back.z = camera.z + 1500

package {

	import flash.ui.Keyboard;
	import flash.events.*;
		
	import org.papervision3d.view.*;
	import org.papervision3d.materials.*;
	import org.papervision3d.objects.primitives.*;
	import org.papervision3d.scenes.Scene3D;
	import org.papervision3d.cameras.Camera3D;
	import org.papervision3d.render.BasicRenderEngine;
	
	import org.papervision3d.lights.*;
    　　 import org.papervision3d.materials.shaders.*;   

	import org.papervision3d.objects.special.ParticleField;
    　　　import org.papervision3d.materials.special.ParticleMaterial;

	public class Earthmove extends BasicView {
		private var light:PointLight3D;
		private var r:Number=0;
		var degrees_int:int=60;//角度
	
		public function Earthmove() {
			
              
			 super(stage.stageWidth, stage.stageHeight  , true, true );

			var centerx_int:int=0;//中心x座標(0がStage上中心)
			var centerz_int:int=0;//中心z座標
			var diameter_int:int=2000;//半径
			var speed_int:int=1;//毎回の移動角度
 
             //背景　＝ uchuu
            var material2:BitmapAssetMaterial=new BitmapAssetMaterial('back');
			var uchuu:Plane=new Plane(material2,15000,15000);
			uchuu.useOwnContainer=false;
									
			//星屑を追加
			var particleMat:ParticleMaterial = new ParticleMaterial(0xFFFFFF, 1)
            var particles:ParticleField = new ParticleField(particleMat, 5000, 4,  10000, 10000,10000);
		    //ライト設定
			light = new PointLight3D(true,false);
            light.z = 0;
            light.x =0;
            light.y = 0;

			//地球
			var material:BitmapAssetMaterial=new BitmapAssetMaterial('Earth');
			var shader = new FlatShader(light, 0xFFFFFF, 0x555555,0.5) ;
			var shadedMaterial = new ShadedMaterial(material, shader) 
			var sphere:Sphere=new Sphere(shadedMaterial,100,30,30);
			sphere.useOwnContainer=true;
					    
        			
			addEventListener(Event.ENTER_FRAME, function(d){  ;
																									

			sphere.x = Math.sin(degrees_int * Math.PI/180) * diameter_int + centerx_int;
			sphere.z = Math.cos(degrees_int * Math.PI/180) * diameter_int + centerz_int;
			degrees_int += speed_int;
			degrees_int %= 360;//360以上になった場合に0?へ戻す
			
//背景の位置　背景はカメラが動いても見た目の表示を変えたくない
		 uchuu.x = camera.x;
			uchuu.z = camera.z +15000;

//次の二行がわかりません。
uchuu.y =camera.y*(uchuu.z/-camera.z)*-1;
uchuu.rotationX =Math.atan2(-camera.z,camera.y);			
			
		}
		)
		scene.addChild(uchuu);
		scene.addChild(sphere);
		scene.addChild( particles );
		
		startRendering();

		// 球面を回転させる  

		addEventListener(Event.ENTER_FRAME, function(e){  ;
		sphere.rotationY += 4;
		
	}
	)
	camera.focus=500;
	camera.zoom=3;
	camera.x=0;
	camera.y=0;
	camera.z=-3000;
	if(camera.z >= 0){camera.z = 0};
	stage.addEventListener(KeyboardEvent.KEY_DOWN,keyboardDownEvent);

	startRendering();
}
//キーボードのKeyDownイベント処理
private function keyboardDownEvent(event:KeyboardEvent):void {
	switch (event.keyCode) {
		case 39 :
			//→キー
			camera.y+=100;
			break;
		case 37 :
			//←キー
			camera.y-=100;
			break;
		case 38 :
			//↑キー
			camera.z+=100;
			break;
		case 40 :
			//↓キー
			camera.z-=100;
			break;
				}
	}

}
}
 

var material2:BitmapAssetMaterial=new BitmapAssetMaterial('back');
			var uchuu:Plane=new Plane(material2,10000,10000);
			uchuu.useOwnContainer=true;


uchuu.x = 0;
			uchuu.y = 0;
			uchuu.z = 5000;

scene.addChild(uchuu);