Utilizar materiales interactivos en Papervision GreatWhite

package{

	import flash.display.*

	public class Materiales extends MovieClip{

		import flash.events.Event;

		import flash.text.*;

		import org.papervision3d.view.Viewport3D;

    	import org.papervision3d.cameras.Camera3D;

		import org.papervision3d.scenes.Scene3D;

		import org.papervision3d.render.BasicRenderEngine;

		import org.papervision3d.materials.*;

		import org.papervision3d.objects.primitives.Sphere;

		import org.papervision3d.events.InteractiveScene3DEvent;

		var escena:Scene3D;

		var renderer:BasicRenderEngine;

		var camara:Camera3D;

		var viewport:Viewport3D;

		var esfera:Sphere;

		public function Materiales(){

			crear3D();

			crearObjeto();

		}

		public function crear3D():void{

			escena = new Scene3D();

			renderer = new BasicRenderEngine();

			camara = new Camera3D();

			//El cuarto parámetro que paso en el constructor es para la propiedad interactive de viewPort. 

			//Si se van a utilizar eventos de ratón, hay que pasar 'true' (por defecto 'false')

			viewport = new Viewport3D(500,500,false,true);

			addChild(viewport);

			camara.z = -500;

			addEventListener(Event.ENTER_FRAME, renderizar);

		}

		public function crearObjeto():void{

			var material:MovieAssetMaterial = new MovieAssetMaterial("MaterialBiblioteca");

			//El material usado en el objeto interactivo debe tener interactive = true (por defecto 'false')

			material.interactive = true;

			esfera = new Sphere(material, 200, 10, 10);

			//Por último, se añaden los eventos

			esfera.addEventListener(InteractiveScene3DEvent.OBJECT_PRESS,esferaPresionada);

			esfera.addEventListener(InteractiveScene3DEvent.OBJECT_OVER,esferaOver);

			esfera.addEventListener(InteractiveScene3DEvent.OBJECT_OUT,esferaOut);

			escena.addChild(esfera);

		}

		private function esferaPresionada(e:InteractiveScene3DEvent):void{

			//La función recoge el parámetro e, que tiene el atributo displayObject3D;

			Texto_txt.text = "Click sobre la esfera " +  e.displayObject3D;

		}

		private function esferaOver(e:InteractiveScene3DEvent):void{

			Texto_txt.text = "Over sobre la esfera";

		}

		private function esferaOut(e:InteractiveScene3DEvent):void{

			Texto_txt.text = "Out sobre la esfera";

		}

		private function renderizar(e:Event):void{

			esfera.yaw(1);	

			renderer.renderScene(escena, camara, viewport);

		}

	}

}