Do not activate a 3d view that already is active.

ApplicationLibCode/UserInterface/RiuPlotMainWindow.cpp

@@ -816,7 +816,7 @@ RimViewWindow* RiuPlotMainWindow::activeViewer()
 {
     for ( auto view : viewWindows() )
     {
-        if ( view->isActive() )
+        if ( view->isActiveViewer() )
         {
             return view;
         }

ApplicationLibCode/UserInterface/RiuViewer.cpp

@@ -727,8 +727,11 @@ void RiuViewer::mousePressEvent( QMouseEvent* mouseEvent )
 
         if ( auto ownView = ownerViewWindow() )
         {
-            ownView->setAsActiveViewer();
-            Riu3DMainWindowTools::selectAsCurrentItem( ownView );
+            if ( !ownView->isActiveViewer() )
+            {
+                ownView->setAsActiveViewer();
+                Riu3DMainWindowTools::selectAsCurrentItem( ownView );
+            }
         }
     }
 }