Discussion regarding real world terrain data for AH.

[Ghastly]

Rather than continue in Middog's thread regarding his Resources page, I thought I'd bring this out into it's own thread.

When using real-world data as a template for creating terrains in AH, I'm an utter n00b.  I understand the basics of the geometry and rudimentary geography involved, but when it comes to what's available for real world data, where to get it, what the various datasets are comprised of, what they may or may not cost, for me it's been like attending a medical seminar. Even just figuring out what's being discussed is a laborious process - it's apparently English, yes, but every 3rd word refers to something that I'm unfamiliar with and must root out the meaning of.

I chose to use GTOPO30 because:

a) I could actually find the data
b) it could be downloaded for free
c) at approx 1 km resolution, it's not a bad "match" to AH - "close enough" to be able to "plunk" a chunk down as a template with minimal conversion into an AH terrain with a 1/2 mile resolution with only minor distortion.  (especially when you are talking about at most a 256 mi square area for an MA map, and if you are just working with compiling features onto a section of terrain, often much less).
d) it was documented well enough that I could sort out what I was getting in the files.
e) Did I mention that it was freely downloadable?
f)  The amount of spatial distortion and flaws in the data didn't seem likely to be highly problematic considering the use and scale of the maps I'd be incorporating features into.

I saw no reason to purchase finer resolution datasets that I barely understand, and then have to do additional work with much larger files to "throw out" information that I can't use anyway.

However, GTOPO30 was simply my first best attempt as a complete n00b at getting some real world data to incorporate into the map I'm constructing, and while it certainly seems "good enough" for the most part for my purposes, perhaps some of you guys have better sources?

Having already gone through the learning curve I'm just starting, and limiting the choices to free or data sets available at a minimal cost, what exactly do/would you guys that have more experience at this use?

And if not GTOPO30, where exactly do you get them?  And if not free, what does the data set you recommend cost?

[NHawk]

To be perfectly honest, I avoid real world terrains in most cases.

Can you say "Boring"?

If I do use them they are GTOPO and I usually "enhance" them with artificial terrain.

The CM team is usually more apt to use real world data for historical terrains than someone making an MA terrain.

[Dux]

NHawk is right... the CM Terrain Team strives to make the terrains as realistic as possible, something which MA or H2H terrains really not be terribly concerned with.

FWIW, I use DTED Level 1 data for our terrains... I have access to it through my job, and by the time it's sampled down to AH sizes, it's no longer of sensitive resolution.

No matter what format you use, beware of the quality of your data... just because you downloaded it from some official site doesn't guarantee that the data is necessarily accurate. I've seen some data sets (Great Britain, for example) that were terrible, not even close.

But once again, close enough is surely good enough for most purposes.

[Easyscor]

What? You think someone is going to impart two years of their own research, just because you asked?

Alright then, for those who do want to build historically correct terrains, grab a fresh coffee and sit back for the plain English summary.

USGS DEM files:
Compiled about 15 or 20 years ago.
Covers the entire world.
The concept was to provide an elevation data point every 30 degree seconds along both longitude and latitude lines. NHawk listed the sources of the data in the other thread but as the longitude lines converge at the poles, the latitude data points come closer together.
If you’re still with me so far, consider that the data sets didn’t quite line up and are shifted almost uniformly a fraction of a mile along both longitude and latitude but fortunately it’s not enough to affect you for your stated purpose.
The DEM files come with a land use / terrain type data file. The only problem is it’s a Goode projection which is a bastard combination of two standard map projections, and pulling useful information for the whole earth is pain.
DEM files are free, are relatively easy to find and have been around long enough to have support from many application developers, except for the USGS as you learned.

DTED files:
Compiled and updated more recently.
Covers parts of the world of military interest with notable exceptions such as the UK.
Level 0 is also 30 degree second data between latitudes 50 N and 50 S iirc but above that they change spacing, I don’t have the number at the moment. Standard DTEDs cover a grid that is only one degree on a side. You might not find data for the part of the world you want but if you do it will be of good quality. As this format is newer then DEM, it has less support.
Level 1 DTED and above, are military grade and not available to the general public while
Level 0 DTEDs are supposed to be freely available. Finding a free source can be tough, see McFarland link in mrmidi’s thread.

GLOBE files:
Compiled more recently.
Covers the entire world.
Combines DEM and DTEDs in a large file format similar to the DEM format.
I haven’t tracked developer support and it’s probably spotty as it’s a newer format but the files are a free download.

As Dux cautioned, your data sources can have widely varying degrees of accuracy within the same data base, and no matter how accurate your data, if the application you’re using processes that data incorrectly, it may be several terrains and months later before you discover how bad the error is.

[Dux]

Good thread.

Also, when it comes to importing real-world data into whatever program you use, be wary of the way that multiple files get stitched together. Sometimes tiles don't match up the greyscale values with their adjacent counterparts, making a hard edged elevation "jump" that looks really obvious and unnatural when viewed in the game.

I find I get the best results by gathering whatever data I need, and exporting as quickly as I can into an image format; once it's in Photoshop, I do all my adjusting and balancing there.

[NHawk]

Easy...First let me say I prefer 5 hour old coffee. If it doesn't remove at least 1% of the hair from my head...it's no good.

Now for those looking for information..... Don't take that first sentence of Easy's wrong. Sharing knowledge isn't a bad thing, but there is a limit to what each person will share. Hard work and research has a price that is different for each person. Some of us have been using the TE from darned close to day 1 and can make it jump through hoops if we want.

But in general, each of us will share what we feel we can. Beyond that it's up to you to piece the puzzle together to come up to your own style and methods to create a terrain. Otherwise, every terrain will have the same style and how boring would that be?

Anyway, Compello was a DEM file based terrain. Which for some reason always seems to be the first type of MA terrain someone tries. I'd seriously suggest that not be the direction people go for the MA. In general, it's not as easy as it looks.

Always keep this in mind... For scenarios, real world terrains make sense. For MA use, real world usually does not mean playable. Or in other words, it's usually boring from a terrain standpoint UNLESS you mix different areas of the world onto one map.

I really hope that doesn't sound bad, because it's not intended to be.

[Easyscor]

I considered that NHawk, but I’m not worried. The hacks will still produce poor terrains even with the best tools and data because they won’t put in the effort to learn the difference; the amount of hand work that it takes. I’m posting for those of us who will use the information to speed the development so we can spend more time doing the hand work and build ever more impressive terrains. There’s no tool which can build terrains of the quality expected for the SEA or even the MA without extensive rework, and that’s never likely to change. Who knows, maybe one or two of those dog-eared MA terrains can be replaced if enough people are given a hand up with the process.

[Ghastly]

Thanks guys for clarifying what's out there somewhat.  And rest easy, Easycor, we're both going to be dead a long time before I would ever get even close to being capable of building a real world terrain to scale - no matter how much of a brain dump I was to get and from who.  And I'm sure most of those who are trying to sort out this stuff are the same - so most of a couple of years of experience isn't going to do us much good.  

Part of the reason I've asked though is this: the hardest part of sorting out this kind of stuff via forum searches is that you often can't tell what "level" the information discussed is at, and much of the time, to what purpose the information exchange is intended between the people who are discussing it.    And by the time you can, you already know enough to know whether it's applicable to what you're doing in the first place - a catch 22.   So you spend a lot of time trying to figure out stuff that's worthless (to you anyway for your current purpose).  

FWIW,  I have no desire to gain access to anyone's "secrets" - frankly, I'm at the level of "insert key in ignition, turn and hope " - knowing how Mario Andretti takes corners is academic.  At this point, I'm just trying to sort out which paths are worth walking.

Anyway, so far, I've been able to create a realistic appearing terrain by layering my wholely fabricated heightmap that has the gross terrain levels I desire on the continents I designed with a psuedo-random terrain generated by Terragen.  By varying the transparency of the overlay, I can make wholly realistic looking hills and valleys, at varying "intensity levels".   By overlaying that with a drawing layer, I can place realistic looking river valleys where I want them, and it all looks "wicked pissa".

But then - I hit mountains.  Frankly, my ability to create mountains sucks.  The ones from the terrain generators I've tried all have a certain "sameness" about them that feels markedly "artificial" when I fly/drive around them offline - I really don't want to place them on my terrain.  I know what the mountains I grew up near looked like - and that ain't it!  Drawing them by hand is not my forte, so....

I decided I wanted to blend a few sectors length of "real looking ones" into my terrain where I've determined that I want the mountain ranges to be,  and the best place I could think of to get real looking mountains was to use real ones.  I mean, how hard could it be .... ???

Having finally just come up with a way to easily create a bitmap from a GTOPO30 DEM, I'd planned to go forward that way, but was wondering if in my inexperience I was missing another source that might be far more easily incorporated.

That's all!

and thanks to everyone again.

[Easyscor]

If people aren’t thinking about, and learning how to build real world terrains, our source of terrain builders for the SEA will dry up, so the more the merrier.

Most of us start by building terrains for H2H. It’s a great way to pick up experience and you’ll get immediate feedback from the players when your killer objects also kill their frame rates. Watch out that you don’t pick up too many bad habits or take too many shortcuts, figure out how things are really supposed to be done, and what works best.

[NHawk]

Originally posted by Ghastly
.....I decided I wanted to blend a few sectors length of "real looking ones" into my terrain where I've determined that I want the mountain ranges to be,  and the best place I could think of to get real looking mountains was to use real ones.  I mean, how hard could it be .... ???
.....

Ah.. you have snatched the pebble from my hand young grasshopper.

It is time for you to go out on your own.

[croduh]

Talk about complicating things...

[Ghastly]

Artistry (as in the act of creation) is always complicated...  

I'm sure there are those who can start from almost anything and create a terrain they are happy with. But mine is in my head, trying to find it's way out - I can see it, drive it, and fly it with my eyes closed.  And I won't be satisfied until what I make matches what I envision perfectly, so it's worth the agony and aggravation.

(*Sounds pretty dopey, huh?)