Hi, On Montag 23 Mai 2005 10:52, BONNEVILLE David wrote: > How could I get the terrain elevation at a given lat/lon at runtime ? > Could you point me to the right way ? That depends on what you need.
In src/Scenery/hitlist.* there are the fgCurrentElev(...) functions which could be used to get a list of intersection points of the scenery with the line from the given position towards the earths center. You can see in src/Scenery/tilemgr.cxx in the function FGTileMgr::updateCurrentElevAtPos(...) how this could be used to compute a single altitude value. Alternatively, you can use that ground cache in src/FDM/groundcache* to get such scenery altitude. You first have to build that cache for a given position with prepare_ground_cache. Then you can query for the altitude by get_agl. The basic difference is that the fgCurrentElev function walks the whole scenery each time you ask for an altitude. The ground cache functions build up a small flat subset of the scenery into an own small scenegraph. If you need miltiple terrain altitude values at close but different points in the scene the ground cache will be better. If you need only a single altitude or values far from each other you need to use fgCurrentElev. Greetings Mathias -- Mathias Fröhlich, email: [EMAIL PROTECTED] _______________________________________________ Flightgear-devel mailing list Flightgear-devel@flightgear.org http://mail.flightgear.org/mailman/listinfo/flightgear-devel 2f585eeea02e2c79d7b1d8c4963bae2d