[osg-users] Question about plane intersections
Gentlemen, Can anyone point me to something that would be useful in OSG for solving the problem of making a set of contour lines similar to those seen on maps? I'd like to provide osg with a plane and get the shape created by the intersection with the plane. Your advice is greatly appreciated. Thanks, John Argentieri ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
Re: [osg-users] Question about plane intersections
Hi John, Can anyone point me to something that would be useful in OSG for solving the problem of making a set of contour lines similar to those seen on maps? I'd like to provide osg with a plane and get the shape created by the intersection with the plane. I'm sure others can provide more mathematically-inclined answers (perhaps even something already in OSG), but I could see doing that by making a shader that draws lines when the world-space Z coordinate is a given value (or a given multiple of a given value, or whatever). Not sure how familiar you are with shader programming, but it should be pretty easy. Of course, if you need the result for other calculations rather than just for display (or if you need it to be arbitrary planes, or other things) this won't work. Hope this helps, J-S -- __ Jean-Sebastien Guay[EMAIL PROTECTED] http://www.cm-labs.com/ http://whitestar02.webhop.org/ ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
Re: [osg-users] Question about plane intersections
On Wed, Sep 24, 2008 at 1:02 PM, Argentieri, John-P63223 [EMAIL PROTECTED] wrote: Gentlemen, Can anyone point me to something that would be useful in OSG for solving the problem of making a set of contour lines similar to those seen on maps? I'd like to provide osg with a plane and get the shape created by the intersection with the plane. Your advice is greatly appreciated. Thanks, John Argentieri Have you looked into osgUtil::PlaneIntersector? It will return the results of an intersection at a set of polylines. You can then create osg::Geometry from the polylines to visualize it. Glenn -- Glenn Waldron : Pelican Mapping : http://pelicanmapping.com : +1.703.652.4791 ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
Re: [osg-users] Question about plane intersections
Both very nice ideas. Thanks guys! From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Glenn Waldron Sent: Wednesday, September 24, 2008 1:25 PM To: OpenSceneGraph Users Subject: Re: [osg-users] Question about plane intersections On Wed, Sep 24, 2008 at 1:02 PM, Argentieri, John-P63223 [EMAIL PROTECTED] wrote: Gentlemen, Can anyone point me to something that would be useful in OSG for solving the problem of making a set of contour lines similar to those seen on maps? I'd like to provide osg with a plane and get the shape created by the intersection with the plane. Your advice is greatly appreciated. Thanks, John Argentieri Have you looked into osgUtil::PlaneIntersector? It will return the results of an intersection at a set of polylines. You can then create osg::Geometry from the polylines to visualize it. Glenn -- Glenn Waldron : Pelican Mapping : http://pelicanmapping.com : +1.703.652.4791 ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
Re: [osg-users] Question about plane intersections
John, If you just want it visually in a map style format, you can texture the hill with a banded texture, generate the texcoordinates based on a texgen node, and then view it in ortho from the top. David ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
