[away3d] Developing a planetarium. Problems with specular reflection

[Jon]

Hi all,
I'm devoloping a planetarium and space simulator in as3. It has its own
3d math library, but for planet rendering I'm using away3d.

I've uploaded some screenshots here:

http://www.betaeridani.com/gallery/

Some images show  planets in a double star system so they have an
unusual look :-)

And now my problem:

The screenshot 
http://www.betaeridani.com/gallery/_specular_bad_reflection.jpg
shows the problem I'm having with specular reflections. The  reflection
of the sun appears displaced to the left where it should be.

I've written a simple small Test class that replicates the problem above:
There is a  blue sphere that represents the Earth and a  yellow one that
represents the Sun.
There's also a light source located at the same coordinates as the Sun.

The reflection is correct as long as the x, y coordinates of the Planet
and the camera are equal
(http://www.betaeridani.com/gallery/_specular1.jpg)
but when you move the Planet or the camera and coordinates  are no
longer equal, I get a wrong reflection
(http://www.betaeridani.com/gallery/_specular2.jpg) .

Am I missing something here?



package com.jon.test {

import away3d.cameras.Camera3D;
import away3d.containers.Scene3D;
import away3d.containers.View3D;
import away3d.core.render.Renderer;
import away3d.lights.DirectionalLight3D;
import away3d.materials.ColorMaterial;
import away3d.materials.PhongColorMaterial;
import away3d.primitives.Sphere;

import flash.display.Sprite;

public class Test1 extends Sprite{

   private var _scene:Scene3D;
   private var _camera:Camera3D;
   private var _view:View3D;
   private var _planet:Sphere;
   private var _star:Sphere;
   private var _light:DirectionalLight3D;
   private var _planetMaterial:PhongColorMaterial;
   private var _starMaterial:ColorMaterial;

   public function Test1() {
   }

   public function init():void {
       init3d();
       createScene();
       setTestCoordinates();
   }

   private function init3d():void {
       _scene = new Scene3D();
       _camera = new Camera3D({zoom:30});
       _view = new View3D({
           scene:_scene,
           camera:_camera,
           renderer:Renderer.BASIC
       });
       addChild(_view);
   }

   private function createScene():void {

       _planetMaterial = new PhongColorMaterial(0x0000ff);
       _starMaterial = new ColorMaterial(0xffff00);
       _planetMaterial.shininess = 20;

       _planet = new Sphere({material:_planetMaterial, radius:6378,
segmentsW:30, segmentsH:30});
       _star = new Sphere({material:_starMaterial, radius:697000,
segmentsW:20, segmentsH:20});
       _light = new DirectionalLight3D({color:0xffffff, ambient:.3,
diffuse:2, specular:.8});

       //add objets to scene
       _scene.addChild(_planet);
       _scene.addChild(_star);
       _scene.addChild(_light);
   }

   private function setTestCoordinates():void {

       //planet coordinates
       _planet.x = 0;
       _planet.y = 4000;
       _planet.z = 0;

       //star coordinates
       setStarCoordinates(15267000, 4565000, 148192000);

       //camera coordinates
       _camera.x = 0;
       _camera.y = 0;
       _camera.z = -95000;

       //render
       _view.render();
   }

   private function setStarCoordinates(x:int, y:int, z:int):void {

       //light
       _light.x = x;
       _light.y = y;
       _light.z = z;

       //star coordinates = light coordinates
       _star.x = x;
       _star.y = y;
       _star.z = z;
   }

}
}