private ImportedGeometry.UniqueIDType _currentModel; // Refer to the current geometry by ID to identify it on old and new level settings.

        public FormImportedGeometry(ImportedGeometryInstance instance, LevelSettings levelSettings)
        {
            InitializeComponent();
            _instance        = instance;
            _currentModel    = instance.Model?.UniqueID;
            OldLevelSettings = levelSettings;
            NewLevelSettings = levelSettings.Clone();
            importedGeometryManager.LevelSettings = NewLevelSettings;
            comboLightingModel.SelectedIndex      = (int)_instance.LightingModel;
            cbSharpEdges.Checked = _instance.SharpEdges;
            cbHide.Checked       = _instance.Hidden;

            // Set window property handlers
            Configuration.LoadWindowProperties(this, Editor.Instance.Configuration);
            FormClosing += new FormClosingEventHandler((s, e) => Configuration.SaveWindowProperties(this, Editor.Instance.Configuration));
        }