three.js/src/renderers/DOMRenderer.js

/**
 * @author mr.doob / http://mrdoob.com/
 */

THREE.DOMRenderer = function () {

	THREE.Renderer.call( this );

	var _renderList = null,
	_projector = new THREE.Projector(),
	_div = document.createElement( 'div' ),
	_width, _height, _widthHalf, _heightHalf;

	this.domElement = _div;

	this.setSize = function ( width, height ) {

		_width = width; _height = height;
		_widthHalf = _width / 2; _heightHalf = _height / 2;

	};

	this.render = function ( scene, camera ) {

		var e, el, m, ml, element, material, dom, v1x, v1y;

		_renderList = _projector.projectScene( scene, camera );

		for ( e = 0, el = _renderList.length; e < el; e++ ) {

			element = _renderList[ e ];

			if ( element instanceof THREE.RenderableParticle ) {

				v1x = element.x * _widthHalf + _widthHalf; v1y = element.y * _heightHalf + _heightHalf;

				for ( m = 0, ml = element.material.length; m < ml; m++ ) {

					material = element.material[ m ];

					if ( material instanceof THREE.ParticleDOMMaterial ) {

						dom = material.domElement;
						dom.style.left = v1x + 'px';
						dom.style.top = v1y + 'px';

					}

				}

			}

		}

	};

}