title: Urho3d skynode unwanted artefacts
body: <p>I have a problem with a sky node in the UrhoSharp 1.4.47 sprite engine running on Android smartphones and tablets. iPhones don't have this problem.</p>
  
  <p>When looking at the sky node exactly in the direction up ={0,1,0} or left ={1,0,0} or right or back or front, the sprite engine shows a white unwanted Artefact. </p>
  
  <p><img src="https://i.stack.imgur.com/XLgAX.png" width="200"><img src="https://i.stack.imgur.com/vaEsg.png" width="200"> </p>
  
  <p>The sky node texture is a cube map, so the problem is when I look exactly at the normal of a face.</p>
  
  <pre><code>&lt;cubemap&gt;
  &lt;face name="BrightDay1_PosX.dds" /&gt;
  &lt;face name="BrightDay1_NegX.dds" /&gt;
  &lt;face name="BrightDay1_PosY.dds" /&gt;
  &lt;face name="BrightDay1_NegY.dds" /&gt;
  &lt;face name="BrightDay1_PosZ.dds" /&gt;
  &lt;face name="BrightDay1_NegZ.dds" /&gt;
  &lt;quality low="0" /&gt;
  &lt;/cubemap&gt;
  </code></pre>
  
  <p>The code is in a Xamarin Studio C# project.:</p>
  
  <pre><code>using Urho;
  namespace Play
  {
  public class Level2
  {
      public Level2() { }
      void CreateSky()
      {
          var cache = Application.Current.ResourceCache;
          Node skyNode = scene.CreateChild("Sky");
          skyNode.SetScale(500.0f); 
          Skybox skybox = skyNode.CreateComponent&lt;Skybox&gt;();
          skybox.Model = cache.GetModel("Models/Box.mdl");
          skybox.SetMaterial(cache.GetMaterial("Materials/Skybox.xml"));
  }
  }
  </code></pre>