Am Dienstag 20 Februar 2007 09:57 schrieb Dene: > Hi Chris > > > Are the landcover db boundaries vector-based? If they are then there > > is no reason why the terrain could not be created more accurately at > > those boundaries, for example between land and rivers. > > As far s I know, at the moment the land cover is triangle based. ie each > triangle in the processed terrain is assigned a landcover texture from > sea, ocean etc to urban etc. This and the simplification of the terrain > & elevation error limits cause the landcover boundaries to be distorted.
Depends on what you see as land cover db. The default terrain is created from SRTM for elevation data and vmap0 for land use (not 100% sure) and the line features like rivers, roads, railways... Unfortunately vmap0 only codes the course of the line features, not their width. Thats why rivers are uniformly 25 meters wide (except where they are wide enough to be coded as polygons in vmap0, mostly estuaries), roads are 10 meters, ... That means there is no way to improve the river shores from the original data alone. Several people (including me) have created small parts of scenery by digitizing scanned survey maps, which tremendously increased visual appearance. Yet time consumption (~30h for a 10x10km area from 1:25.000) and unclear copyright/terms of use issues don't let it scale well. Anyway, Martin Spott already created a data base to collect vector data contributions and provide a single base for scenery creation. http://www.custom-scenery.org/Landcover-DB.212.0.html Regards, Thomas -- PhD Student, Dept. Animal Physiology, HU Berlin Tel +49 30 2093 6173, Fax +49 30 2093 6375 ------------------------------------------------------------------------- Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT & business topics through brief surveys-and earn cash http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV _______________________________________________ Flightgear-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/flightgear-users
