How does one...

[CBris]

...make a mesh?

I mean, I have seen scenery addons use a 3D object to make something like a sand dune or a small escarpment.

OK, I know nothing of the black arts of landscaping, but it strikes me that if we can draw an ordnance survey type map with many concentric lines to indicate ground elevation, then there must be a way to do so in the sim.

So any pointers to sensible tutorials for non-magical peoples?

[NoNewMessages]

...make a mesh?

I mean, I have seen scenery addons use a 3D object to make something like a sand dune or a small escarpment.

OK, I know nothing of the black arts of landscaping, but it strikes me that if we can draw an ordnance survey type map with many concentric lines to indicate ground elevation, then there must be a way to do so in the sim.

So any pointers to sensible tutorials for non-magical peoples?

First, find good source and hope it doesn't involve a lot of work.

Second, if the first doesn't apply then you're in for some fun work. There are many tools available that can create a DEM, which would eventually become a BGL after much screaming and throwing things. Some tools will take a survey type map and with proper setup create a DEM file, but then that would probably entail a lot of time verifying the data output.

Third, one could always et up a manual file that could be used, but who wants to set up a 5,000 pt by 5,000 pt manual data file?

[IanP]

The answer is SBuilderX and a lot of playing... ;)

The Ordinance Survey are a bit of a bad bunch to mention as they, unfortunately, will not play nicely with simmers. They want hundreds/thousands of pounds for mesh data and only supply it in formats that they use internally. Most of the formats used by FS conversion tools are based on GIS data available cheaply or for free from US Government agencies (e.g. SRTM, USGS). You also, remember, can't trace the lines on OS maps without paying them a large amount in usage fees and royalties - the Trainsim crowd found that out to their cost... So you have to be careful what you use to base your mesh on, depending on where you want to improve the mesh for!

There are various tutorials for SBuilderX depending on what you want to do with it specifically - I'd suggest looking at http://www.fsdeveloper.com as that's where I found the ones I used, albeit some time ago.

[CBris]

I'll take a look. Basically I am just curious and thinking more along the lines of localised meshes in very accurate detail.

Thanks for the pointers.

[GaryGB]

Hi Chris:

Is this for North America /PNW ? :ques:

If instead it is for UK, Germany or France, there are 5 Meter resolution add-on terrain meshes already available that may still benefit from use of additional local high detail "blended / skirted" Flattens at airports.

Such Flattens would not involve the challenge of working with DEMS via the FSX SDK "Resample" route; one would use the "SHP2VEC" method instead. :iidea:

GaryGB

[GaryGB]

Oops... how do I delete a duplicate post here ? :engel016:

GaryGB

[CBris]

No... I am really wanting to know how a mesh is made for FSX. Irrespective of where in the world.

[GaryGB]

Well, first of all there is very limited high resolution DEMs (< 76, 30, or 19 Meters between elevation data points) available outside the USA other than the data sets from NextMap (...and also those "we citizens" paid for which are in the posession of government agencies that don't intend to make it available to just anyone if they can help it).

So for areas outside North America / PNW, I suggested the NextMap meshes already available for FSX because they are cost effective... and far higher detail than one could even download a DEM for free of charge.

NextMap has their own Lear Jet they fly grids with world wide in prospective markets using IFSAR to gather data which can eventually become 4.75 Meter DEMS (after post processing by the end user to keep things affordable).

FSDeveloper would certainly be a good place to learn about "making a mesh of things" ! :mixedsmi:

GaryGB

[Cazzie]

Chris,

I never made mesh for any flight sim, but years ago I used a 3DEM mesh engine for Terragen images. One had to download DEM maps from a USGS source for local areas, which were generally 19-meter.

Here is a source for many various DEMs world-wide, some in 30in. and some in super high 1-in resolution.

http://www.viewfinderpanoramas.org/dem3.html

There is a link to the freeware 3DEM program that is required.

Good luck.

Caz

[GaryGB]

Hi Cazzie:

That is still a nicely informative resource website. ;)

The units on that website represented by the " symbols are arc seconds of geographic distance rather than inches though, so one would quickly see that many data sources outside the USA, and many data sources that use the SRTM and ASTER data are lower resolution in terms of the distance between elevation data points.


As an example of spatial data resolution and its availability:

"The USGS has assembled a seamless digital elevation dataset of the United States with a 1 arc second (30 meter) resolution. There is also a large collection of 1/3 arc second (10 m) data covering much of the U.S. This is an active archive, meaning these data are being replaced as better data are available. Individual tiles of these data can be downloaded in several formats from the Seamless Data Distribution System (http://seamless.usgs.gov/) (SDDS) of the USGS. "


A mix of high and low resolution data sources often proves necessary when cross-correlating land elevation data with water body data to achieve a more accurate representation of terrain surfaces.


An introductory overview of DEM data sources:

http://www.yale.edu/ceo/Documentation/dem.html


BTW: 3DEM was a great program to tinker with... I wonder if the author will do any more with it ?


Hope this helps ! :mixedsmi:

GaryGB

[NoNewMessages]

BTW: 3DEM was a great program to tinker with... I wonder if the author will do any more with it ?

Nope, it has seen the last release and the closing of the web site. But the last version is still available for download here;

http://freegeographytools.com/2009/3dem-website-is-gone-but-3dem-still-available-here

I used 3DEM to overlay some USGS maps on top of the mesh I made for a couple of the islands in Hawai'i, which I still have somewhere. It's cool to look at and see how well things all line up

[GaryGB]

Hi Chris:

I replied to your post at FSDeveloper if you're still curious about FS terrain mesh methodology:

http://www.fsdeveloper.com/forum/showthread.php?p=117238#post117238


GaryGB

[CBris]

hmmm, okayyy... blame ACES then ;)

So if you want the Dolomites or Meteora or whatever, you make a 3D model. Why are some scenery addons so poor then - i.e. those where the aircraft shadows disappear under a terrain object?

Never mind. I realise that simulation isn't there yet. We're going to need more CPU power.

And yet there is 3D landscape generation software that can create rugged scenery better. I know - 20 square miles is not the whole world.

And then again... FS manages to create odd spires in the sim sometimes.

Mine is not to reason why...