Hi,
I'm playing with the osgcompositeviewer example in order to load and show the
axes in the scene. I want that when I rotate the model in the first view, the
axes get updated accordingly, but I don't want them to change position or allow
the user to zoom them.
So, I got this thing running (at least I think so), but I' would like to know
if this is the right way to do this.
In the View three I load the axes.osg file and add it as a child of a
PositionAttitudeTransform node. This transform will be the scene node of the
third view. Also I rotate the axes node so the Y axis will be pointing upwards
and the Z axis will increase towards me.
Code:
// Should check the pointers...
osg::ref_ptr<osg::Node> axes = osgDB::readNodeFile("axes.osg");
axes->setName( "AXES" );
osg::ref_ptr<osg::PositionAttitudeTransform> pat = new
osg::PositionAttitudeTransform;
pat->setName( "PAT" );
pat->setAttitude( osg::Quat( osg::DegreesToRadians( 90.0 ),
osg::X_AXIS ) );
pat->addChild( axes );
pat->addUpdateCallback( new AttitudeCallback(
viewer.getView(0)->getCamera() ) );
view->setSceneData( pat.get() );
Now, for the update of the axes node I used a callback:
Code:
class AttitudeCallback: public osg::NodeCallback {
public:
AttitudeCallback( osg::Camera* c ) : NodeCallback(), cam( c ) {
}
virtual void operator ()( osg::Node* node, osg::NodeVisitor* vis ) {
const osg::Matrixd vmat = cam->getViewMatrix();
std::cout << "CALLBACK: " << node->getName() << std::endl;
osg::ref_ptr<osg::PositionAttitudeTransform> pat =
dynamic_cast<osg::PositionAttitudeTransform*>( node );
if( pat ) {
const osg::Quat axis_rot( osg::DegreesToRadians( 90.0 ),
osg::X_AXIS );
pat->setAttitude( /*axis_rot **/ vmat.getRotate() * axis_rot );
pat->setScale( osg::Vec3d( 0.5, 0.5, 0.5 ) );
}
traverse( node, vis );
}
private:
osg::ref_ptr<osg::Camera> cam;
};
I'm wondering whether instead of using a CompositeViewer, I could use the
single Viewer and set a new viewport/camera to host the axes node.
And, if when I create the PositionAttitudeTransform in the third view and set
then the scale and remove the pat->setScale(...) line from the callback, the
axes don't get scaled at all! Why is that?
...
Thank you and sorry for this huge post!!
Cheers,
Andrés
------------------
Read this topic online here:
http://forum.openscenegraph.org/viewtopic.php?p=60392#60392
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