It should be supported indeed. Did you try with a more recent release of Qt ? Like 5.15 or even 6.2 ?

@__dalin__ said in How to setup QOpenGLWindow to have access to desirable functionality?:

Run part of the project panel

In QtCreator click on Projects on the right side, then "Build & Run/Run".
"and in the system variable do we literally type "QT_OPENGL=desktop" in the field for the path" - there is no path. You simply add a new variable there (by clicking on Add button), change the Variable name to QT_OPENGL and Value to desktop, that's all.

QSurfaceFormat fmt(this->format()); cout << fmt.majorVersion() << "." << fmt.minorVersion() << endl;

Z-fighting is a completely different issue from aliasing. Maybe you need to set/check/increase the QSurfaceFormat::depthSize property (I've no idea what the default is).

If your z-buffer precision is as good as it can be, glPolygonOffset and/or controlling draw-order are next lines of defence against z-fighting.

I seem to remember the old forum allowed image upload; but maybe I'm thinking of the Jira (bugtracker). The markdown formatting here would let you link to a URL hosted elsewhere though (and maybe include it inline).