JAVASCRIPT
var Boid = function() {
var vector = new THREE.Vector3(),
_acceleration, _width = 900, _height = 900, _depth = 1600, _goal, _neighborhoodRadius = 800,
_maxSpeed = 1, _maxSteerForce = 0.1, _avoidWalls = false;
this.position = new THREE.Vector3();
this.velocity = new THREE.Vector3();
_acceleration = new THREE.Vector3();
this.setGoal = function ( target ) {
_goal = target;
}
this.setAvoidWalls = function ( value ) {
_avoidWalls = value;
}
this.setWorldSize = function ( width, height, depth ) {
_width = width;
_height = height;
_depth = depth;
}
this.run = function ( boids ) {
if ( _avoidWalls ) {
vector.set( - _width, this.position.y, this.position.z );
vector = this.avoid( vector );
vector.multiplyScalar( 19 );
_acceleration.add( vector );
vector.set( _width, this.position.y, this.position.z );
vector = this.avoid( vector );
vector.multiplyScalar( 19 );
_acceleration.add( vector );
vector.set( this.position.x, - _height, this.position.z );
vector = this.avoid( vector );
vector.multiplyScalar( 19 );
_acceleration.add( vector );
vector.set( this.position.x, _height, this.position.z );
vector = this.avoid( vector );
vector.multiplyScalar( 19 );
_acceleration.add( vector );
vector.set( this.position.x, this.position.y, - _depth );
vector = this.avoid( vector );
vector.multiplyScalar( 15 );
_acceleration.add( vector );
vector.set( this.position.x, this.position.y, _depth );
vector = this.avoid( vector );
vector.multiplyScalar( 5 );
_acceleration.add( vector );
}/* else {
this.checkBounds();
}
*/
if ( Math.random() > 0.5 ) {
this.flock( boids );
}
this.move();
}
this.flock = function ( boids ) {
if ( _goal ) {
_acceleration.add( this.reach( _goal, 0.9 ) );
}
_acceleration.add( this.alignment( boids ) );
_acceleration.add( this.cohesion( boids ) );
_acceleration.add( this.separation( boids ) );
}
this.move = function () {
this.velocity.add( _acceleration );
var l = this.velocity.length();
if ( l > _maxSpeed ) {
this.velocity.divideScalar( l / _maxSpeed );
}
this.position.add( this.velocity );
_acceleration.set( 0, 0, 0 );
}
this.checkBounds = function () {
if ( this.position.x > _width ) this.position.x = - _width;
if ( this.position.x < - _width ) this.position.x = _width;
if ( this.position.y > _height ) this.position.y = - _height;
if ( this.position.y < - _height ) this.position.y = _height;
if ( this.position.z > _depth ) this.position.z = - _depth;
if ( this.position.z < - _depth ) this.position.z = _depth;
}
//
this.avoid = function ( target ) {
var steer = new THREE.Vector3();
steer.copy( this.position );
steer.sub( target );
steer.multiplyScalar( 1 / this.position.distanceToSquared( target ) );
return steer;
}
this.repulse = function ( target ) {
var distance = this.position.distanceTo( target );
if ( distance < 200 ) {
var steer = new THREE.Vector3();
steer.subVectors( this.position, target );
steer.multiplyScalar( 0.9 / distance );
_acceleration.add( steer );
}
}
this.reach = function ( target, amount ) {
var steer = new THREE.Vector3();
steer.subVectors( target, this.position );
steer.multiplyScalar( amount );
return steer;
}
this.alignment = function ( boids ) {
var boid, velSum = new THREE.Vector3(),
count = 0;
for ( var i = 0, il = boids.length; i < il; i++ ) {
if ( Math.random() > 0.5 ) continue;
boid = boids[ i ];
distance = boid.position.distanceTo( this.position );
if ( distance > 0 && distance <= _neighborhoodRadius ) {
velSum.add( boid.velocity );
count++;
}
}
if ( count > 0 ) {
velSum.divideScalar( count );
var l = velSum.length();
if ( l > _maxSteerForce ) {
velSum.divideScalar( l / _maxSteerForce );
}
}
return velSum;
}
this.cohesion = function ( boids ) {
var boid, distance,
posSum = new THREE.Vector3(),
steer = new THREE.Vector3(),
count = 0;
for ( var i = 0, il = boids.length; i < il; i ++ ) {
if ( Math.random() > 0.5 ) continue;
boid = boids[ i ];
distance = boid.position.distanceTo( this.position );
if ( distance > 0 && distance <= _neighborhoodRadius ) {
posSum.add( boid.position );
count++;
}
}
if ( count > 0 ) {
posSum.divideScalar( count );
}
steer.subVectors( posSum, this.position );
var l = steer.length();
if ( l > _maxSteerForce ) {
steer.divideScalar( l / _maxSteerForce );
}
return steer;
}
this.separation = function ( boids ) {
var boid, distance,
posSum = new THREE.Vector3(),
repulse = new THREE.Vector3();
for ( var i = 0, il = boids.length; i < il; i ++ ) {
if ( Math.random() > 0.2 ) continue;
boid = boids[ i ];
distance = boid.position.distanceTo( this.position );
if ( distance > 0 && distance <= _neighborhoodRadius ) {
repulse.subVectors( this.position, boid.position );
repulse.normalize();
repulse.divideScalar( distance );
posSum.add( repulse );
}
}
return posSum;
}
}
var SCREEN_WIDTH = window.innerWidth,
SCREEN_HEIGHT = window.innerHeight,
SCREEN_WIDTH_HALF = SCREEN_WIDTH / 5,
SCREEN_HEIGHT_HALF = SCREEN_HEIGHT / 5;
var camera, scene, renderer,
birds, bird;
var boid, boids;
init();
animate();
function init() {
camera = new THREE.PerspectiveCamera( 75, SCREEN_WIDTH / SCREEN_HEIGHT, 1, 10000 );
camera.position.z = 450;
scene = new THREE.Scene();
birds = [];
boids = [];
for ( var i = 0; i < 190; i ++ ) {
boid = boids[ i ] = new Boid();
boid.position.x = Math.random() * 400 - 200;
boid.position.y = Math.random() * 400 - 200;
boid.position.z = Math.random() * 400 - 200;
boid.velocity.x = Math.random() * 2 - 1;
boid.velocity.y = Math.random() * 2 - 1;
boid.velocity.z = Math.random() * 2 - 1;
boid.setAvoidWalls( true );
boid.setWorldSize( 500, 500, 400 );
bird = birds[ i ] = new THREE.Mesh( new Bird(), new THREE.MeshBasicMaterial( { color:Math.random() * 0x388E3C, side: THREE.DoubleSide } ) );
bird.phase = Math.floor( Math.random() * 62.83 );
scene.add( bird );
}
renderer = new THREE.CanvasRenderer();
renderer.setClearColor( 0xfe8c00 );
renderer.setPixelRatio( window.devicePixelRatio );
renderer.setSize( SCREEN_WIDTH, SCREEN_HEIGHT );
document.addEventListener( 'mousemove', onDocumentMouseMove, false );
document.body.appendChild( renderer.domElement );
//
window.addEventListener( 'resize', onWindowResize, false );
}
function onWindowResize() {
camera.aspect = window.innerWidth / window.innerHeight;
camera.updateProjectionMatrix();
renderer.setSize( window.innerWidth, window.innerHeight );
}
function onDocumentMouseMove( event ) {
var vector = new THREE.Vector3( event.clientX - SCREEN_WIDTH_HALF, - event.clientY + SCREEN_HEIGHT_HALF, 0 );
for ( var i = 0, il = boids.length; i < il; i++ ) {
boid = boids[ i ];
vector.z = boid.position.z;
boid.repulse( vector );
}
}
//
function animate() {
requestAnimationFrame( animate );
render();
}
function render() {
for ( var i = 0, il = birds.length; i < il; i++ ) {
boid = boids[ i ];
boid.run( boids );
bird = birds[ i ];
bird.position.copy( boids[ i ].position );
color = bird.material.color;
color.r = color.g = color.b = ( 500 - bird.position.z ) / 1000;
bird.rotation.y = Math.atan2( - boid.velocity.z, boid.velocity.x );
bird.rotation.z = Math.asin( boid.velocity.y / boid.velocity.length() );
bird.phase = ( bird.phase + ( Math.max( 0, bird.rotation.z ) + 0.1 ) ) % 62.73;
bird.geometry.vertices[ 5 ].y = bird.geometry.vertices[ 4 ].y = Math.sin( bird.phase ) * 5;
}
renderer.render( scene, camera );
}
