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Strange Behaviour with a Multi-Monitor-Set and OpenGL

  • Hi,
    I'm working on a tool to present measured BRDF-Values. My workplace is a Laptop with 2 External-Monitors.
    On my Mainwindow i have a Widget-Container which i promote to a C++ Class:

    • class BasicLambertOGLwidget : public QOpenGLWidget, protected QOpenGLFunctions

    So the Tool is working fine, but now comes the problem. By disconnecting the 2 External-Monitors and working only on my Laptop-Monitor the OpenGL widget shows only black, by starting out of the Qt Programm. And if I start the .exe, even the normal GUI like a Button is lost, only a white window is left...
    I can start the Programm with Multi-Monitors, disconnect the Monitors and everything is fine on the Laptop-Monitor.
    But even when i start Qt only on my Laptop and start a new Project with a OpenGL Widget it doesn't work, but when i connect the externals it's ok... Kind of crazy behaviour.

    I updated to Win10, reinstalled VS and QT, but nothing helps.

    Maybe somebody got a solution for this? i would really appreciate help. Its part of my master thesis and i'm going a bit crazy about this...


  • Lifetime Qt Champion

    Hi and welcome to devnet,

    Which version of Qt are you currently using ?

  • Hi there and thx for the welcome,

    it's my first project with Qt and i'am using:
    Qt Creator 4.0.2
    Based on Qt 5.7.0 (MSVC 2013, 32 bit)
    Built on Jun 13 2016 01:04:04
    From revision 47b4f2c738

    Build&Run settings:
    Desktop Qt 5.7.0 MSVC2015_64bit

  • Lifetime Qt Champion

    Can you check against the current 5.6 version ?

  • I was able to check the .exe file on a Laptop of a friend of mine and it worked.
    Same File on my Laptop does not.
    So it seems to be a problem with my hardware, maybe the internal Graphic driver isn't working, because the Nvidia graphic cards starts with external monitors.

    But thx for your input and support.

  • Lifetime Qt Champion

    IIRC nVidia drivers on Windows have had some troubles lately so it could be related.

  • but it works with the nvidia graphic card. If i start the .exe or Qt with forced use of the nvidia graphic card, it looks ok. Only when i start it with the intel hd graphics 3000 it refuse to work. Is there a know problem with intel hd 3000?

  • Lifetime Qt Champion

    Haaaaaa sorry. HD3000 ? Isn't that a pretty old card ?

  • Relatively ;) i've got a Dell XPS 15 L502x with i7 and nvidia GT 540m... from 2011... is 5 years that much old?
    Well i am about to buy a new little 13" Laptop. The Dell isn't soooo mobile. I hope the programm will work with the new Laptop integrated intel HD....
    For now i can live with the workaround to activate the nvidia when starting Qt...
    should i mark this as solved or delete the topic?

  • This post is deleted!

  • Lifetime Qt Champion

    5 years is already pretty old on the computer market.

    Don't delete it, somebody else might also get hit by this problem.

    Did you check if there was any update for the Intel graphic card ?

  • Moderators

    Intel HD 3000 should support something like OpenGL 3.1. First check if you have at least version 2.1 support present in your system. You can use something like GL View or glewinfo from GLEW package.
    If not then make sure you have the latest drivers for your graphics chip.
    Also check what context version and profile you're requesting in your app and check the version you're given.

  • The HD 3000 supports OpenGL up to 3.1 and I reinstalled the newest drivers: Intel Build

    I checked for the context Version with Intel HD:

    Context valid: true
    Really used OpenGl: 2 . 0
    OpenGl information: VENDOR: Google Inc.
    RENDERDER: ANGLE (Intel(R) HD Graphics 3000 Direct3D11 vs_4_1 ps_4_1)

    and on Nvidia:

    Context valid: true
    Really used OpenGl: 4 . 5
    OpenGl information: VENDOR: NVIDIA Corporation
    RENDERDER: GeForce GT 540M/PCIe/SSE2
    VERSION: 4.5.0 NVIDIA 368.81

    So my Intel HD uses only 2.0, after some reading i added this to my main.cpp:

    QSurfaceFormat format;
    format.setVersion(3, 1);

    and get this verion out:

    ****Context valid: true
    Really used OpenGl: 3 . 0
    OpenGl information: VENDOR: Google Inc.
    RENDERDER: ANGLE (Intel(R) HD Graphics 3000 Direct3D11 vs_4_1 ps_4_1)

    But its still not working :(
    Here is maybe an explanation? The pre-compiled Windows desktop version of Qt5 is built against ANGLE which only provides OpenGL ES 2 support by implementing it on top of DirectX 9.

    So because of Qt my intel HD uses ANGLE renderer and my tool isn't working maybe because of ANGLE? Is this the Problem?
    How can I check what context version and profile my OpenGL-Widget is requesting?

    I tried to force Qt to use the native-OpenGL Modus for the Intel HD by adding this to the main: Qt::AA_UseDesktopOpenGL;

    but it still uses ANGLE...

  • Solved:
    So i added this to the main.cpp:
    instead of:

    and now i get rid of the ANGLE driver:

    Context valid: true
    Really used OpenGl: 3 . 1
    OpenGl information: VENDOR: Intel
    RENDERDER: Intel(R) HD Graphics 3000
    VERSION: 3.1.0 - Build
    GLSL VERSION: 1.40 - Intel Build

    And now it's working, big thx for your help and for the context version suggestion, that was the key...

  • Moderators

    Great that you found the flag. Since version 5.5 Qt on Windows does that dynamic choosing of the OpenGL driver. Since you always want the desktop version you can also build Qt yourself with a configure option -opengl desktop. This would disable ANGLE support entirely so that you wouldn't need the flag and also shrink the library a bit and reduce the number of dependencies for deployment.