title: Unity Daydream distortion shader
body: <p>I'm working on a game for Google's daydream with the 'Pixel' phone. I'm looking for a way to play with the distortion shader, the one that renders each eyes to a <code>RenderTexture</code> in order to match the lenses distortion.</p>
  
  <p>I found the following code in <code>StereoRenderEffect.cs</code></p>
  
  <pre><code>using UnityEngine;
  
  /// @cond
  [RequireComponent(typeof(Camera))]
  [AddComponentMenu("GoogleVR/StereoRenderEffect")]
  public class StereoRenderEffect : MonoBehaviour {
  #if !UNITY_HAS_GOOGLEVR || UNITY_EDITOR
    private Material material;
  
    private Camera cam;
  
    private static readonly Rect fullRect = new Rect(0, 0, 1, 1);
  
    void Awake() {
      cam = GetComponent&lt;Camera&gt;();
    }
  
    void Start() {
      material = new Material(Shader.Find("GoogleVR/UnlitTexture"));
    }
  
    void OnRenderImage(RenderTexture source, RenderTexture dest) {
      GL.PushMatrix();
      int width = dest ? dest.width : Screen.width;
      int height = dest ? dest.height : Screen.height;
      GL.LoadPixelMatrix(0, width, height, 0);
      // Camera rects are in screen coordinates (bottom left is origin), but DrawTexture takes a
      // rect in GUI coordinates (top left is origin).
      Rect blitRect = cam.pixelRect;
      blitRect.y = height - blitRect.height - blitRect.y;
      RenderTexture oldActive = RenderTexture.active;
      RenderTexture.active = dest;
      Graphics.DrawTexture(blitRect, source, fullRect, 0, 0, 0, 0, Color.white, material);
      RenderTexture.active = oldActive;
      GL.PopMatrix();
    }
  #endif  // !UNITY_HAS_GOOGLEVR || UNITY_EDITOR
  }
  </code></pre>
  
  <p>It allowed me to find the <code>UnlitTexture.shader</code>, which is responsible for the distortion. <em>However</em> as the <code>#if !UNITY_HAS_GOOGLEVR || UNITY_EDITOR
  </code> implies, it only works when running it in the editor. I'm looking for a way to do the same when the app runs on the actual device, but can't find it. Does someone know where to look ?</p>