diff --git a/website/o3dv/js/navigator.js b/website/o3dv/js/navigator.js
index 7f2899c..d0052bd 100644
--- a/website/o3dv/js/navigator.js
+++ b/website/o3dv/js/navigator.js
@@ -57,16 +57,24 @@ OV.Navigator = class
     {
         this.callbacks = callbacks;
 
+        this.panelSet.Init ({
+            onResize : () => {
+                this.callbacks.onResize ();
+            }
+        });
+
         this.filesPanel.Init ({
             onFileBrowseButtonClicked : () => {
                 this.callbacks.openFileBrowserDialog ();
             }
         });
+
         this.materialsPanel.Init ({
             onMaterialSelected : (materialIndex) => {
                 this.SetSelection (new OV.Selection (OV.SelectionType.Material, materialIndex));
             }
         });
+
         this.meshesPanel.Init ({
             onMeshSelected : (meshId) => {
                 this.SetSelection (new OV.Selection (OV.SelectionType.Mesh, meshId));
diff --git a/website/o3dv/js/panelset.js b/website/o3dv/js/panelset.js
index 6e90b12..d9d384f 100644
--- a/website/o3dv/js/panelset.js
+++ b/website/o3dv/js/panelset.js
@@ -24,6 +24,10 @@ OV.Panel = class
 
     Show (show)
     {
+        if (this.visible === show) {
+            return;
+        }
+
         this.visible = show;
         if (this.visible) {
             this.panelDiv.show ();
@@ -51,6 +55,13 @@ OV.PanelSet = class
         this.menuDiv = $('<div>').addClass ('ov_panel_set_menu').appendTo (parentDiv);
         this.contentDiv = $('<div>').addClass ('ov_panel_set_content').appendTo (parentDiv);
         this.panels = [];
+        this.panelsVisible = true;
+        this.callbacks = null;
+    }
+
+    Init (callbacks)
+    {
+        this.callbacks = callbacks;
     }
 
     GetContentDiv ()
@@ -63,10 +74,30 @@ OV.PanelSet = class
         this.panels.push (panel);
         let button = OV.AddSvgIcon (this.menuDiv, panel.GetIcon (), 'ov_panel_set_menu_button');
         button.click (() => {
-            this.ShowPanel (panel);
+            if (panel === this.GetVisiblePanel ()) {
+                //this.ShowPanels (false);
+            } else {
+                //this.ShowPanels (true);
+                this.ShowPanel (panel);
+            }
         });
     }
 
+    ShowPanels (show)
+    {
+        if (this.panelsVisible === show) {
+            return;
+        }
+
+        this.panelsVisible = show;
+        if (this.panelsVisible) {
+            this.contentDiv.show ();
+        } else {
+            this.contentDiv.hide ();
+            this.callbacks.onResize ();
+        }
+    }
+
     ShowPanel (panel)
     {
         if (panel === this.GetVisiblePanel ()) {
@@ -81,6 +112,9 @@ OV.PanelSet = class
 
     GetVisiblePanel ()
     {
+        if (!this.panelsVisible) {
+            return null;
+        }
         for (let panel of this.panels) {
             if (panel.IsVisible ()) {
                 return panel;