@script ExecuteInEditMode
  @script RequireComponent(Camera)
  
  var fullOverdraw = false;
  var shaderWithZ : Shader;
  var shaderWithoutZ : Shader;
  
  private var oldColor : Color;
  private var oldClear : CameraClearFlags;
  
  function OnPreCull()
  {
          if (!enabled)
                  return;
          oldColor = camera.backgroundColor;
          oldClear = camera.clearFlags;
          camera.backgroundColor = Color(0,0,0,0);
          camera.clearFlags = CameraClearFlags.SolidColor;
          camera.SetReplacementShader (fullOverdraw ? shaderWithoutZ : shaderWithZ, "RenderType");
  }
  
  function OnPostRender() {
          if (!enabled)
                  return;
          camera.ResetReplacementShader();
          camera.backgroundColor = oldColor;
          camera.clearFlags = oldClear;
  }