Ok solved It appears that a GLOBAL surface setInterval overrides the setIntervals I did on my glWidget. Kinda weird that the global one overrides local one if local one was specified, is this a bug ? format.setSwapInterval(0); QSurfaceFormat::setDefaultFormat(format); overrides on widget > QSurfaceFormat format; format.setSwapInterval(0); setFormat(format);

Hi and welcome to devnet, Since your widgett is called PixmapView then in your CanvaTest class you can use ui->PixmapView ..

Thanks for the advice mrjj. I used the translate functions and the save and restore to ensure that each section has a logical coordinate system that makes sense to it.