Code viewer for World: webgl_instancing_scatter
//ported from threejs examples
//https://threejs.org/examples/#webgl_instancing_scatter



//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';
			import { GPUStatsPanel } from '/uploads/threejs/GPUStatsPanel.js';

            import { GUI } from '/uploads/threejs/dat.gui.module.js';
			import { OrbitControls } from '/uploads/threejs/OrbitControls.js';
			import { Line2 } from '/uploads/threejs/Line2.js';
			import { LineMaterial } from '/uploads/threejs/LineMaterial.js';
			import { LineGeometry } from '/uploads/threejs/LineGeometry.js';
			import * as GeometryUtils from '/uploads/threejs/GeometryUtils.js';

			let line, renderer, scene, camera, camera2, controls;
			let line1;
			let matLine, matLineBasic, matLineDashed;
			let stats, gpuPanel;
			let gui;

			// viewport
			let insetWidth;
			let insetHeight;

			init();
			animate();

			function init() {

				renderer = new THREE.WebGLRenderer( { antialias: true } );
				renderer.setPixelRatio( window.devicePixelRatio );
				renderer.setClearColor( 0x000000, 0.0 );
				renderer.setSize( window.innerWidth, window.innerHeight );
				document.body.appendChild( renderer.domElement );

				scene = new THREE.Scene();

				camera = new THREE.PerspectiveCamera( 40, window.innerWidth / window.innerHeight, 1, 1000 );
				camera.position.set( - 40, 0, 60 );

				camera2 = new THREE.PerspectiveCamera( 40, 1, 1, 1000 );
				camera2.position.copy( camera.position );

				controls = new OrbitControls( camera, renderer.domElement );
				controls.minDistance = 10;
				controls.maxDistance = 500;


				// Position and THREE.Color Data

				const positions = [];
				const colors = [];

				const points = GeometryUtils.hilbert3D( new THREE.Vector3( 0, 0, 0 ), 20.0, 1, 0, 1, 2, 3, 4, 5, 6, 7 );

				const spline = new THREE.CatmullRomCurve3( points );
				const divisions = Math.round( 12 * points.length );
				const point = new THREE.Vector3();
				const color = new THREE.Color();

				for ( let i = 0, l = divisions; i < l; i ++ ) {

					const t = i / l;

					spline.getPoint( t, point );
					positions.push( point.x, point.y, point.z );

					color.setHSL( t, 1.0, 0.5 );
					colors.push( color.r, color.g, color.b );

				}


				// Line2 ( LineGeometry, LineMaterial )

				const geometry = new LineGeometry();
				geometry.setPositions( positions );
				geometry.setColors( colors );

				matLine = new LineMaterial( {

					color: 0xffffff,
					linewidth: 5, // in world units with size attenuation, pixels otherwise
					vertexColors: true,
					
					//resolution:  // to be set by renderer, eventually
					dashed: false,
					alphaToCoverage: true,

				} );

				line = new Line2( geometry, matLine );
				line.computeLineDistances();
				line.scale.set( 1, 1, 1 );
				scene.add( line );


				// THREE.Line ( THREE.BufferGeometry, THREE.LineBasicMaterial ) - rendered with gl.LINE_STRIP

				const geo = new THREE.BufferGeometry();
				geo.setAttribute( 'position', new THREE.Float32BufferAttribute( positions, 3 ) );
				geo.setAttribute( 'color', new THREE.Float32BufferAttribute( colors, 3 ) );

				matLineBasic = new THREE.LineBasicMaterial( { vertexColors: true } );
				matLineDashed = new THREE.LineDashedMaterial( { vertexColors: true, scale: 2, dashSize: 1, gapSize: 1 } );

				line1 = new THREE.Line( geo, matLineBasic );
				line1.computeLineDistances();
				line1.visible = false;
				scene.add( line1 );

				//

				window.addEventListener( 'resize', onWindowResize );
				onWindowResize();

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

				gpuPanel = new GPUStatsPanel( renderer.getContext() );
				stats.addPanel( gpuPanel );
				stats.showPanel( 0 );

				initGui();

			}

			function onWindowResize() {

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

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

				insetWidth = window.innerHeight / 4; // square
				insetHeight = window.innerHeight / 4;

				camera2.aspect = insetWidth / insetHeight;
				camera2.updateProjectionMatrix();

			}

			function animate() {

				requestAnimationFrame( animate );

				stats.update();

				// main scene

				renderer.setClearColor( 0x000000, 0 );

				renderer.setViewport( 0, 0, window.innerWidth, window.innerHeight );

				// renderer will set this eventually
				matLine.resolution.set( window.innerWidth, window.innerHeight ); // resolution of the viewport

				gpuPanel.startQuery();
				renderer.render( scene, camera );
				gpuPanel.endQuery();

				// inset scene

				renderer.setClearColor( 0x222222, 1 );

				renderer.clearDepth(); // important!

				renderer.setScissorTest( true );

				renderer.setScissor( 20, 20, insetWidth, insetHeight );

				renderer.setViewport( 20, 20, insetWidth, insetHeight );

				camera2.position.copy( camera.position );
				camera2.quaternion.copy( camera.quaternion );

				// renderer will set this eventually
				matLine.resolution.set( insetWidth, insetHeight ); // resolution of the inset viewport

				renderer.render( scene, camera2 );

				renderer.setScissorTest( false );

			}

			//

			function initGui() {

				gui = new GUI();

				const param = {
					'line type': 0,
					'world units': false,
					'width': 5,
					'alphaToCoverage': true,
					'dashed': false,
					'dash scale': 1,
					'dash / gap': 1
				};

				gui.add( param, 'line type', { 'LineGeometry': 0, 'gl.LINE': 1 } ).onChange( function ( val ) {

					switch ( val ) {

						case '0':
							line.visible = true;

							line1.visible = false;

							break;

						case '1':
							line.visible = false;

							line1.visible = true;

							break;

					}

				} );

				gui.add( param, 'world units' ).onChange( function ( val ) {

					matLine.worldUnits = val;
					matLine.needsUpdate = true;

				} );

				gui.add( param, 'width', 1, 10 ).onChange( function ( val ) {

					matLine.linewidth = val;

				} );

				gui.add( param, 'alphaToCoverage' ).onChange( function ( val ) { 

					matLine.alphaToCoverage = val;

				} );

				gui.add( param, 'dashed' ).onChange( function ( val ) {

					matLine.dashed = val;
					line1.material = val ? matLineDashed : matLineBasic;

				} );

				gui.add( param, 'dash scale', 0.5, 2, 0.1 ).onChange( function ( val ) {

					matLine.dashScale = val;
					matLineDashed.scale = val;

				} );

				gui.add( param, 'dash / gap', { '2 : 1': 0, '1 : 1': 1, '1 : 2': 2 } ).onChange( function ( val ) {

					switch ( val ) {

						case '0':
							matLine.dashSize = 2;
							matLine.gapSize = 1;

							matLineDashed.dashSize = 2;
							matLineDashed.gapSize = 1;

							break;

						case '1':
							matLine.dashSize = 1;
							matLine.gapSize = 1;

							matLineDashed.dashSize = 1;
							matLineDashed.gapSize = 1;

							break;

						case '2':
							matLine.dashSize = 1;
							matLine.gapSize = 2;

							matLineDashed.dashSize = 1;
							matLineDashed.gapSize = 2;

							break;

					}

				} );

			}