Qt - multiple layers containing a QGraphicsView in one 3D scene (QGLWidget)

Question

I'm currently evaluating the possibilities to implement a navigable 3D scene which allows to render multiple 2D layers. To be a bit more precise, I would like to display multiple graphs in a 3D environment in order to pinpoint simularities and differences between those graphs. Considering the following screenshot, there would be two graphs (one black, one grey), which are equivalent - for different graphs, deviant nodes might, i.e, be highlighted in red.

I am working with Qt's Graphic View Framework and established an editable graph editor using QGraphicsScene and several QGraphicsItems, which I separately from this project.

Qt provides OpenGL support, e.g., the QGLWidget and I had a look at the provided examples. Given, that I have not worked with OpenGL (I did some work with Java3D though) I would love if some people can share their experience.

Several solutions came to my mind:

1. Render every QGraphicsView to a QPixmap and display them in 3D, which would make the graphs navigatable but would prohibit any picking of elements etc.
2. Create an equivalent 3D element for every 2D graph element and "transform" every QGraphicsView into an 3D representation. I guess this would be quite some work (espacially as I have not worked with OpenGL)
3. Maybe there is an easy way to "place" the QGraphicScenes, the view, or just the QGraphicsItems in a QGLWidget without many adaptions and still register the usual "mouseclickevents" etc.

For a first implementation a plain navigable "viewer" which displayes multiple graphs in different layers would sufficient. But I would like to keep it extendable in order to add, e.g., picking, in the future.

Answer 1

The Qt3D project provides a class called QGraphicsEmbedScene which does exactly what you are asking for.