Hi Peter, I was struggling with the same thing last week, but I gave up after a few days. I ended up writing a class derived from QObject that contains a osg::Camera node with orthographic projection to do the drawing with OSG. Fortunately I have only a handful of widgets to convert.
BTW, is there a way to dump the OpenGL state after calling QPainter's drawing methods? The .begin() and .end() by themselves don't seem to cause any problems but maybe some state change is happening? Regards, Can. On 6/12/07, Peter O <[EMAIL PROTECTED]> wrote:
No problem Robert. Thanks for having a look. Anyone else got any ideas? Cheers, Pete. On 6/12/07, Robert Osfield < [EMAIL PROTECTED]> wrote: > I'm afraid you're off the map w.r.t my experience with QT. > > On 6/12/07, Peter O <[EMAIL PROTECTED]> wrote: > > Hi Robert, > > > > Normally you would use paintGL. However, the QT overpainting example says > > that to get overpainting to work you need to implement the paintEvent method > > instead (which normally calls paintGL). The osg rendering code is in that > > method sandwitched between the QPainter stuff. > > > > From the example doc: > > > > "In this example, we implement paintEvent() rather than paintGL() to render > > our scene. When drawing on a QGLWidget, the paint engine used by QPainter > > performs certain operations that change the states of the OpenGL > > implementation's matrix and property stacks. Therefore, it is necessary to > > construct a QPainter for use on the widget before making any OpenGL calls." > > > > http://doc.trolltech.com/4.3/opengl-overpainting.html > > > > Thanks again for helping. > > > > Cheers, > > > > > > Pete. > > > > On 6/12/07, Robert Osfield <[EMAIL PROTECTED] > wrote: > > > Why do you comment out the paintGL? This is what should be redrawing. > > > > > > > On 6/12/07, Peter O <[EMAIL PROTECTED]> wrote: > > > > Hi Robert, > > > > > > > > Sorry, I didn't want to just fire a lot of code at you but I guess it > > would > > > > actually be quite helpful to see the whole thing ;) I've attached the > > main > > > > viewer code at the end of this email. > > > > > > > > At the moment, when mouse moves cause the camera to change the update() > > > > method is called, triggering a paintEvent. Additionally, if the window > > is > > > > resized a paintEvent will be triggered by QT. > > > > > > > > Cheers, > > > > > > > > Pete. > > > > > > > > P.S. I think you met one of my work collegues (Paul Fotheringham) at the > > > > last Highland Gathering :) > > > > > > > > main.cpp > > > > > > > > int main( int argc, char **argv ) > > > > { > > > > QApplication a( argc, argv ); > > > > > > > > Viewer viewer( 0 ); > > > > viewer.setMaximumSize ( 500, 500 ); > > > > viewer.show(); > > > > > > > > for ( int i = 1; i < argc; ++i ) > > > > { > > > > viewer.loadMesh( argv[ i ] ); > > > > } > > > > > > > > return a.exec(); > > > > } > > > > > > > > Viewer.h > > > > > > > > class Viewer : public QGLWidget > > > > { > > > > Q_OBJECT > > > > > > > > public: > > > > Viewer( QWidget* parent ); > > > > > > > > void loadMesh( const QString& ); > > > > > > > > osgUtil::SceneView* sceneView() { return m_scene.get(); > > } > > > > const osgUtil::SceneView* sceneView() const { return m_scene.get(); > > } > > > > > > > > protected: > > > > virtual void initializeGL(); > > > > virtual void resizeGL( int, int ); > > > > //virtual void paintGL(); > > > > > > > > virtual void paintEvent ( QPaintEvent * ); > > > > virtual void keyPressEvent ( QKeyEvent * ); > > > > virtual void mousePressEvent ( QMouseEvent * ); > > > > virtual void mouseReleaseEvent ( QMouseEvent * ); > > > > virtual void mouseDoubleClickEvent ( QMouseEvent * ); > > > > virtual void mouseMoveEvent ( QMouseEvent * ); > > > > > > > > private: > > > > void updateCamera(); > > > > void zoom ( int dy ); > > > > void rotate( int dx, int dy ); > > > > void pan ( int dx, int dy ); > > > > > > > > // Data > > > > > > > > // Mouse > > > > QPoint m_prevMouse; > > > > > > > > // Camera > > > > osg::Quat m_cameraR; > > > > osg::Vec3 m_orbitCentre; > > > > float m_dolly; > > > > > > > > // OSG scene > > > > osg::ref_ptr< osgUtil::SceneView > m_scene; > > > > }; > > > > > > > > Viewer.cpp > > > > > > > > QGLFormat getPixelFormat() > > > > { > > > > QGLFormat fmt; > > > > fmt.setStencil(true); > > > > return fmt; > > > > } > > > > > > > > Viewer::Viewer( QWidget* parent ) > > > > : QGLWidget( getPixelFormat(), parent ) > > > > , m_dolly( 0.2 ) > > > > { > > > > setFocusPolicy( Qt::StrongFocus ); > > > > setAttribute( Qt::WA_NoSystemBackground ); > > > > } > > > > > > > > void Viewer::loadMesh( const QString& fileName ) > > > > { > > > > qDebug() << "Attempting to load: " << fileName; > > > > > > > > osg::Node*const mesh = osgDB::readNodeFile( fileName.toStdString() > > ); > > > > if ( !mesh ) > > > > { > > > > qWarning( "Mesh not loaded!" ); > > > > } > > > > > > > > m_scene->getSceneData()->asGroup()->addChild( mesh > > ); > > > > } > > > > > > > > void Viewer::initializeGL() > > > > { > > > > m_scene = new osgUtil::SceneView; > > > > > > > > m_scene->setDefaults(); > > > > m_scene->setClearColor( osg::Vec4( 247.0 / 255.0, 150.0 / 255.0, > > 150.0 / > > > > 255.0, 1.0) ); > > > > m_scene->getState()->setContextID( > > > > osg::GraphicsContext::createNewContextID() ); > > > > > > > > m_scene->setNearFarRatio( 0.02f ); > > > > > > > > m_scene->setSceneData( new osg::Group ); > > > > > > > > updateCamera(); > > > > } > > > > > > > > void Viewer::resizeGL( int w, int h) > > > > { > > > > qDebug() << "ResizeGL: " << w << " " << h; > > > > > > > > m_scene->setViewport( 0, 0, w, h ); > > > > > > > > const float VFOV = 30.f; > > > > const float ASPECT_RATIO = static_cast< float >( w ) / > > > > static_cast< float >( h > > ); > > > > const float Z_N = 0.002f; > > > > const float Z_F = 1.000f; > > > > > > > > osg::Matrix projection; > > > > projection.makePerspective( VFOV, ASPECT_RATIO, Z_N, Z_F ); > > > > > > > > m_scene->setProjectionMatrix( projection ); > > > > } > > > > > > > > > > > > void Viewer::paintEvent( QPaintEvent * ) > > > > { > > > > qDebug() << "PaintEvent"; > > > > > > > > QPainter painter; > > > > painter.begin(this); > > > > painter.setRenderHint(QPainter::Antialiasing); > > > > painter.setBrush( Qt::red ); > > > > > > > > // Preserve the current GL state. > > > > glPushAttrib( GL_ALL_ATTRIB_BITS ); > > > > glMatrixMode(GL_PROJECTION); > > > > glPushMatrix(); > > > > glMatrixMode(GL_TEXTURE); > > > > glPushMatrix(); > > > > glMatrixMode(GL_MODELVIEW); > > > > glPushMatrix(); > > > > > > > > // Do our OSG stuff... > > > > resizeGL( width(), height() ); > > > > updateCamera(); > > > > > > > > m_scene->update(); > > > > m_scene->cull(); > > > > m_scene->draw(); > > > > > > > > // Restore the old GL state. > > > > glMatrixMode(GL_TEXTURE); > > > > glPopMatrix(); > > > > glMatrixMode(GL_PROJECTION); > > > > glPopMatrix(); > > > > glMatrixMode(GL_MODELVIEW); > > > > glPopMatrix(); > > > > glPopAttrib(); > > > > > > > > // Comment out the following line to make everything work. > > > > painter.drawLine( 0, 0, width(), height() ); > > > > > > > > painter.end(); > > > > > > > > } > > > > > > > > void Viewer::keyPressEvent ( QKeyEvent * k ) > > > > { > > > > switch ( k->key() ) > > > > { > > > > case Qt::Key_Q: > > > > QApplication::exit(); > > > > break; > > > > } > > > > } > > > > > > > > void Viewer::mousePressEvent( QMouseEvent * e ) > > > > { > > > > qDebug() << "mousePressEvent:"; > > > > > > > > m_prevMouse = e->pos(); > > > > > > > > e->accept(); > > > > } > > > > > > > > void Viewer::mouseReleaseEvent( QMouseEvent * e ) > > > > { > > > > e->accept(); > > > > } > > > > > > > > void Viewer::mouseDoubleClickEvent( QMouseEvent * e ) > > > > { > > > > e->ignore(); > > > > } > > > > > > > > void Viewer::mouseMoveEvent( QMouseEvent * e ) > > > > { > > > > const int dx = e->x() - m_prevMouse.x(); > > > > const int dy = e->y() - m_prevMouse.y(); > > > > > > > > m_prevMouse = e->pos(); > > > > > > > > const bool panFlag = ( e->buttons() & Qt::MidButton ); > > > > const bool rotateFlag = ( e->buttons() & Qt::LeftButton ); > > > > const bool zoomFlag = ( e->buttons() & Qt::RightButton ); > > > > > > > > > > > > if ( zoomFlag ) > > > > { > > > > zoom( dy ); > > > > } > > > > else if ( rotateFlag ) > > > > { > > > > rotate( dx, dy ); > > > > } > > > > else if ( panFlag ) > > > > { > > > > pan( dx, dy ); > > > > } > > > > > > > > updateCamera(); > > > > update(); > > > > > > > > e->accept(); > > > > } > > > > > > > > void Viewer::updateCamera() > > > > { > > > > qDebug() << "Update Camera"; > > > > > > > > osg::Matrix vm = osg::Matrix::translate( -m_orbitCentre ); > > > > vm *= osg::Matrix::rotate( m_cameraR.conj() ); > > > > vm.setTrans( vm.getTrans () + osg::Vec3( 0., 0., -m_dolly ) ); > > > > > > > > m_scene->setViewMatrix( vm ); > > > > } > > > > > > > > void Viewer::rotate( int dx, int dy ) > > > > { > > > > const double ROTATE_FACTOR = 0.002 * osg::PI; > > > > > > > > const float cameraYawChange = -dx * ROTATE_FACTOR; > > > > const float cameraPitchChange = -dy * ROTATE_FACTOR; > > > > > > > > m_cameraR = osg::Quat( cameraPitchChange, osg::Vec3( 1., 0., 0. ) ) > > * > > > > m_cameraR; > > > > m_cameraR *= osg::Quat( cameraYawChange , osg::Vec3( 0., 1., 0. ) > > ); > > > > } > > > > > > > > void Viewer::zoom( int dy ) > > > > { > > > > const float MIN_DOLLY = 5.e-2f; > > > > const float MAX_DOLLY = 2.e+0f; > > > > const float ZOOM_SCALE = 0.002; > > > > > > > > if ( m_dolly <= MIN_DOLLY && dy < 0 ) > > > > { > > > > const double PAN_FORWARD_FACTOR = ZOOM_SCALE * MIN_DOLLY; > > > > > > > > const osg::Vec3 cameraZInWorld = m_cameraR * osg::Vec3( 0., 0., > > 1. > > > > ); > > > > > > > > m_orbitCentre += cameraZInWorld * ( dy * PAN_FORWARD_FACTOR ); > > > > > > > > m_dolly = MIN_DOLLY; > > > > } > > > > else if ( m_dolly >= MAX_DOLLY && dy > 0 ) > > > > { > > > > m_dolly = MAX_DOLLY; > > > > } > > > > else > > > > { > > > > const float deltaDolly = dy * ZOOM_SCALE * m_dolly; > > > > > > > > m_dolly += deltaDolly; > > > > > > > > if ( m_dolly > MAX_DOLLY ) > > > > m_dolly = MAX_DOLLY; > > > > else if ( m_dolly < MIN_DOLLY ) > > > > m_dolly = MIN_DOLLY; > > > > } > > > > } > > > > > > > > void Viewer::pan( int dx, int dy ) > > > > { > > > > const float PAN_FACTOR = 0.002; > > > > > > > > const osg::Vec3 cameraXInWorld = m_cameraR * osg::Vec3( 1., 0., 0. > > ); > > > > const osg::Vec3 cameraYInWorld = m_cameraR * osg::Vec3( 0., 1., 0. > > ); > > > > > > > > double deltaPanX = double( dx ) * PAN_FACTOR * m_dolly; > > > > m_orbitCentre -= cameraXInWorld * deltaPanX; > > > > > > > > double deltaPanY = double( -dy ) * PAN_FACTOR * m_dolly; > > > > m_orbitCentre -= cameraYInWorld * deltaPanY; > > > > > > > > } > > > > > > > > On 6/12/07, Robert Osfield < [EMAIL PROTECTED] > wrote: > > > > > Hi Peter, > > > > > > > > > > How do you call the OSG to rendering i.e. your paintGL() method ? I > > > > > can only see set up code in you snippets. > > > > > > > > > > On 6/12/07, Peter O <[EMAIL PROTECTED] > wrote: > > > > > > Hi Robert, > > > > > > > > > > > > Thanks for the reply. > > > > > > > > > > > > Basically, we have a big QT based application with 2D visuals which > > > > appear > > > > > > in normal QT widgets and 3D visuals which we draw using OSG inside > > > > > > QGLWidgets. However, ultimately we would like to be able to draw the > > 2D > > > > > > visuals directly over the 3D scene. > > > > > > > > > > > > We are using QT 4.3.0 and OSG 1.2. > > > > > > > > > > > > My update camera method just sets the view matrix based on some > > current > > > > > > dolly and rotation parameters. > > > > > > > > > > > > void Viewer::updateCamera() > > > > > > { > > > > > > qDebug() << "Update Camera"; > > > > > > > > > > > > osg::Matrix vm = osg::Matrix::translate( -orbitCentre ); > > > > > > vm *= osg::Matrix::rotate( cameraR.conj() ); > > > > > > vm.setTrans( vm.getTrans() + osg::Vec3( 0., 0., -dolly ) ); > > > > > > > > > > > > m_scene->setViewMatrix( vm ); > > > > > > } > > > > > > > > > > > > The resizeGL method updates the viewport and projection matrix. > > > > > > > > > > > > void Viewer::resizeGL( int w, int h) > > > > > > { > > > > > > qDebug() << "ResizeGL: " << w << " " << h; > > > > > > > > > > > > m_scene->setViewport( 0, 0, w, h ); > > > > > > > > > > > > const float VFOV = 30.f; > > > > > > const float ASPECT_RATIO = static_cast< float >( w ) / > > > > > > static_cast< float > > >( h > > > > ); > > > > > > const float Z_N = 0.002f; > > > > > > const float Z_F = 1.000f; > > > > > > > > > > > > osg::Matrix projection; > > > > > > projection.makePerspective( VFOV, ASPECT_RATIO, Z_N, Z_F ); > > > > > > > > > > > > m_scene->setProjectionMatrix( projection ); > > > > > > } > > > > > > > > > > > > The m_scene variable in the paint event method is a > > osgUtil::SceneView > > > > which > > > > > > is set up in the initializeGL method. > > > > > > > > > > > > void Viewer::initializeGL() > > > > > > { > > > > > > m_scene = new osgUtil::SceneView; > > > > > > > > > > > > m_scene->setDefaults(); > > > > > > m_scene->setClearColor( osg::Vec4( 247.0 / 255.0, 150.0 / 255.0, > > > > 150.0 / > > > > > > 255.0, 1.0) ); > > > > > > m_scene->getState()->setContextID( > > > > > > osg::GraphicsContext::createNewContextID() ); > > > > > > > > > > > > m_scene->setNearFarRatio( 0.02f ); > > > > > > > > > > > > m_scene->setSceneData( new osg::Group ); > > > > > > > > > > > > updateCamera(); > > > > > > } > > > > > > > > > > > > If the drawLine command is commented out of the paintEvent > > everything > > > > works > > > > > > otherwise as I said the 3D mesh only appears to be drawn on the > > first > > > > paint > > > > > > event after it is loaded then on the next paint event it disappears. > > > > > > > > > > > > The mesh is added to the scene view using: > > > > > > > > > > > > m_scene->getSceneData()->asGroup()->addChild( mesh > > ); > > > > > > > > > > > > Thanks for any help / suggestions, > > > > > > > > > > > > Pete. > > > > > > > > > > > > > > > > > > > > > > > > On 6/12/07, Robert Osfield < [EMAIL PROTECTED]> wrote: > > > > > > > Hi Peter, > > > > > > > > > > > > > > What be hidden inside the updateCamera() call??? > > > > > > > > > > > > > > Why use overpainting? What effect are you after? > > > > > > > > > > > > > > Robert. > > > > > > > > > > > > > > On 6/11/07, Peter O <[EMAIL PROTECTED] > wrote: > > > > > > > > Hi, > > > > > > > > > > > > > > > > I'm trying to adapt the QT overpainting example ( drawing 2D > > > > primitives > > > > > > and > > > > > > > > text over a 3D scene ) to use osg instead of raw openGL. > > However, > > > > the > > > > > > mesh > > > > > > > > I'm drawing only appears for the first paintEvent and then > > > > disappears > > > > > > from > > > > > > > > the view. If I comment out any qpainter draw commands the mesh > > is > > > > > > correctly > > > > > > > > redrawn and can be rotated etc. > > > > > > > > > > > > > > > > Has anyone managed to get overpainting to work with osg? > > > > > > > > > > > > > > > > Here is my paintEvent method in case anyone can spot any obvious > > > > errors: > > > > > > > > > > > > > > > > void Viewer::paintEvent( QPaintEvent * ) > > > > > > > > { > > > > > > > > qDebug() << "PaintEvent"; > > > > > > > > > > > > > > > > QPainter painter; > > > > > > > > painter.begin(this); > > > > > > > > painter.setRenderHint (QPainter::Antialiasing); > > > > > > > > painter.setBrush( Qt::red ); > > > > > > > > > > > > > > > > // Preserve the current GL state. > > > > > > > > glPushAttrib( GL_ALL_ATTRIB_BITS ); > > > > > > > > glMatrixMode(GL_PROJECTION); > > > > > > > > glPushMatrix(); > > > > > > > > glMatrixMode(GL_TEXTURE); > > > > > > > > glPushMatrix(); > > > > > > > > glMatrixMode(GL_MODELVIEW); > > > > > > > > glPushMatrix(); > > > > > > > > > > > > > > > > // Do our OSG stuff... > > > > > > > > /resizeGL( width(), height() ); > > > > > > > > updateCamera(); > > > > > > > > > > > > > > > > m_scene->update(); > > > > > > > > m_scene->cull(); > > > > > > > > m_scene->draw(); > > > > > > > > > > > > > > > > // Restore the old GL state. > > > > > > > > glMatrixMode(GL_TEXTURE); > > > > > > > > glPopMatrix(); > > > > > > > > glMatrixMode(GL_PROJECTION); > > > > > > > > glPopMatrix(); > > > > > > > > glMatrixMode(GL_MODELVIEW); > > > > > > > > glPopMatrix(); > > > > > > > > glPopAttrib(); > > > > > > > > > > > > > > > > painter.drawLine ( 0, 0, width(), height() ); > > > > > > > > > > > > > > > > painter.end(); > > > > > > > > > > > > > > > > } > > > > > > > > > > > > > > > > Thanks in advance for any tips or help. > > > > > > > > > > > > > > > > Pete. > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > _______________________________________________ > > > > > > > > osg-users mailing list > > > > > > > > [email protected] > > > > > > > > > > > > http://openscenegraph.net/mailman/listinfo/osg-users > > > > > > > > http://www.openscenegraph.org/ > > > > > > > > > > > > > > > _______________________________________________ > > > > > > > osg-users mailing list > > > > > > > [email protected] > > > > > > > > > http://openscenegraph.net/mailman/listinfo/osg-users > > > > > > > http://www.openscenegraph.org/ > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > _______________________________________________ osg-users mailing list [email protected] http://openscenegraph.net/mailman/listinfo/osg-users http://www.openscenegraph.org/
-- Can Ozmen ________________________ Computer Graphics Lab. Sabanci University, Turkey phone: +(90) 216 483 9000 ext 2321 http://graphics.sabanciuniv.edu http://students.sabanciuniv.edu/~canozmen _______________________________________________ osg-users mailing list [email protected] http://openscenegraph.net/mailman/listinfo/osg-users http://www.openscenegraph.org/
