The upper left 3x3 of the local to world matrix is the orthonormal basis for the current orientation of the car. If the car is modeled so that the front of the car is positive X, then the current direction vector is just the first three elements of the local to world matrix. You can get the local to world matrix from the MatrixTransform. 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 Ümit Uzun Sent: Sunday, March 29, 2009 3:45 PM To: OpenSceneGraph Users Subject: [osg-users] Getting model's direction vector from MatrixTransform? Hi All, I have an simple math question which I had resolved before but now I can't figure out what would be the problem. I have car model which's direction is x coordinate. I want to translate it by using it's current direction. So I need to know it's next visit coordinate while it is rotating to left or right. So this is my math; carMatrixTransform->get(quad); osg::Vec3d carDirection = quad * osg::Vec3d(1.0, 0.0, 0.0); // getting car's x direction vector. Then using carDirection, I calculate each next related coordinates respectively by using iterator. osg::Vec3d DestinationPos, SourcePos; DestinationPos = SourcePos + carDirection * iterator; (iterator >= 0) Do you think it is wrong? Best Regards. -- Ümit Uzun
_______________________________________________ osg-users mailing list [email protected] http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
