Unhandled exception using Qt53DRenderd.dll in VC 2013 proj

[Poorti]

Hi All,

I am a newbie in Qt. Currently using Qt5.6 and VC 2013 on Win7.
I came across a sample in qt3d that uses the assimp lib (assimp-cpp). I tried that on QtCreator and it ran without issues. However, when I tried to use the same code in my VC++ sample project, I encountered runtime exception on the execution of the following statement,

engine.setRootEntity(sceneRoot);

Please find a screenshot of the error attached here.

I am trying to use this snippet inside my Adobe Illustrator plugin.

After breaking the exception, I get this.

Can anyone guide me here?
Am I missing any dll references or something?

[VRonin]

We don't have much code to work on so this will just be a guess.

Is sceneRoot a non-null pointer to a valid object (i.e. created with new and not destroyed)?

[Poorti]

Thanks for replying!

This is the code,

	int argc = 0;
	QApplication* _Application = static_cast<QApplication *>(QApplication::instance());
	_Application = new QApplication(argc, 0, true);

	view = new Window(); // view is a global object of Window type.
	view->setPosition(10, 100);
	Qt3DCore::QAspectEngine engine;
	Qt3DInput::QInputAspect *inputAspect = new Qt3DInput::QInputAspect();
	engine.registerAspect(new Qt3DRender::QRenderAspect());
	engine.registerAspect(inputAspect);
	QVariantMap data;
	data.insert(QStringLiteral("surface"), QVariant::fromValue(static_cast<QSurface *>(view)));
	data.insert(QStringLiteral("eventSource"), QVariant::fromValue(view));
	engine.setData(data);

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

	//// Scene Camera
	Qt3DCore::QCamera *basicCamera = new Qt3DCore::QCamera(sceneRoot);
	basicCamera->setProjectionType(Qt3DCore::QCameraLens::PerspectiveProjection);
	basicCamera->setAspectRatio(view->width() / view->height());
	basicCamera->setUpVector(QVector3D(0.0f, 1.0f, 0.0f));
	basicCamera->setViewCenter(QVector3D(0.0f, 3.5f, 0.0f));
	basicCamera->setPosition(QVector3D(0.0f, 3.5f, 25.0f));
	basicCamera->setNearPlane(0.001f);
	basicCamera->setFarPlane(10000.0f);
	// For camera controls
	inputAspect->setCamera(basicCamera);

	//// Forward Renderer FrameGraph
	Qt3DRender::QFrameGraph *frameGraphComponent = new Qt3DRender::QFrameGraph(sceneRoot);
	Qt3DRender::QForwardRenderer *forwardRenderer = new Qt3DRender::QForwardRenderer();
	forwardRenderer->setCamera(basicCamera);
	forwardRenderer->setClearColor(Qt::black);
	frameGraphComponent->setActiveFrameGraph(forwardRenderer);
	sceneRoot->addComponent(frameGraphComponent);

	// Scene loader
	Qt3DCore::QEntity *sceneLoaderEntity = new Qt3DCore::QEntity(sceneRoot);
	Qt3DRender::QSceneLoader *sceneLoader = new Qt3DRender::QSceneLoader(sceneLoaderEntity);
	SceneWalker sceneWalker(sceneLoader);
	QObject::connect(sceneLoader, &Qt3DRender::QSceneLoader::statusChanged, &sceneWalker, &SceneWalker::onStatusChanged);
	sceneLoaderEntity->addComponent(sceneLoader);

	std::string url = GetURL();

	QString source = "file:///";
	source.append(url.c_str());   // This gives us a url to a local file eg, file:///C:/work/qt/model.dae

	QUrl sourceFileName = source;
	if (sourceFileName.isEmpty())
		return 0;

	sceneLoader->setSource(sourceFileName);

	engine.setRootEntity(sceneRoot);

	view->show();

Looks like sceneRoot is a non-null pointer to a valid object.

[VRonin]

• You are leaking memory like a bandit
• The QApplication constructor is invalid, please see the warning here: http://doc.qt.io/qt-5/qapplication.html#QApplication
  replace

 int argc = 0;
    QApplication* _Application = static_cast<QApplication *>(QApplication::instance());
    _Application = new QApplication(argc, 0, true);

with

 char  arg0[] = "programName";
    char* argv[] = { &arg0[0], NULL };
    int   argc = (int)(sizeof(argv) / sizeof(argv[0])) - 1;
    QApplication the_application(argc, &argv[0]);

[Poorti]

Thanks for pointing that out VRonin!

I updated the code as pointed out.
Can you guide me on that exception please?

[Neosw]

I think that sceneRoot must be not the parent of the frame graph.
You have forgot to set a rendering surface.
The FrameGraph root node must be a QRenderSettings

  //// Forward Renderer FrameGraph
    Qt3DRender::QFrameGraph *frameGraphComponent = new Qt3DRender::QFrameGraph(sceneRoot);
    Qt3DRender::QForwardRenderer *forwardRenderer = new Qt3DRender::QForwardRenderer();
    forwardRenderer->setCamera(basicCamera);
    forwardRenderer->setClearColor(Qt::black);
    frameGraphComponent->setActiveFrameGraph(forwardRenderer);
    sceneRoot->addComponent(frameGraphComponent);

to:

      //// Forward Renderer FrameGraph
    Qt3DRender::QRenderSettings *frameGraphComponent = new Qt3DRender::QRenderSettings(); //not set the parent
    Qt3DRender::QForwardRenderer *forwardRenderer = new Qt3DRender::QForwardRenderer();
    forwardRenderer->setCamera(basicCamera);
    forwardRenderer->setClearColor(Qt::black);
    forwardRenderer->surface(view); //add a surface for the rendering loop
    frameGraphComponent->setActiveFrameGraph(forwardRenderer);
    sceneRoot->addComponent(frameGraphComponent);

There are me be a mistake when you set the root entity.
In the Qt3DWindow the root entity is set like follow:

157	void Qt3DWindow::showEvent(QShowEvent *e)
158	{
159	    if (!m_initialized) {
160	        if (m_userRoot != nullptr)
161	            m_userRoot->setParent(m_root);
162	
163	        m_root->addComponent(m_renderSettings);
164	        m_root->addComponent(m_inputSettings);
165	        m_aspectEngine->setRootEntity(Qt3DCore::QEntityPtr(m_root));
166	
167	        m_initialized = true;
168	    }
169	
170	    QWindow::showEvent(e);
171	}

https://code.woboq.org/qt5/qt3d/src/extras/defaults/qt3dwindow.cpp.html

Me be change you code to:

    engine.setRootEntity(Qt3DCore::QEntityPtr(sceneRoot));

[Poorti]

@Neosw
Thanks a lot!!
It seems there was some kind of bug in Qt5.6 which stopped the model from rendering.
I updated to Qt5.7 and it worked!
:)