Hi Christian, On Tue, Jun 2, 2009 at 12:19 AM, Christian Sam <osgfo...@tevs.eu> wrote: > - the first thing that confused me was, that Y/Z-vector directions are now > the openGL-way. (is there a reason why OSG normally uses Y as forward-vector?)
Yes there is a reason. I presume you also want to know what that reason is... well the OpenGL coordinate frame is essentially screen centric, with Y going up the screen, X to the right, and the +Z going out from the screen. The OSG's coordinate frame is world centric, so +Z is height, +Y is north, +X is east. The models we load a world centric so the OSG's default coordinate fame matches the world. Robert. > - i also often encounterd the functions "getCoordinateFrame(Vec3&)" and > "getUpVector(cf)", e.g: > > Code: > > CoordinateFrame eyePointCoordFrame = getCoordinateFrame( eye ) > if (intersect(eye+getUpVector(eyePointCoordFrame)*distance,... > > > > i have not much practice with matrix transformations, so its a little bit > hard for me to understand the sense of this, but i assume the following: eye > is the position of the camera, and the camera has it's own local > coordinate-system. getCoordinateFrame() / getXVector() provide the world > coordinates from such local coordinate frame. > > i looked up the implentation of getCoordinateFrame(), but i couldn't find out > how it is accomplished, can you explain me how this is done? I'm afraid I can't really make sense of the problem you are having to so can't answer this one. Robert. _______________________________________________ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
