add scene switch node

apps/openmw/mwrender/renderingmanager.cpp

@@ -205,7 +205,9 @@ namespace MWRender
         mSceneRoot = sceneRoot;
         sceneRoot->setStartLight(1);
 
-        mRootNode->addChild(sceneRoot);
+        mSceneSwitch = new osg::Switch;
+        mSceneSwitch->addChild(sceneRoot);
+        mRootNode->addChild(mSceneSwitch);
 
         mPathgrid.reset(new Pathgrid(mRootNode));
 
@@ -815,12 +817,15 @@ namespace MWRender
         // so out of order calls are necessary to get a correct frameNumber for the next frame.
         // refer to the advance() and frame() order in Engine::go()
 
+        mSceneSwitch->setAllChildrenOff();    // don't render the scene for main camera
+
         mViewer->eventTraversal();
         mViewer->updateTraversal();
         mViewer->renderingTraversals();
-
         callback->waitTillDone();
 
+        mSceneSwitch->setAllChildrenOn();
+
         mViewer->getCamera()->setClearMask(maskBackup);
         mViewer->getCamera()->setClearDepth(clearDepthBackup);
 

apps/openmw/mwrender/renderingmanager.hpp

@@ -224,6 +224,7 @@ namespace MWRender
         osg::ref_ptr<osgViewer::Viewer> mViewer;
         osg::ref_ptr<osg::Group> mRootNode;
         osg::ref_ptr<osg::Group> mSceneRoot;
+        osg::ref_ptr<osg::Switch> mSceneSwitch;
         Resource::ResourceSystem* mResourceSystem;
 
         osg::ref_ptr<SceneUtil::WorkQueue> mWorkQueue;