Re #1: Your whole-earth database is in geocentric (earth-centered XYZ) coordinates. In the class osg::EllipsoidModel (in osg/CoordinateSystemNode) there are functions to convert from lat/long to geocentric and back. You can these to calcuate the XYZ at which to place your model. Then use the XYZ to create an osg/MatrixTransform, and put your model node under it.
Glenn Waldron : Pelican Mapping : http://pelicanmapping.com : +1.703.652.4791 On Sat, Feb 28, 2009 at 4:53 PM, B. McMahan <osgfo...@tevs.eu> wrote: > Pardon the elementary question...I'm a newbie with OSG and VPB. I've > search around but haven't found a simple example that illustrates what I'd > like to do. > > Essentially, I've built a VPB whole-earth database and got it loaded in my > application. There are two things I'd like to do at this point: > > 1) Place a model at some point relative to the earth by latitude, > longitude, and possibly altitude. > > 2) Perform an intersection test from the mouse cursor to find the latitude > and longitude of the point on the earth's surface that the mouse is > intersecting with. In short, if the mouse is hovering over the planet's > surface, transform that point from screen coords to world coordinates, and > then convert to lat/lon. > > At this point, given my little experience with OSG at the moment on how to > proceed. I'm really not looking for hand-outs...but if you can point me to > a simple (easily digestible) example I'd be just as grateful. > > Thank you in advance! > > ------------------ > Read this topic online here: > http://forum.openscenegraph.org/viewtopic.php?p=7694#7694 > > > > > > _______________________________________________ > osg-users mailing list > osg-users@lists.openscenegraph.org > http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org >
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