c++ - OSGViewer in Qt's TabWidget -

i using openscenegraph 3.0.1 , having problem qt integration using the

osgqt::glwidget when adding tab control during startup (inside constructor of main window.

mainwindow::mainwindow(qwidget* parent)     :  qmainwindow(parent), ui(new ui::mainwindow) {     ui->setupui(this);      qwidget* viewerwidget = new myviewerwidget(new osgviewer::viewer());      ui->tabwidget->addtab(viewerwidget, "my osg view");      // tab entry added nothing see empty osg window } 

it works, when calling code menu after displaying main window:

void gcdrp::mainwindow::on_actioncreate_simulation_view_triggered() {     qwidget* viewerwidget = new myviewerwidget(new osgviewer::viewer());      ui->tabwidget->addtab(viewerwidget, "my osg view");      // tab content visible (as expected) } 

it seems scene graph screwed up. ideas?

works setminimumsize:

qwidget* viewerwidget = new myviewerwidget(new osgviewer::viewer());  viewerwidget->setminimumsize( ui->tabwidget->width(), ui->tabwidget->height());