Disable shaders for the sky

apps/openmw/mwrender/sky.cpp

@@ -1125,6 +1125,9 @@ SkyManager::SkyManager(osg::Group* parentNode, Resource::SceneManager* sceneMana
     , mSunEnabled(true)
 {
     osg::ref_ptr<CameraRelativeTransform> skyroot (new CameraRelativeTransform);
+    // Assign empty program to specify we don't want shaders
+    // The shaders generated by the SceneManager can't handle everything we need
+    skyroot->getOrCreateStateSet()->setAttributeAndModes(new osg::Program(), osg::StateAttribute::OVERRIDE);
 
     skyroot->setNodeMask(Mask_Sky);
     parentNode->addChild(skyroot);