Cameras do not work during Transition scene

[ivcoder]

Any nodes that have non-default camera are invisible during transition.

How to reproduce. Open HelloWorld project. Replace code inside HelloWorld::menuCloseCallback(Ref* pSender) with followed code:

    auto screenSize = Director::getInstance()->getVisibleSize();
    float zeye = Director::getInstance()->getZEye();
    auto camera = Camera::createPerspective(60, (GLfloat)screenSize.width/screenSize.height, 10, zeye + screenSize.height / 2.0f);
    // set parameters for camera
    Vec3 eye(screenSize.width/2, screenSize.height/2.0f, zeye);
    Vec3 center3D(screenSize.width/2, screenSize.height/2, 0.0f);
    Vec3 up(0.0f, 1.0f, 0.0f);
    //the calling order matters, we should first call setPosition3D, then call lookAt.
    camera->setPosition3D(eye);
    camera->lookAt(center3D, up);
    camera->setCameraFlag(CameraFlag::USER2);
    this->setCameraMask((unsigned short)CameraFlag::USER2, true);
    this->addChild(camera); //add camera to the scene



    Scene *scene = HelloWorld::createScene();
    // run
    Director::getInstance()->replaceScene(TransitionMoveInL::create(5.45f, scene));

Tap close button. Transition animation will start and current scene will immediately become invisible.

The same happens with the TransitionScene self when we add camera to it (If I want to make my own custom transition derived from TransitionScene).
Bug takes place because render() method of the scenes is not executed during transitions.

[Guy-kun]

I have to revive this due to this being still a huge hassle in 3.10

Two issues are occurring in my case:

1. As above, non-default cameras are not rendered during the transition, CCTransition only calls visit() and not render() on the old scene, meaning it's cameras are not visited
2. During the transition, CCTransition's call to visit() inside draw() result in the DEFAULT camera being drawn over everything, including the transition itself due to the forementioned call to visit() instead of render() (I'm not sure why this happens in detail)

I solved this by subclassing CCTransition and changing the render and draw methods to the below:

void TransitionShutter::draw(Renderer *renderer, const Mat4 &transform, uint32_t flags)
{
    // Do not call parent, it is broken
    Scene::draw(renderer, transform, flags);
}

void TransitionShutter::render(Renderer* renderer)
{
    if (_outScene->isVisible())
        _outScene->render(renderer);
    if (_inScene->isVisible())
        _inScene->render(renderer);
    Scene::render(renderer);
}

and this seems to be a working 'botch' but I don't know the implications of this so can't commit it to the original CCTransition.

If anyone could take a look at the interaction between cameras and transitions it'd be appreciated.
(Cameras in general are an unbelievable nightmare at the moment coupled with global z orders, camera visit order, node hierarchy and batched rendering all disobeying each other)

[Guy-kun]

Just to add, I've realised this very likely happens due to depth test being enabled in the director

[Almax27]

This was an issue for me too, the above suggested fix does seem to work for most simple transitions but I don't have the time to test all of them.

[gestern]

Cocos2d-X 3.17 after 3 years the issue is still present. Any news with the issue? It's just affected too many people not to get involved in disclose the issue.

Cocos2d-X 3.17.1 I have the same problem. :/

[Xioor]

Same problem in cocos2d-x v4