Papervision3D: understanding Plane object – part 5

package {
	import flash.display.Sprite;
	import flash.events.Event;
	import org.papervision3d.cameras.Camera3D;
	import org.papervision3d.render.BasicRenderEngine;
	import org.papervision3d.scenes.Scene3D;
	import org.papervision3d.view.Viewport3D;
	import org.papervision3d.objects.primitives.Plane;
	import org.papervision3d.materials.MovieMaterial;
	import org.papervision3d.events.InteractiveScene3DEvent;
	public class papervision extends Sprite {
		// this is the movieclip with the cards... currently it holds
		// only two cards... the back and the 10 of hearts
		public var my_card:card = new card();
		public var viewport:Viewport3D=new Viewport3D(500,400,false,true);
		public var scene:Scene3D = new Scene3D();
		public var camera:Camera3D = new Camera3D();
		public var renderer:BasicRenderEngine = new BasicRenderEngine();
		// now it's time to use Movie Materials... we can use a movieclip as a material
		public var front_material:MovieMaterial;
		public var back_material:MovieMaterial;
		public var front_plane:Plane;
		public var back_plane:Plane;
		public var rotation_speed=0;
		public var steps=0;
		public function papervision() {
			// going to frame 2
			my_card.gotoAndStop(2);
			// assigning the 2nd frame to front_material material
			front_material=new MovieMaterial(my_card);
			// going to frame 1...
			my_card.gotoAndStop(1);
			// and assign the 1st frame as material of the back_material material
			back_material=new MovieMaterial(my_card);
			front_plane=new Plane(front_material,200,250,4,5);
			back_plane=new Plane(back_material,200,250,4,5);
			addChild(viewport);
			camera.focus=100;
			camera.zoom=10;
			back_plane.rotationY=180;
			front_material.interactive=true;
			back_material.interactive=true;
			scene.addChild(front_plane);
			scene.addChild(back_plane);
			back_plane.addEventListener(InteractiveScene3DEvent.OBJECT_PRESS,on_plane_clicked);
			front_plane.addEventListener(InteractiveScene3DEvent.OBJECT_PRESS,on_plane_clicked);
			addEventListener(Event.ENTER_FRAME, render);
		}
		public function render(e:Event) {
			if (rotation_speed) {
				steps++;
				front_plane.yaw(rotation_speed);
				back_plane.yaw(rotation_speed);
			}
			if (steps==180/rotation_speed) {
				steps=0;
				rotation_speed=0;
			}
			renderer.renderScene(scene, camera, viewport);
		}
		public function on_plane_clicked(e:InteractiveScene3DEvent) {
			if (steps==0) {
				rotation_speed=4;
			}
		}
	}
}