Random graphical artefacts on QT 5.14 with OpenGL on Intel HD graphics

Matthias St.

Hello,

I am currently trying to fix a Qt/QML OpenGL problem that can be observed with Intel HD Graphics on Windows 10. Sporadically, a black triangle is drawn across the whole window (usually completely diagonal with varying 3rd vertex position). It disappears shortly after, especially after the uses moves the mouse. This is very annoying during user interaction.

I attached a screenshot. Has anyone had a similar problem or knows how to fix it?

The problem appeared after upgrading from an old Intel driver (26.20.100) to a recent one (27.20.100). We are currently using Qt 5.14.0 and the latest Visual Studio 2019. When trying out an old build (Visual Studio 2013) with Qt 5.9.2, the problem cannot be reproduced. When using the angle backend, no problems can be observed (but performance is very slow). On computers with dedicated graphics cards, there is also no problem.

System specs:

QT: 5.14.0
Dynamic GL LibGL Vendor: Intel
Renderer: Intel(R) HD Graphics 530 (also reproducible on the 6xx series)
Version: 4.6.0 - Build 27.20.100.9316

Thanks for any suggestions for how to address this,
Matthias

Pl45m4

@Matthias-St said in Random graphical artefacts on QT 5.14 with OpenGL on Intel HD graphics:

Qt 5.14.0

Have you tested it with 5.15?
It's the latest Qt5 stable version and a lot of stuff / bugs got fixed there (if this is a Qt issue).

nagesh

@Matthias-St Does this "Random graphical artefacts" appear when you run your application?

Matthias St.

@Pl45m4 Hi, thank you for your reply. I updated to the latest 5.15 version but nothing improved. I could not find any QT release notes that appear to address this issue either.

Matthias St.

@nagesh Yes, they appear when I run the application. The frequency of artefacts increases when the application renders more data (we basically draw frequently updating plots)

nagesh

@Matthias-St I guess there might be problem with application drawing(some co-ordinate calculation). Try to draw the plots in fixed position and check whether these artefacts do appear?

hypnos97

@ Matthias-St
I also had a similar situation

Matthias St.

I maybe found a solution by enabling the new Rendering Interface in Qt 5.15. So far, there were no issues after executing the following line of code very early in the main function:

QQuickWindow::setSceneGraphBackend(QSGRendererInterface::OpenGLRhi);

This does not yet mean that the problems are gone, but it's a way I will now test out on other machines to see if this really works (and does not break anything else).

ufukgun

When i change "setSceneGraphBackend", i have received many shader errors and display artifacts.
My problem still continues.

Qt 5.15.2
Visual Studio 2019

JKSH

@Matthias-St said in Random graphical artefacts on QT 5.14 with OpenGL on Intel HD graphics:

Intel HD Graphics on Windows 10

Yeah, Intel's OpenGL support is buggy. (Example: https://bugreports.qt.io/browse/QTBUG-69538 )

@ufukgun said in Random graphical artefacts on QT 5.14 with OpenGL on Intel HD graphics:

When i change "setSceneGraphBackend", i have received many shader errors and display artifacts.
My problem still continues.

Qt 5.15.2
Visual Studio 2019

Try a Direct3D backend instead of the OpenGL backend.

Alternatively, try using ANGLE instead of the Intel's OpenGL drivers by setting the environment variable, QT_OPENGL=angle

Note: You must set the backend before initializing your first window.

Toeger

Same problem on Intel UHD Graphics on Qt 5.15.1 (but not on Intel HD Graphics 620), QQuickWindow::setSceneGraphBackend(QSGRendererInterface::OpenGLRhi); fixed it.
However, the fix caused curves in my graph to not render.
The reason was that I used the flag useOpenGL: true from QtCharts.AbstractSeries to speed up rendering which seems to be incompatible with OpenGLRhi. Removing useOpenGL: true fixed the missing curves issue.