FS9 terrain mesh

[simondix]

I have a freeware mesh I downloaded years ago from Avsim or Flightsim. It is quite accurate and for instance I left Benbecula yesterday and the hills were realistic and identifiable. I am familiar with the area. If you PM me I will send it to you. The Cuillins on Skye are so so but it must be almost impossible to get them to look realistic anyway.

[hobby]

For emfrat:

Goodness me! Long ago (50 years ago) as a keen ATC cadet undergoing instruction for the 'aircrew' syllabus for the leading or senior cadet proficiency badge we learned that a map or chart of an area including a landmass had four requirements:

Shape, distance, bearing and area.

We were also told that as the earth really was curved that it was impossible to draw a map or chart on a flat surface with a landmass which portrayed all four requirements accurately - one had to sacrifice, by distortion, one of the four requirements.

I am astonished to read that right up to and including FS9 Microsoft adopted the 'flat earth' policy. Glad to read that the earth is portrayed more accurately in FSX. But I am still holding on to FS9! 'Flat earth' does explain the UK coastline distortion very well and Norway, Greenland and Svelbard must therefore be even more inaccurate. I suppose that distotionmay also apply to New Zealand as seen in MSFS up to FS9.

[emfrat]

Cheers , hobby -
I am a recalcitrant 'Flat Earther' meself, since my very good-looking FS9 just has too much blood sweat and tears invested in it to be abandoned. Bear in mind, that when MSFS first appeared, it was a very advanced bit of programming and the mapping method was the best compromise. It was only about the time of FS2004 that machines which could use more advanced processing became available at a reasonable price, so it was really only a matter of time before the modelling was revamped.
The main difference is that in FS9 and earlier, the scenery tiles are rectangular, whereas in FSX they are trapezoidal with slightly curved sides, the narrow end being the one further from the Equator. So within any FSX tile, while the latitude lines will be the same as FS9, the longitude lines will taper towards the narrow end; as a result, an FSX object placed at the bottom centre of a tile will also appear at the correct position in FS9, but an object in the top left corner (say) will be correct in FSX but displaced to the left in FS9, even though the co-ordinates are the same.
More coffee needed - it is too early in the morning for all this thinking ;-)

MikeW

[hobby]

According to a fairly recent forum survey about half of us are still 'flat earth society' members.

[emfrat]

That's enough to bring down a government - what are we waiting for ?

MikeW

[05pricej]

Hi, somewhere on simviation is some detailed mesh for the entire world :o, im just looking for it now, ill edit my post when i find it.

for the fs9 version: http://simviation.com/fsdterrainsrtm.htm

if anyone wants an fsx version: http://simviation.com/fsx_terrainmesh.htm

hope it helps

[simondix]

I have tried to send my Mesh but for some reason it won.t complete sending it. I have zipped the file OK. But no joy when it comes to actually sending it.

[Chris Trott]

Actually, Microsoft tried to do "Round Earth" in FS2000 with some poor results partially due to processing, but mostly due to inability to get it to "work right" when they compiled the AIRAC charting data into the program which resulted in location errors of well over .5 miles in many areas for airports. They returned to the "Flat Earth" in FS2002 and FS2004 while they worked with their data providers to find a way to get the airports and such to plot correctly on a "Round Earth" as the AIRAC charting data being used is produced for mapping on a flat map, thus has in-built corrections for the type of projection used by the cartography software that creates the charts. This results in the errors when trying to project the coordinates on a spherical surface. The Lat/Lon locations of individual objects (like fixes, VORs, NDBs, etc.) could be placed properly in a spherical reference as they could use the AIRAC navigation data for that (which does not contain projection calibration), but the runways, taxiways, ramps, cities, roads, and geographic features were where the problem originated.

Many times this is where problems with software arises, especially those which try to model the entire world. It's extremely difficult to get reliable data that is a "true" projection as all have some sort of calibration or bias built into them for various applications to result in proper display of the objects in the application the data was originally intended for. When you then try to take something that was designed for 2D display and make it 3D, you get errors and with something like Flight Sim, those errors are a problem as they result in disagreements in data being provided to the user. It's one of those things where nature makes it seem so simple but when you try to recreate it, it proves to be extremely complex to do well.

[hobby]

Through the kind offices of a well known forum member I have now been able to acquire Terramesh Europe. Have undertaken some short tests in UK but more personal flying required for full test over a 'flat earth' by MS!

[simondix]

Glad everything is OK. Good luck with Scotflight.