Demo: Integrating OpenSceneGraph with Qt Quick

[podsvirov]

I am also interested osgEarth project.
But I have not checked his work in the context of Qt Quick (Qt 5).
I hope to attend to it in the future (but still do not know when exactly).
I used osgEarth with widgets (osgQt) - try them for first.

[rooi]

Thanks for your reply Konstantin.

With the help of the osgEarth guys I think I've figured it out.
When I change the frame function as such it seems to work. Maybe you could review it and include it in the demo?

Thanks again!

void frame() {
    if (!compositeViewer.valid()) return;

    // Qt bug!?
    QOpenGLContext::currentContext()->functions()->glUseProgram(0);

    /* save current OpenGL state  */
    glPushAttrib(GL_TEXTURE_BIT|GL_LIGHTING_BIT|GL_SCISSOR_BIT|GL_STENCIL_BUFFER_BIT);

    //char* version = (char*)glGetString(GL_VERSION);

    compositeViewer->frame();

    // qpainter uses vertex attribs 3,4,5 so we need to explicitly disable them:
    QOpenGLContext::currentContext()->functions()->glDisableVertexAttribArray(3); 
    QOpenGLContext::currentContext()->functions()->glDisableVertexAttribArray(4); 
    QOpenGLContext::currentContext()->functions()->glDisableVertexAttribArray(5); 
    QOpenGLContext::currentContext()->functions()->glDisableVertexAttribArray(6); 
    QOpenGLContext::currentContext()->functions()->glDisableVertexAttribArray(7); 

    // qpainter requires depth testing to be off 
    glDisable(GL_DEPTH_TEST) ;

    // not sure if this is required; osg changes this when using textures so I reset it to default 
    glPixelStorei(GL_UNPACK_ALIGNMENT,4); 

    glPopAttrib();

}

[cmannett85]

Hi,
In QuickWindowViewer::Hidden::frame(), the call to QOpenGLContext::currentContext() is returning null for me. The osgviewer and Qt's QML examples work perfectly well, and my machine supports FBOs (OpenGL v3.0) - any ideas why a context couldn't be created?

[cmannett85]

I found the problem, the signal/slot connection to the failing method:

@connect(window, SIGNAL(beforeRendering()), this, SLOT(frame()));@

It should be specified as a Qt::DirectConnection as noted in the "QQuickWindow docs":http://qt-project.org/doc/qt-5.0/qtquick/qquickwindow.html#exposure-and-visibility - "Warning: As signals related to rendering might be emitted from the rendering thread, connections should be made using Qt::DirectConnection."

[rooi]

Hi Konstantin,

I recently got some more time to look into your project again. As I stated before I like the way you integrate osg and qt/qml.

I tried to extent the functionality by adding some osg pickers to allow identifying the name and type of a node underneath the mouse. This seems to work initially, but unfortunatly it doesn't after a resize of the window.

Do you have any idea why this occurs? My guess is that something does not get the new window size after a resize, but which object? Hopefully you could give me another pointer to try and get this fixed.

Thank you very much!

Rooi

[rooi]

Hi,

I managed to get the picker to work by doing the following:

Add the following lines to updateViewport()
QSize size(quickItem->boundingRect().size().toSize());
if(view->getCamera()->getGraphicsContext())
view->getCamera()->getGraphicsContext()->resized( 0, 0, size.width(), size.height() );

Thanks.

[alydev]

Is someone can send me the demo ? I can't download it...

[podsvirov]

I am sorry, but the link to the archive is not working.
You can try to get the code via git:
@
git clone git://podsvirov.pro/osg/osgqtquick.git
@

[podsvirov]

Good news: a link to a screenshot and the source code in the archive is working again!

[anu.rastogi]

Hi Konstantin,

Sub: enable multisampling

Your example is really well done, Thanks. Now I want to enable multisampling, but I can not figure out how to enable it. I want to use the buffer mode.
The QOpenGLFramebufferObjectFormat.setSamples(4) does not seem to work. I don't have a very deep knowledge or osg::GraphicsWindow and its traits. But if you can guide me, I can take a look.

Thanks a lot,

[anu.rastogi]

Hi Konstantin,

Sub: enable multisampling

Your example is really well done, Thanks. Now I want to enable multisampling, but I can not figure out how to enable it. I want to use the buffer mode.
The QOpenGLFramebufferObjectFormat.setSamples(4) does not seem to work. I don't have a very deep knowledge or osg::GraphicsWindow and its traits. But if you can guide me, I can take a look.

Thanks a lot,

[Voya]

@rooi
oh I am facing the same problem as you did. when I resize the windows ,it seems that the Qopenglcontext turn to null . so the fbo is initialized failed. using the method you give it does not work . i try to delete the updatafbo it works but the size of texture does not changed any more.

[podsvirov]

Meet osgQtQuick 2.0!

[podsvirov]

Wow! More than 10 000 views :-)
It seems that many who like it!

I repeat: Meet osgQtQuick 2.0!