Chrome Experiment #1000

// Chrome Experiments #1000 Editor!
// Write your own particle behavior and share the code with your URL.
// Press Command + E to evaluate your changes.

var spacing = 15, size = 10;

var center = new THREE.Vector3( 1, 1, 1 );
center.multiplyScalar( Math.floor( size / 2 ) );

return {

init: function( particle, i ) {

var x = particle.index % size;
        var y = Math.floor( particle.index / size ) % size;
        var z = Math.floor( particle.index / ( size * size ) );

particle.position.set( x, y, z );
        particle.position.sub( center );
        particle.position.multiplyScalar( spacing );

particle.originalPosition = new THREE.Vector3().copy( particle.position );

update: function( particle, currentTime ) {

var x = particle.index % size;
        var y = Math.floor( particle.index / size ) % size;
        var z = Math.floor( particle.index / ( size * size ) );

var scale = Math.max( 0, Math.sin( -currentTime + 0.25 * ( x + y + z )  ) );

particle.position.copy( particle.originalPosition );
        particle.position.y += Math.sin( currentTime + x ) * 4;
        particle.scale.set( scale, scale, scale );

}