I'm not an expert in the field. Maybe this example code can help you: https://qt.gitorious.org/qt/qtdeclarative/source/15e58df3386b5438f6ae114a51ad4a258085e70b:examples/quick/scenegraph/shared/logorenderer.cpp
The whole example can be found here: http://doc.qt.io/qt-5/qtquick-scenegraph-textureinthread-example.html