Update CCScene.cpp

in line 157, here need to create  and add camera, if not ,in the function createWithPhysics, will show black screen.

cocos/2d/CCScene.cpp

@@ -153,6 +153,10 @@ bool Scene::initWithPhysics()
     {
         Director * director;
         CC_BREAK_IF( ! (director = Director::getInstance()) );
+        // add camera
+        auto camera = Camera::create();
+        addChild(camera);
+        
         this->setContentSize(director->getWinSize());
         CC_BREAK_IF(! (_physicsWorld = PhysicsWorld::construct(*this)));