[osg-users] problem zooming using mouse middle scroll in trackballmanipulator

[Srikanth Bemineni]

Hi,

Can somebody please reply to the below question.
Is there a CJM or Postscript output support in Openscenegraph

Srikanth

Srikanth Bemineni wrote:
> I am experimenting with the osgQTviewer.I am not able to zoom in when 
> the mouse wheel is scrolled.I am using trackballmanipulator.I am not 
> able to find a good documentation about camera manipulators.Even the 
> Reference doc doesn't mention the explanation of manipulators.
>
> AdapterWidget::AdapterWidget( ViewerQT *source ,QWidget * parent, 
> const char * name, const QGLWidget * shareWidget, WindowFlags f):
> #if USE_QT4
> QGLWidget(parent, shareWidget, f)
> #else
> QGLWidget(parent, name, shareWidget, f)
> #endif
> {
> m_source = source;
> resize( 800 ,600 );
> /* To Remove this */
> /*
> * // create the window to draw to.
> * */
> osg::ref_ptr<osg::GraphicsContext::Traits> traits = new 
> osg::GraphicsContext::Traits;
> traits->x = 200;
> traits->y = 200;
> traits->width = 800;
> traits->height = 600;
> traits->windowDecoration = true;
> traits->doubleBuffer = true;
> traits->sharedContext = 0;
>
> osg::ref_ptr<osg::GraphicsContext> gc = 
> osg::GraphicsContext::createGraphicsContext(traits.get());
>
>
> _gw = new osgViewer::GraphicsWindowEmbedded(traits.get());
> #if USE_QT4
> setFocusPolicy(Qt::ClickFocus);
> #else
> setFocusPolicy(QWidget::ClickFocus);
> #endif
> }
> ..
> ... all the other event handling
> ...
>
>
>
> void AdapterWidget::mouseMoveEvent( QMouseEvent* event )
> {
> _gw->getEventQueue()->mouseMotion(event->x(), event->y());
> }
>
> void AdapterWidget::wheelEvent( QWheelEvent *event )
> {
> //m_source->wheelEvent( event );
> if( event->delta() > 0 )
> _gw->getEventQueue()->mouseScroll(osgGA::GUIEventAdapter::SCROLL_UP );
> else
> _gw->getEventQueue()->mouseScroll(osgGA::GUIEventAdapter::SCROLL_DOWN );
> }
>
> ViewerQT::
> ViewerQT(QWidget * parent, const char * name, const QGLWidget * 
> shareWidget , WindowFlags f ):
> AdapterWidget( this , parent, name, shareWidget, f )
> {
>
> znear = 1.0f;
> zfar = 10000.0f;
> getCamera()->setViewport(new osg::Viewport(0,0,width(),height()));
> //getCamera()->setProjectionMatrixAsPerspective(30.0f, 
> static_cast<double>(width())/static_cast<double>(height()), 1.0f, 
> 10000.0f);
>
>
> getCamera()->setGraphicsContext(getGraphicsWindow());
> /* To Remove*/
> osg::ref_ptr<osgGA::StateSetManipulator> statesetManipulator = new 
> osgGA::StateSetManipulator(getCamera()->getStateSet());
> addEventHandler(statesetManipulator.get());
> /*to remove end*/
>
> addEventHandler(new PickHandler());
>
> setThreadingModel(osgViewer::Viewer::SingleThreaded);
>
> connect(&_timer, SIGNAL(timeout()), this, SLOT(updateGL()));
> _timer.start(10);
> _manipulator = new osgGA::TrackballManipulator;
> setCameraManipulator(_manipulator);
> cout<<"Minimum distance "<<_manipulator->getMinimumDistance()<<endl;
> cout<<"Homepostion 
> compute"<<_manipulator->getAutoComputeHomePosition()<<endl;
> //_manipulator->setAutoComputeHomePosition(false);
> _manipulator->setMinimumDistance(1000);
> osg::Vec3d eye;
> osg::Vec3d center;
> osg::Vec3d up;
> _manipulator->getHomePosition( eye , center , up );
> cout<<"x y z "<< eye.x()<<eye.y()<<eye.z()<<endl;
> cout<<"x y z "<< center.x()<<center.y()<<center.z()<<endl;
> cout<<"x y z "<< up.x()<<up.y()<<up.z()<<endl;
> }
> void
> ViewerQT::
> VwheelEvent( QWheelEvent *event )
> {
>
> cout<<event->delta()<<endl;
> if( event->delta() > 0 )
> {
> znear = znear + 120.0f;
> }
> else
> {
> if( (znear - 120) >= 1.0 )
> {
> znear = znear - 120;
> }
> }
>
> }
>
> void
> ViewerQT::
> paintGL()
> {
> osg::Vec3d eye;
> osg::Vec3d center;
> osg::Vec3d up;
> _manipulator->getHomePosition( eye , center , up );
> cout<<"eye x y z "<< eye.x()<<" "<<eye.y()<<" "<<eye.z()<<endl;
> cout<<"center x y z "<<center.x()<<" "<<center.y()<<" 
> "<<center.z()<<endl;
> cout<<"up x y z "<< up.x()<<" "<<up.y()<<" "<<up.z()<<endl;
> frame();
> }
>
>
> and this is how I am creating the Viewer window.
> I tried to move the perspective view.
> I tried to translate the camera matrix.
> I tried to set the home positon
> but none of the above things seems to work in moving the camera or 
> zooming.I am new to opengl and open scene graph any guide would be 
> really helpful.
>
> Thank You
>


-- 
With Regards
Srikanth Bemineni
Geotrace Technologies
281-497-8440 extn 228