public void LoadBxlyt(BxlytHeader header, string fileName)
        {
            LayoutFiles.Add(header);
            ActiveLayout = header;

            LayoutViewer Viewport = new LayoutViewer(header, Textures);

            Viewport.Dock = DockStyle.Fill;
            Viewport.Show(dockPanel1, DockState.Document);
            Viewport.DockHandler.AllowEndUserDocking = false;
            Viewports.Add(Viewport);
            ActiveViewport          = Viewport;
            ActiveViewport.UseOrtho = orthographicViewToolStripMenuItem.Checked;

            if (!isLoaded)
            {
                InitializeDockPanels();
            }

            isLoaded = true;
        }