[Interest] [QT3D] access geometry data of a loaded model

[doe at john-online.info]

Hi

I use QT5.8 C++ API.
I know how to create and display models with vertex and index buffers.
How can I access data of a model loaded with Sceneloader() ?
I.e. I load an arbitrary model and afterwards want to read out the  
vertices, indices, materials etc. in order to
process this information.

Issue:
When I create my own models via my own buffers I have a hierarchy of  
entities & components which shows my creations (material/color,  
transformation, vertices, indices, textures)

Howevr, when I load an object like .obj or .ply, I always only see the  
url referrer to the source.
There is no entity tree other than the single child with the url apart  
from a trivial root node.
Is this intended or a bug? Can this be related to the OS/VM? (hardly  
imaginable though)


=> How can I access the actual object data?



Codewise i do the following:

              m_meshEntity = new Qt3DCore::QEntity();
              m_rootEntity = new Qt3DCore::QEntity();

              Qt3DRender::QSceneLoader *loader = new   
Qt3DRender::QSceneLoader(m_meshEntity);

              QString fileName = "../3dModels/someModel.obj";
              QUrl url = QUrl::fromLocalFile(fileName);

              QObject::connect(loader,  
&Qt3DRender::QSceneLoader::statusChanged,
                                       this,  
[](Qt3DRender::QSceneLoader::Status s){ qDebug() << s; return false;});


              loader->setSource(url);

              m_meshEntity->addComponent(loader);

              m_meshEntity->setParent(m_rootEntity);
              view->setRootEntity(m_rootEntity);
              view->show();

Then, m_meshEntity/m_rootEntity are trivial as described above. Its  
visible in the 3d window (view) but trivial from the "programmatical"  
content.