[osg-users] osg::Node can not be displayed front of the Earth on the screen

[Ali Ozdin]

Hi,

I drew an osg Node and I want to put it on the center of the screen like any labelControl. How can I do that? I put a sample code below. 

If I change the line from 

Code:
viewer.setSceneData( mainGroup );

 to 
Code:
viewer.setSceneData( nn.get() );


and remove these two lines 

Code:
manipulator = new EarthManipulator(  arguments ); 
viewer.setCameraManipulator( manipulator ); 



I am only able to see the geometry which I draw. However if I setSceneData as mapNode and geometry which are in "mainGroup" and if my camera manipulator is EarthManipulator; I am only able to see the earth. 
To sum up, I want to see the earth in the back and I want to put my geometry front of the earth and on the center of the screen. 




Code:
osg::ref_ptr<osg::Node> createSceneGraph() 
{ 
osg::ref_ptr<osg::Geometry> geom = new osg::Geometry; 
osg::ref_ptr<osg::Vec3Array> v = new osg::Vec3Array; 
geom->setVertexArray( v.get() ); 

//horizontal 
v->push_back( osg::Vec3( -1.f, 1.f, 0.f ) ); 
v->push_back( osg::Vec3( -0.6f, 1.f, 0.f ) ); 
v->push_back( osg::Vec3( -0.4f, 1.f, 0.f ) ); 
v->push_back( osg::Vec3( 0.f, 1.f, 0.f ) ); 

//vertical 
v->push_back( osg::Vec3( -0.5f, 1.f, 0.5f ) ); 
v->push_back( osg::Vec3( -0.5f, 1.f, 0.1f ) ); 
v->push_back( osg::Vec3( -0.5f, 1.f, -0.5f ) ); 
v->push_back( osg::Vec3( -0.5f, 1.f, -0.1f ) ); 


osg::ref_ptr<osg::Vec4Array> c = new osg::Vec4Array; 
geom->setColorArray( c.get() ); 
geom->setColorBinding( osg::Geometry::BIND_OVERALL ); 
c->push_back( osg::Vec4( 1.f, 1.f, 1.f, 1.f ) ); 

osg::ref_ptr<osg::Vec3Array> n = new osg::Vec3Array; 
geom->setNormalArray( n.get() ); 
geom->setNormalBinding( osg::Geometry::BIND_OVERALL ); 
n->push_back( osg::Vec3( 0.f, -1.f, 0.f ) ); 

osg::LineWidth* linewdth = new osg::LineWidth(); 
linewdth->setWidth(25.0); 
geom->getOrCreateStateSet()->setAttributeAndModes( linewdth, osg::StateAttribute::ON ) ; 
geom->addPrimitiveSet( new osg::DrawArrays( osg::PrimitiveSet::LINES, 0, 8 ) ); 

osg::ref_ptr<osg::Geode> geode = new osg::Geode; 
geode->addDrawable( geom.get() ); 
return geode.get(); 
} 

int main(int argc, char** argv) 
{ 
osg::ArgumentParser arguments(&argc,argv); 
viewer.setUpViewInWindow(100,100,500,500); 
viewer.getDatabasePager()->setUnrefImageDataAfterApplyPolicy( true, false ); 
osgDB::Registry::instance()->getObjectWrapperManager()->findWrapper("osg::Image"); 
manipulator = new EarthManipulator( arguments ); 
viewer.setCameraManipulator( manipulator ); 

osg::Group* mainGroup = new osg::Group(); 
osg::Group* group = MapNodeHelper().load(arguments, &viewer); 
osg::ref_ptr<osg::Node> nn = createSceneGraph(); 

mainGroup->addChild(nn.get()); 
mainGroup->addChild(group); 

viewer.setSceneData( mainGroup ); 
viewer.run(); 
}



Thank you!

Cheers,
Ali

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http://forum.openscenegraph.org/viewtopic.php?p=72998#72998