//ported from three js examples
//https://threejs.org/examples/#webgl_instancing_performance
//https://github.com/mrdoob/three.js/blob/master/examples/webgl_instancing_performance.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';
import { GUI } from '/uploads/threejs/dat.gui.module.js';
import { OrbitControls } from '/uploads/threejs/OrbitControls.js';
import * as BufferGeometryUtils from '/uploads/threejs/BufferGeometryUtils.js';
let container, stats, gui, guiStatsEl;
let camera, controls, scene, renderer, material;
// gui
const Method = {
INSTANCED: 'INSTANCED',
MERGED: 'MERGED',
NAIVE: 'NAIVE'
};
const api = {
method: Method.INSTANCED,
count: 1000
};
//
init();
initMesh();
animate();
//
function clean() {
const meshes = [];
scene.traverse( function ( object ) {
if ( object.isMesh ) meshes.push( object );
} );
for ( let i = 0; i < meshes.length; i ++ ) {
const mesh = meshes[ i ];
mesh.material.dispose();
mesh.geometry.dispose();
scene.remove( mesh );
}
}
const randomizeMatrix = function () {
const position = new THREE.Vector3();
const rotation = new THREE.Euler();
const quaternion = new THREE.Quaternion();
const scale = new THREE.Vector3();
return function ( matrix ) {
position.x = Math.random() * 40 - 20;
position.y = Math.random() * 40 - 20;
position.z = Math.random() * 40 - 20;
rotation.x = Math.random() * 2 * Math.PI;
rotation.y = Math.random() * 2 * Math.PI;
rotation.z = Math.random() * 2 * Math.PI;
quaternion.setFromEuler( rotation );
scale.x = scale.y = scale.z = Math.random() * 1;
matrix.compose( position, quaternion, scale );
};
}();
function initMesh() {
clean();
// make instances
new THREE.BufferGeometryLoader()
.setPath( 'uploads/threejs/' )
.load( 'suzanne_buffergeometry.json', function ( geometry ) {
material = new THREE.MeshNormalMaterial();
geometry.computeVertexNormals();
console.time( api.method + ' (build)' );
switch ( api.method ) {
case Method.INSTANCED:
makeInstanced( geometry );
break;
case Method.MERGED:
makeMerged( geometry );
break;
case Method.NAIVE:
makeNaive( geometry );
break;
}
console.timeEnd( api.method + ' (build)' );
} );
}
function makeInstanced( geometry ) {
const matrix = new THREE.Matrix4();
const mesh = new THREE.InstancedMesh( geometry, material, api.count );
for ( let i = 0; i < api.count; i ++ ) {
randomizeMatrix( matrix );
mesh.setMatrixAt( i, matrix );
}
scene.add( mesh );
//
const geometryByteLength = getGeometryByteLength( geometry );
guiStatsEl.innerHTML = [
'<i>GPU draw calls</i>: 1',
'<i>GPU memory</i>: ' + formatBytes( api.count * 16 + geometryByteLength, 2 )
].join( '<br/>' );
}
function makeMerged( geometry ) {
const geometries = [];
const matrix = new THREE.Matrix4();
for ( let i = 0; i < api.count; i ++ ) {
randomizeMatrix( matrix );
const instanceGeometry = geometry.clone();
instanceGeometry.applyMatrix4( matrix );
geometries.push( instanceGeometry );
}
const mergedGeometry = BufferGeometryUtils.mergeBufferGeometries( geometries );
scene.add( new THREE.Mesh( mergedGeometry, material ) );
//
guiStatsEl.innerHTML = [
'<i>GPU draw calls</i>: 1',
'<i>GPU memory</i>: ' + formatBytes( getGeometryByteLength( mergedGeometry ), 2 )
].join( '<br/>' );
}
function makeNaive( geometry ) {
const matrix = new THREE.Matrix4();
for ( let i = 0; i < api.count; i ++ ) {
randomizeMatrix( matrix );
const mesh = new THREE.Mesh( geometry, material );
mesh.applyMatrix4( matrix );
scene.add( mesh );
}
//
const geometryByteLength = getGeometryByteLength( geometry );
guiStatsEl.innerHTML = [
'<i>GPU draw calls</i>: ' + api.count,
'<i>GPU memory</i>: ' + formatBytes( api.count * 16 + geometryByteLength, 2 )
].join( '<br/>' );
}
function init() {
const width = window.innerWidth;
const height = window.innerHeight;
// camera
camera = new THREE.PerspectiveCamera( 70, width / height, 1, 100 );
camera.position.z = 30;
// renderer
renderer = new THREE.WebGLRenderer( { antialias: true } );
renderer.setPixelRatio( window.devicePixelRatio );
renderer.setSize( width, height );
renderer.outputEncoding = THREE.sRGBEncoding;
container = document.getElementById( 'container' );
container.appendChild( renderer.domElement );
// scene
scene = new THREE.Scene();
scene.background = new THREE.Color( 0xffffff );
// controls
controls = new OrbitControls( camera, renderer.domElement );
controls.autoRotate = true;
// stats
stats = new Stats();
container.appendChild( stats.dom );
// gui
gui = new GUI();
gui.add( api, 'method', Method ).onChange( initMesh );
gui.add( api, 'count', 1, 10000 ).step( 1 ).onChange( initMesh );
const perfFolder = gui.addFolder( 'Performance' );
guiStatsEl = document.createElement( 'li' );
guiStatsEl.classList.add( 'gui-stats' );
perfFolder.__ul.appendChild( guiStatsEl );
perfFolder.open();
// listeners
window.addEventListener( 'resize', onWindowResize );
Object.assign( window, { scene } );
}
//
function onWindowResize() {
const width = window.innerWidth;
const height = window.innerHeight;
camera.aspect = width / height;
camera.updateProjectionMatrix();
renderer.setSize( width, height );
}
function animate() {
requestAnimationFrame( animate );
controls.update();
stats.update();
render();
}
function render() {
renderer.render( scene, camera );
}
//
function getGeometryByteLength( geometry ) {
let total = 0;
if ( geometry.index ) total += geometry.index.array.byteLength;
for ( const name in geometry.attributes ) {
total += geometry.attributes[ name ].array.byteLength;
}
return total;
}
// Source: https://stackoverflow.com/a/18650828/1314762
function formatBytes( bytes, decimals ) {
if ( bytes === 0 ) return '0 bytes';
const k = 1024;
const dm = decimals < 0 ? 0 : decimals;
const sizes = [ 'bytes', 'KB', 'MB' ];
const i = Math.floor( Math.log( bytes ) / Math.log( k ) );
return parseFloat( ( bytes / Math.pow( k, i ) ).toFixed( dm ) ) + ' ' + sizes[ i ];
}