Sprite.js

/**
 * @author mikael emtinger / http://gomo.se/
 * @author alteredq / http://alteredqualia.com/
 */

THREE.Sprite = function ( material ) {

	THREE.Object3D.call( this );

	this.type = 'Sprite';

	this.material = ( material !== undefined ) ? material : new THREE.SpriteMaterial();

};

THREE.Sprite.prototype = Object.create( THREE.Object3D.prototype );
THREE.Sprite.prototype.constructor = THREE.Sprite;

THREE.Sprite.prototype.raycast = ( function () {

	var matrixPosition = new THREE.Vector3();

	return function raycast( raycaster, intersects ) {

		matrixPosition.setFromMatrixPosition( this.matrixWorld );

		var distanceSq = raycaster.ray.distanceSqToPoint( matrixPosition );
		var guessSizeSq = this.scale.x * this.scale.y / 4;

		if ( distanceSq > guessSizeSq ) {

			return;

		}

		intersects.push( {

			distance: Math.sqrt( distanceSq ),
			point: this.position,
			face: null,
			object: this

		} );

	};

}() );

THREE.Sprite.prototype.clone = function () {

	return new this.constructor( this.material ).copy( this );

};