Quite a few years ago we had a debate, because we had to choose between two sets of shoreline data:
1. GSHSS was very nicely detailed (every little cove and point), but about 1 mile off for the Great Lakes, leaving shoreline airports either far inland or floating in the middle of a lake. 2. Vmap0 was much lower resolution (only big bays and points), but actually had the Great Lakes shorelines in roughly the right place. Since I was doing most of the TerraGear coding that year, I forced through vmap0, but a lot of people objected -- I thought it was OK for the Toronto harbourfront, but I don't remember for certain, and I don't know what FlightGear is using now. All the best, David On Sun, Mar 28, 2010 at 5:18 PM, David Slocombe <sloco...@vex.net> wrote: > On Sunday 2010-03-28 David Megginson wrote: >> Now, quite a few years later, the Great Lakes are still >> broken in our default scenery, and as a result, FlightGear >> looks ridiculous to any new user who comes and tries flying >> in near cities such as Toronto, Rochester, Buffalo, Cleveland, >> Detroit, Chicago, or Milwaukee. > > Sometimes pictures really *are* worth a thousand words. I think > this is one of those times. > > I've put up on the Web (temporarily: they won't be there forever) > three screen snaps: > > Please go to http://www.vex.net/~slocombe/fgfs-pics-of-CYTZ/ for > pictures illustrating the problems of CYTZ (Toronto/City Centre), > which is on an island in Lake Ontario just offshore from Toronto's > downtown area. > > 1. cytz-from-08-apprch.png : CYTZ from the approach viewpoint > of Runway 08 (08/26 is the principal runway of this extremely > busy airport: Bombardier Dash8-Q400's take off or land about > every 20 minutes, and in between that traffic Cessna 150's and > 172's practise circuits or transit to/from Toronto's > "practice area" to the East. I'm one of the student pilots these days. > > The fact that, in fgfs, the water is 240 feet below its real-world level > is only a small part of the problem (in fact if that were the > only problem one could just pretend one is practising landings > on aircraft carriers). The terrain data, intersected by the > water at its current level, makes the shoreline wildly wrong... > > 2. cytz-overhead-at-40Kft.png : This is taken with the UFO > tool at 40,000 ft., looking straight down. > > 3. google-image-cytz.png : a snap of what Google has for > a satellite shot, to compare with the previous shot. > > I'm not convinced that the terrain data that fgfs uses is > sufficiently detailed to capture even the approximate > shape of the Toronto Islands (what CYTZ is on the Western > end of), let alone the Leslie Spit and docklands to the East. > So I'm not sure how different this is going to look if the > water-level were correct. But surely it would make a difference, > and there are > 700 miles of shoreline for Lake Ontario, > and another > 800 miles for Lake Erie: all of this would > be affected by a "fix". I presume the shoreline in the > St. Lawrence River near Montreal must be seriously wrong too. > > BTW, Just For Kicks, I can fly *under* CYTZ. It doesn't > seem to do me damage, and fgfs doesn't even crash! :-) > > Thanks everyone for the great achievement that fgfs is. > It was fgfs that got me sufficiently enthused about flying > to decide to get my PPL. > > David Slocombe > Toronto Canada. > > ------------------------------------------------------------------------------ > Download Intel® Parallel Studio Eval > Try the new software tools for yourself. Speed compiling, find bugs > proactively, and fine-tune applications for parallel performance. > See why Intel Parallel Studio got high marks during beta. > http://p.sf.net/sfu/intel-sw-dev > _______________________________________________ > Flightgear-devel mailing list > Flightgear-devel@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/flightgear-devel > ------------------------------------------------------------------------------ Download Intel® Parallel Studio Eval Try the new software tools for yourself. Speed compiling, find bugs proactively, and fine-tune applications for parallel performance. See why Intel Parallel Studio got high marks during beta. http://p.sf.net/sfu/intel-sw-dev _______________________________________________ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel
