three.js/src/objects/ParticleSystem.js

/**
 * @author alteredq / http://alteredqualia.com/
 */

THREE.ParticleSystem = function ( geometry, material ) {

	THREE.Object3D.call( this );

	this.geometry = geometry;
	this.material = material;

	this.sortParticles = false;

	if ( this.geometry ) {

		// calc bound radius

		if( !this.geometry.boundingSphere ) {

			this.geometry.computeBoundingSphere();

		}

		this.boundRadius = geometry.boundingSphere.radius;

	}

	this.frustumCulled = false;

};

THREE.ParticleSystem.prototype = new THREE.Object3D();
THREE.ParticleSystem.prototype.constructor = THREE.ParticleSystem;