I hacked the Quick Start Guide example to draw two large quads instead of two cows and you're absolutely right! One of the quad vertices has to be inside the polytope in order for picking to work. This seems like a bug in the Intersector classes. Either submit a fix, or alert Robert to this when he's back from vacation. -Paul
_____ From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of alessandro terenzi Sent: Wednesday, April 18, 2007 2:30 AM To: osg users Subject: Re: [osg-users] mouse picking problem I cleaned up my code and here a simple example showing my problem: ...here's the handle method: bool myEventHandler::handle( const osgGA::GUIEventAdapter& ea, osgGA::GUIActionAdapter& aa ) { osgViewer::Viewer* viewer = dynamic_cast<osgViewer::Viewer*>( &aa ); if (!viewer) return false; switch( ea.getEventType() ) { case osgGA::GUIEventAdapter::PUSH: case osgGA::GUIEventAdapter::MOVE: { _mX = ea.getX(); _mY = ea.getY(); return false; } case osgGA::GUIEventAdapter::RELEASE: { if (_mX == ea.getX() && _mY == ea.getY ()) { if (pick( ea.getXnormalized(),ea.getYnormalized(), viewer )) return true; } return false; } default: return false; } } ...and here's the pick method: bool myEventHandler::pick( const double x, const double y, osgViewer::Viewer* viewer ) { if (!viewer->getSceneData()) // Nothing to pick. return false; double w( .05 ), h( .05 ); osgUtil::PolytopeIntersector* picker = new osgUtil::PolytopeIntersector(osgUtil::Intersector::PROJECTION, x-w, y-h, x+w, y+h ); osgUtil::IntersectionVisitor iv(picker); viewer->getCamera()->accept(iv); if (picker->containsIntersections()) { std::cout<< "Found intersections..."<<std::endl; osg::NodePath& nodePath = picker->getFirstIntersection().nodePath; unsigned int idx = nodePath.size(); while (idx--) { // look for osg::Geode object osg::Geode* my_geode = dynamic_cast<osg::Geode*>(nodePath[idx]); if(my_geode == NULL) continue; std::cout<< "Picking successful..."<<std::endl; break; } } else { std::cout<<"Picking failed [no intersections]... "<<std::endl; return false; } return true; } ...and finally the main: int main(int argc, char* argv[]) { osgViewer::Viewer viewer; osg::ref_ptr<osg::Node> scene = createPyramid(50.0f, 50.0f); viewer.addEventHandler(new myEventHandler); viewer.setSceneData(scene.get()); return viewer.run(); } The behaviour I'm experiencing is as follow: after clicking far away from the pyramid I got this output on the console: Picking failed [no intersections]... after clicking inside one of the pyramid's faces, I got: Picking failed [no intersections]... finally when I clicked on the apex, I got: Found intersections... Picking successful... Any Idea about what is wrong? Thanks. Alessandro On 4/17/07, Paul Martz <[EMAIL PROTECTED]> wrote: The Quick Start Guide example code is based on the osgkeyboardmouse example, just a simplified version to demonstrate mouse-based picking. You might try creating a simple reproducer program that draws a single large quad and fails to pick it when you click in the quad center. I'd like to see that code. -Paul > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] On Behalf Of > Andreas Goebel > Sent: Tuesday, April 17, 2007 1:14 PM > To: osg users > Subject: Re: [osg-users] mouse picking problem > > alessandro terenzi schrieb: > > I'm implementig mouse picking into my application...I used > the code of > > the Quick Start Guide as a reference but, instead of looking for > > osg::MatrixTransform node, I look for my osg::Group derived > > objects...my problem is that picking seems to work just > when I click > > close to vertices but it doesn't work if I click in the middle of a > > polygon defined by those same vertices. I thought that the various > > intersectors checked for any intersection against a bounding > > volume...any suggestion? > > > > Thanks. > > Alessandro > Hi, > > I haven´t read the Quick-Start-Guide, but in case you modify > the vertices in your geometry you have to call dirtyBound() > after that to force recomputing the boundingBox after the > next traversal. > > This will give you the right picks. > > Regards, > > Andreas > > _______________________________________________ > osg-users mailing list > [email protected] > http://openscenegraph.net/mailman/listinfo/osg-users <http://openscenegraph.net/mailman/listinfo/osg-users> > http://www.openscenegraph.org/ _______________________________________________ osg-users mailing list [email protected] <mailto:[email protected]> http://openscenegraph.net/mailman/listinfo/osg-users http://www.openscenegraph.org/
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