public void DrawSprites ( GameTime gameTime, StereoEye stereoEye, RenderTargetSurface surface, IEnumerable<SpriteLayer> layers )
{
device.ResetStates();
//device.RestoreBackbuffer();
device.SetTargets( null, surface );
DrawSpritesRecursive( gameTime, stereoEye, surface, layers, Matrix.Identity, new Color4(1f,1f,1f,1f) );
}