Back of 3d model appears transparent in qt 5.7

[Poorti]

Hi All!

I have created a sample to load 3d models. I am able to load the model.
However, when I rotate the model, the back appears to be transparent and dark.
How do I fix this?

Here is the code,

int main(int ac, char **av)
{
    QApplication app(ac, av);
    Qt3DExtras::Qt3DWindow view;
    view.defaultFramegraph()->setClearColor(QColor("#9E9D9D"));

    // Root entity
    Qt3DCore::QEntity *sceneRoot = new Qt3DCore::QEntity();

    // Scene Camera
    Qt3DRender::QCamera *camera = view.camera();
    camera->setProjectionType(Qt3DRender::QCameraLens::PerspectiveProjection);
    camera->setAspectRatio(view.width() / view.height());
    camera->setUpVector(QVector3D(0.0f, 1.0f, 0.0f));
    camera->setViewCenter(QVector3D(0.04f, 1.0f, 0.0f));
    camera->setPosition(QVector3D(0.0f, 2.5f, 2.1f));
    camera->setNearPlane(0.001f);
    camera->setFarPlane(100.0f);

    // For camera controls
    Qt3DExtras::QOrbitCameraController *camController = new Qt3DExtras::QOrbitCameraController(sceneRoot);
    camController->setCamera(camera);

    // Scene loader
    Qt3DCore::QEntity *sceneLoaderEntity = new Qt3DCore::QEntity(sceneRoot);
    Qt3DRender::QSceneLoader *sceneLoader = new Qt3DRender::QSceneLoader(sceneLoaderEntity);
    Qt3DRender::QDirectionalLight *light = new Qt3DRender::QDirectionalLight();
    light->setColor(Qt::white);
    light->setIntensity(1.0f);
    light->setWorldDirection(QVector3D(0.0f, -0.5f, -1.0f));
    SceneWalker sceneWalker(sceneLoader);
    QObject::connect(sceneLoader, &Qt3DRender::QSceneLoader::statusChanged, &sceneWalker, &SceneWalker::onStatusChanged);
    sceneLoaderEntity->addComponent(sceneLoader);
    sceneLoaderEntity->addComponent(light);

    QStringList args = QCoreApplication::arguments();
    QUrl sourceFileName;
    if (args.count() <= 1) {
        QWidget *container = new QWidget();
        QFileDialog dialog;
        dialog.setFileMode(QFileDialog::AnyFile);
        sourceFileName = dialog.getOpenFileUrl(container, QStringLiteral("Open a scene file"));
    } else {
        sourceFileName = QUrl::fromLocalFile(args[1]);
    }

    if (sourceFileName.isEmpty())
        return 0;

    sceneLoader->setSource(sourceFileName);

    view.setRootEntity(sceneRoot);
    view.show();

    return app.exec();
}

I am using qt 5.7 on windows. I have followed assimp-cpp sample of qt.