My guess is that, at the time you do the query, you haven't rendered a frame yet. If so, the Viewer object hasn't queried the manipulator matrix yet. You have the source code, so you can easily verify this with a debugger. Paul Martz Skew Matrix Software LLC http://www.skew-matrix.com <http://www.skew-matrix.com/> +1 303 859 9466
_____ From: [email protected] [mailto:[email protected]] On Behalf Of ami guru Sent: Thursday, April 02, 2009 8:05 AM To: OpenSceneGraph Users Subject: [osg-users] default coordinate system and camera - newbie Hello Paul, I have made the following changes, still having the same value: *************************************** int main() { //Creating the viewer osgViewer::Viewer viewer ; viewer.setCameraManipulator(new osgGA::TrackballManipulator()); //add some event handler //to show the statistics viewer.addEventHandler(new osgViewer::StatsHandler); /* get camera related information */ osg::Vec3f eye; osg::Vec3f dir; osg::Vec3f up; viewer.getCamera()->getViewMatrixAsLookAt(eye,dir,up); cout << "The eye vector: " << eye.x() << " " << eye.y() << " " << eye.z() << endl; cout << "The look at position: " << dir.x() << " " << dir.y() << " " << dir.z() << endl; cout << "The up vector is: " << up.x() << " " << up.y() << " " << up.z() << endl; *************************************** ---------- Forwarded message ---------- From: ami guru <[email protected]> Date: Thu, Apr 2, 2009 at 2:39 AM Subject: Fwd: [osg-users] default coordinate system and camera - newbie To: OpenSceneGraph Users <[email protected]> Hello Paul, I have the following snippet that deals with the viewer ******************************' int main() { //Creating the viewer osgViewer::Viewer viewer ; //add some event handler //to show the statistics viewer.addEventHandler(new osgViewer::StatsHandler); /* get camera related information */ osg::Vec3f eye; osg::Vec3f dir; osg::Vec3f up; viewer.getCamera()->getViewMatrixAsLookAt(eye,dir,up); cout << "The eye vector: " << eye.x() << " " << eye.y() << " " << eye.z() << endl; cout << "The look at position: " << dir.x() << " " << dir.y() << " " << dir.z() << endl; cout << "The up vector is: " << up.x() << " " << up.y() << " " << up.z() << endl; //Creating the root node osg::ref_ptr<osg::Node> root = createSceneGraph(); ............................................................ ............................................................ ****************************'** Could you provide some hint where the bug might be , at least the way to find it? I want to implement a very simple scenario. A camera that moves along with the key press event. I already have that implemented in OpenGL program where i can roll, pitch yaw and slide with user key press event. I want to map that in the scene graph system. I have the following information predefined n = eye - look; u = up * n; v = n * u; To move the camera in an ineractive way i have to have the access to there values . there is a function in the Camera Class called getViewMatrix() , i hope that it is one to access these values. Any more reference would be of great help. ---------- Forwarded message ---------- From: Paul Martz <[email protected]> Date: 2009/4/2 Subject: Re: [osg-users] default coordinate system and camera - newbie To: OpenSceneGraph Users <[email protected]> The CameraManipulator (like TrackballManipulator, for example) determines the default orientation. You can change this default by setting the up vector in the TrackballManipulator. By default, the TrackballManipulator uses positive Z up, so if your code is getting positive Y up, either you have a bug or you are not using the TrackballManipulator or you have changed its default. The default view position is also determined by the CameraManipulator. The TrackballManipulator, for example, has a home position that you can set. By default, it considers the scene bounding volume and tries to position the view so that the entire scene fits within a 50 degree FOV (I think it's 50, not sure). Paul Martz Skew Matrix Software LLC http://www.skew-matrix.com <http://www.skew-matrix.com/> +1 303 859 9466 _____ From: [email protected] [mailto:[email protected]] On Behalf Of ami guru Sent: Wednesday, April 01, 2009 1:58 PM To: OpenSceneGraph Users Subject: [osg-users] default coordinate system and camera - newbie Hello forum, osgViewer , by default uses the world coordinate system that is oriented with positive X to right , positive Z up, and positive Y into the screen. Does that mean the camera' s defualt position is at the origin looking down into the screen which is positive Y? I have tried to extract the vectors using the function ************************' osg::Vec3f eye; osg::Vec3f dir; osg::Vec3f up; viewer.getCamera()->getViewMatrixAsLookAt(eye,dir,up); cout << "The eye vector: " << eye.x() << " " << eye.y() << " " << eye.z() << endl; cout << "The look at position: " << dir.x() << " " << dir.y() << " " << dir.z() << endl; cout << "The up vector is: " << up.x() << " " << up.y() << " " << up.z() << endl; ************************ The eye vector: 0 0 0 The look at position: 0 0 -1 The up vector is: 0 1 0 I was wondering if the up vector be Z axis instead Regards Sajjad _______________________________________________ osg-users mailing list [email protected] http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
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