Qwt 6.3.0 with Qt 6.8.2 - Antialiasing problem with QwtPlotOpenGLCanvas

[Uwe]

Be aware that multisampling increases the GPU load and you might have an impact on the performance by choosing too many samples. So 16 might be too much.
Another question is of course why multisampling is enabled in your application with Qt 6.7 and not with Qt 6.8.

Uwe

[stsorg]

Another question is of course why multisampling is enabled in your application with Qt 6.7 and not with Qt 6.8.

Uwe

In the previous version of my application I work with Qwt 6.2.0 and Qt 6.5.3 (not Qt 6.7.1). Here QSurfaceFormat::samples() returns 4. So multisampling is enabled.
In the new verion of my application I use Qwt 6.3.0 and Qt 6.8.0. Here QSurfaceFormat::samples() returns -1. That means that multisampling is disabled and I have to use QSurfaceFormat::setSamples.

I now tried to use setSamples(8) in the previous version of my application, but I only see a black screen. Is this because of Qt or Qwt? Is there another solution.