Code viewer for World: webgl_interactive_raycasti...
//ported from threejs examples
//https://threejs.org/examples/#webgl_interactive_raycasting_points
//https://github.com/mrdoob/three.js/blob/master/examples/webgl_interactive_raycasting_points.html
//load css
            AB.loadCSS ( '/uploads/threeport/main.css' ); 
            AB.newDiv ('container');

            import * as THREE from '/api/threemodule/libs/three.module.js';

          import Stats from '/uploads/threeport/stats.module.js';
			let renderer, scene, camera, stats;
			let pointclouds;
			let raycaster;
			let intersection = null;
			let spheresIndex = 0;
			let clock;
			let toggle = 0;

			const pointer = new THREE.Vector2();
			const spheres = [];

			const threshold = 0.1;
			const pointSize = 0.05;
			const width = 80;
			const length = 160;
			const rotateY = new THREE.Matrix4().makeRotationY( 0.005 );

			init();
			animate();

			function generatePointCloudGeometry( color, width, length ) {

				const geometry = new THREE.BufferGeometry();
				const numPoints = width * length;

				const positions = new Float32Array( numPoints * 3 );
				const colors = new Float32Array( numPoints * 3 );

				let k = 0;

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

					for ( let j = 0; j < length; j ++ ) {

						const u = i / width;
						const v = j / length;
						const x = u - 0.5;
						const y = ( Math.cos( u * Math.PI * 4 ) + Math.sin( v * Math.PI * 8 ) ) / 20;
						const z = v - 0.5;

						positions[ 3 * k ] = x;
						positions[ 3 * k + 1 ] = y;
						positions[ 3 * k + 2 ] = z;

						const intensity = ( y + 0.1 ) * 5;
						colors[ 3 * k ] = color.r * intensity;
						colors[ 3 * k + 1 ] = color.g * intensity;
						colors[ 3 * k + 2 ] = color.b * intensity;

						k ++;

					}

				}

				geometry.setAttribute( 'position', new THREE.BufferAttribute( positions, 3 ) );
				geometry.setAttribute( 'color', new THREE.BufferAttribute( colors, 3 ) );
				geometry.computeBoundingBox();

				return geometry;

			}

			function generatePointcloud( color, width, length ) {

				const geometry = generatePointCloudGeometry( color, width, length );
				const material = new THREE.PointsMaterial( { size: pointSize, vertexColors: true } );

				return new THREE.Points( geometry, material );

			}

			function generateIndexedPointcloud( color, width, length ) {

				const geometry = generatePointCloudGeometry( color, width, length );
				const numPoints = width * length;
				const indices = new Uint16Array( numPoints );

				let k = 0;

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

					for ( let j = 0; j < length; j ++ ) {

						indices[ k ] = k;
						k ++;

					}

				}

				geometry.setIndex( new THREE.BufferAttribute( indices, 1 ) );

				const material = new THREE.PointsMaterial( { size: pointSize, vertexColors: true } );

				return new THREE.Points( geometry, material );

			}

			function generateIndexedWithOffsetPointcloud( color, width, length ) {

				const geometry = generatePointCloudGeometry( color, width, length );
				const numPoints = width * length;
				const indices = new Uint16Array( numPoints );

				let k = 0;

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

					for ( let j = 0; j < length; j ++ ) {

						indices[ k ] = k;
						k ++;

					}

				}

				geometry.setIndex( new THREE.BufferAttribute( indices, 1 ) );
				geometry.addGroup( 0, indices.length );

				const material = new THREE.PointsMaterial( { size: pointSize, vertexColors: true } );

				return new THREE.Points( geometry, material );

			}

			function init() {

				const container = document.getElementById( 'container' );

				scene = new THREE.Scene();

				clock = new THREE.Clock();

				camera = new THREE.PerspectiveCamera( 45, window.innerWidth / window.innerHeight, 1, 10000 );
				camera.position.set( 10, 10, 10 );
				camera.lookAt( scene.position );
				camera.updateMatrix();

				//

				const pcBuffer = generatePointcloud( new THREE.Color( 1, 0, 0 ), width, length );
				pcBuffer.scale.set( 5, 10, 10 );
				pcBuffer.position.set( - 5, 0, 0 );
				scene.add( pcBuffer );

				const pcIndexed = generateIndexedPointcloud( new THREE.Color( 0, 1, 0 ), width, length );
				pcIndexed.scale.set( 5, 10, 10 );
				pcIndexed.position.set( 0, 0, 0 );
				scene.add( pcIndexed );

				const pcIndexedOffset = generateIndexedWithOffsetPointcloud( new THREE.Color( 0, 1, 1 ), width, length );
				pcIndexedOffset.scale.set( 5, 10, 10 );
				pcIndexedOffset.position.set( 5, 0, 0 );
				scene.add( pcIndexedOffset );

				pointclouds = [ pcBuffer, pcIndexed, pcIndexedOffset ];

				//

				const sphereGeometry = new THREE.SphereGeometry( 0.1, 32, 32 );
				const sphereMaterial = new THREE.MeshBasicMaterial( { color: 0xff0000 } );

				for ( let i = 0; i < 40; i ++ ) {

					const sphere = new THREE.Mesh( sphereGeometry, sphereMaterial );
					scene.add( sphere );
					spheres.push( sphere );

				}

				//

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

				//

				raycaster = new THREE.Raycaster();
				raycaster.params.Points.threshold = threshold;

				//

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

				//

				window.addEventListener( 'resize', onWindowResize );
				document.addEventListener( 'pointermove', onPointerMove );

			}

			function onPointerMove( event ) {

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

			}

			function onWindowResize() {

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

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

			}

			function animate() {

				requestAnimationFrame( animate );

				render();
				stats.update();

			}

			function render() {

				camera.applyMatrix4( rotateY );
				camera.updateMatrixWorld();

				raycaster.setFromCamera( pointer, camera );

				const intersections = raycaster.intersectObjects( pointclouds );
				intersection = ( intersections.length ) > 0 ? intersections[ 0 ] : null;

				if ( toggle > 0.02 && intersection !== null ) {

					spheres[ spheresIndex ].position.copy( intersection.point );
					spheres[ spheresIndex ].scale.set( 1, 1, 1 );
					spheresIndex = ( spheresIndex + 1 ) % spheres.length;

					toggle = 0;

				}

				for ( let i = 0; i < spheres.length; i ++ ) {

					const sphere = spheres[ i ];
					sphere.scale.multiplyScalar( 0.98 );
					sphere.scale.clampScalar( 0.01, 1 );

				}

				toggle += clock.getDelta();

				renderer.render( scene, camera );

			}