public void PrepareRenderItem(StorageBlock block) { var vp = _realVpGenerator.Next(block); _dispatcher.BeginInvoke( (GetRenderingItemDelegate)((viewport) => { _item = _pool.GetNextRenderingRealPointItem(); _item.RealViewport = viewport; _item.BeginRenderRealData(); _isCreated.Set(); }), vp ); }