For the purpouse of people who might search for an find this forum post, I put in a request with QT support and received the following.

Hi Joe,

Thank you for contacting Qt Support and for providing your sample project.

There are 2 broad ways to specify the fragmentShader property, depending on which version of Qt you want to target:

The Qt 5 way is to specify the shader's source code as a string. The Qt 6 way is to pre-compile your shader source code into a .qsb file, and specify a URL to that .qsb file

See:

https://doc.qt.io/qt-5/qml-qtquick-shadereffect.html#fragmentShader-prop https://doc.qt.io/qt-6/qml-qtquick-shadereffect.html#fragmentShader-prop

To do it the Qt 5 way, the easiest approach is to copy the contents of your .frag file and paste it as a string literal (surrounded by quotation marks) to the RHS of the "fragmentShader" property.

To do it the Qt 6 way, run the QSB tool to compile your shader source code. Unfortunately, the code of colour_wheel.frag is too old to be supported by QSB (for example, the "varying" keyword was deprecated long ago, and even removed for ES profiles)

See:

https://doc.qt.io/qt-6/qtshadertools-overview.html https://doc.qt.io/qt-6/qtshadertools-qsb.html

I hope this helps.

@SGaist Thank you, I will check it out.

Great. Just a hint: a map (as any other node-based structure) is not very performance friendly (traversal thrashes memory cache a lot). Try to structure your data so that it is accessed linearly whenever possible i.e. vector of models sorted by the shader is often better than a map.
I recommend this excellent talk from CppCon2014: Efficiency with Algorithms, Performance with Data Structures. The author talks a lot about why structuring your program and managing access patterns is key to performance.

There's a Qt Canvas 3D module in Qt 5.5 that provides WebGL-like interface to hardware accelerated 3D. It is layered on top of existing Qt's OpenGL support.
As for non-QML stuff, on WinRT Qt uses ANGLE, so if you stick to functions provided by Qt (e.g. QOpenGLFunctions) and not try to talk to the driver directly it should work just fine cross-platform.