePixelRatio );
				renderer.setSize( window.innerWidth, window.innerHeight );
				renderer.setAnimationLoop( animate );
				document.body.appendChild( renderer.domElement );

				//

				controls = new OrbitControls( camera, renderer.domElement );
				controls.enableDamping = true;

				//

				stats = new Stats();
				document.body.appendChild( stats.dom );


				//

				window.addEventListener( 'resize', onWindowResize );

				document.addEventListener( 'click', onClick );

			}

			function onClick( event ) {

				event.preventDefault();

				mouse.x = ( event.clientX / window.innerWidth ) * 2 - 1;
				mouse.y = - ( event.clientY / window.innerHeight ) * 2 + 1;

				raycaster.setFromCamera( mouse, camera );

				const intersectionPoint = new THREE.Vector3();
				const intersections = [];

				for ( let i = 0, il = objects.length; i < il; i ++ ) {

					const object = objects[ i ];
					const obb = object.userData.obb;

					const ray = raycaster.ray;

					if ( obb.intersectRay( ray, intersectionPoint ) !== null ) {

						const distance = ray.origin.distanceTo( intersectionPoint );
						intersections.push( { distance: distance, object: object } );

					}

				}

				if ( intersections.length > 0 ) {

					// determine closest intersection and highlight the respective 3D object

					intersections.sort( sortIntersections );

					intersections[ 0 ].object.add( hitbox );

				} else {

					const parent = hitbox.parent;

					if ( parent ) parent.remove( hitbox );

				}

			}

			function sortIntersections( a, b ) {

				return a.distance - b.distance;

			}

			function onWindowResize() {

				camera.aspect = window.innerWidth / window.innerHeight;
				camera.updateProjectionMatrix();

				renderer.setSize( window.innerWidth, window.innerHeight );

			}

			//

			function animate() {

				controls.update();

				// transform cubes

				const delta = clock.getDelta();

				for ( let i = 0, il = objects.length; i < il; i ++ ) {

					const object = objects[ i ];

					object.rotation.x += delta * Math.PI * 0.20;
					object.rotation.y += delta * Math.PI * 0.1;

					object.updateMatrix();
					object.updateMatrixWorld();

					// update OBB

					object.userData.obb.copy( object.geometry.userData.obb );
					object.userData.obb.applyMatrix4( object.matrixWorld );

					// reset

					object.material.color.setHex( 0x00ff00 );

				}

				// collision detection

				for ( let i = 0, il = objects.length; i < il; i ++ ) {

					const object = objects[ i ];
					const obb = object.userData.obb;

					for ( let j = i + 1, jl = objects.length; j < jl; j ++ ) {

						const objectToTest = objects[ j ];
						const obbToTest = objectToTest.userData.obb;

						// now perform intersection test

						if ( obb.intersectsOBB( obbToTest ) === true ) {

							object.material.color.setHex( 0xff0000 );
							objectToTest.material.color.setHex( 0xff0000 );

						}

					}

				}

				renderer.render( scene, camera );

				stats.update();

			}

	</script>

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